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Sample records for ghz sige power

  1. Cryogenic operation of a 24 GHz MMIC SiGe HBT medium power amplifier

    International Nuclear Information System (INIS)

    Qin, Guoxuan; Jiang, Ningyue; Seo, Jung-Hun; Cho, Namki; Van der Weide, Daniel; Ma, Zhenqiang; Ponchak, George E; Ma, Pingxi; Stetson, Scott; Racanelli, Marco

    2010-01-01

    The performance of a SiGe heterojunction bipolar transistor (HBT) millimetre-wave power amplifier (PA) operating at cryogenic temperature was reported and analysed for the first time. A 24 GHz two-stage medium PA employing common-emitter and common-base SiGe power HBTs in the first and the second stage, respectively, showed a significant power gain increase at 77 K in comparison with that measured at room temperature. Detailed analyses indicate that cryogenic operation of SiGe HBT-based PAs mainly affects (improves) the performance of the SiGe HBTs in the circuits due to transconductance enhancement through magnified, favourable changes of SiGe bandgap due to cooling (ΔE g /kT) and minimized thermal effects, with little influence on the passive components of the circuits

  2. Gas spectroscopy system with 245 GHz transmitter and receiver in SiGe BiCMOS

    Science.gov (United States)

    Schmalz, Klaus; Rothbart, Nick; Borngräber, Johannes; Yilmaz, Selahattin Berk; Kissinger, Dietmar; Hübers, Heinz-Wilhelm

    2017-02-01

    The implementation of an integrated mm-wave transmitter (TX) and receiver (RX) in SiGe BiCMOS or CMOS technology offers a path towards a compact and low-cost system for gas spectroscopy. Previously, we have demonstrated TXs and RXs for spectroscopy at 238 -252 GHz and 495 - 497 GHz using external phase-locked loops (PLLs) with signal generators for the reference frequency ramps. Here, we present a more compact system by using two external fractional-N PLLs allowing frequency ramps for the TX and RX, and for TX with superimposed frequency shift keying (FSK) or reference frequency modulation realized by a direct digital synthesizer (DDS) or an arbitrary waveform generator. The 1.9 m folded gas absorption cell, the vacuum pumps, as well as the TX and RX are placed on a portable breadboard with dimensions of 75 cm x 45 cm. The system performance is evaluated by high-resolution absorption spectra of gaseous methanol at 13 Pa for 241 - 242 GHz. The 2f (second harmonic) content of the absorption spectrum of the methanol was obtained by detecting the IF power of RX using a diode power sensor connected to a lock-in amplifier. The reference frequency modulation reveals a higher SNR (signal-noise-ratio) of 98 within 32 s acquisition compared to 66 for FSK. The setup allows for jumping to preselected frequency regions according to the spectral signature thus reducing the acquisition time by up to one order of magnitude.

  3. 270GHz SiGe BiCMOS manufacturing process platform for mmWave applications

    Science.gov (United States)

    Kar-Roy, Arjun; Preisler, Edward J.; Talor, George; Yan, Zhixin; Booth, Roger; Zheng, Jie; Chaudhry, Samir; Howard, David; Racanelli, Marco

    2011-11-01

    TowerJazz has been offering the high volume commercial SiGe BiCMOS process technology platform, SBC18, for more than a decade. In this paper, we describe the TowerJazz SBC18H3 SiGe BiCMOS process which integrates a production ready 240GHz FT / 270 GHz FMAX SiGe HBT on a 1.8V/3.3V dual gate oxide CMOS process in the SBC18 technology platform. The high-speed NPNs in SBC18H3 process have demonstrated NFMIN of ~2dB at 40GHz, a BVceo of 1.6V and a dc current gain of 1200. This state-of-the-art process also comes with P-I-N diodes with high isolation and low insertion losses, Schottky diodes capable of exceeding cut-off frequencies of 1THz, high density stacked MIM capacitors, MOS and high performance junction varactors characterized up to 50GHz, thick upper metal layers for inductors, and various resistors such as low value and high value unsilicided poly resistors, metal and nwell resistors. Applications of the SBC18H3 platform for millimeter-wave products for automotive radars, phased array radars and Wband imaging are presented.

  4. Application of a Pelletron accelerator to study total dose radiation effects on 50 GHz SiGe HBTs

    Energy Technology Data Exchange (ETDEWEB)

    Praveen, K.C.; Pushpa, N.; Naik, P.S. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India); Cressler, John D. [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA (United States); Tripathi, Ambuj [Inter University Accelerator Centre (IUAC), New Delhi 110 067 (India); Gnana Prakash, A.P., E-mail: gnanaprakash@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Total dose effects of 50 MeV Li3+ ion on 50 GHz SiGe HBTs is investigated. Black-Right-Pointing-Pointer Ion irradiated results were compared with Co-60 gamma results. Black-Right-Pointing-Pointer 50 MeV Li ions create more damage in E-B spacer oxide when compared to Co-60 gamma radiation. Black-Right-Pointing-Pointer Co-60 gamma radiation create more damage in STI oxide when compared to 50 MeV Li ions. Black-Right-Pointing-Pointer Worst case total dose radiation effects can be studied using Pelletron accelerator facilities. - Abstract: We have investigated the effects of 50 MeV lithium ion irradiation on the DC electrical characteristics of first-generation silicon-germanium heterojunction bipolar transistors (50 GHz SiGe HBTs) in the dose range of 600 krad to 100 Mrad. The results of 50 MeV Li{sup 3+} ion irradiation on the SiGe HBTs are compared with 63 MeV proton and Co-60 gamma irradiation results in the same dose range in order to understand the damage induced by different LET species. The radiation response of emitter-base (EB) spacer oxide and shallow trench isolation (STI) oxide to different irradiation types are discussed in this paper. We have also focused on the efficacy in the application of a Pelletron accelerator to study total dose irradiation studies in SiGe HBTs.

  5. SiGe HBTs Optimization for Wireless Power Amplifier Applications

    Directory of Open Access Journals (Sweden)

    Pierre-Marie Mans

    2010-01-01

    Full Text Available This paper deals with SiGe HBTs optimization for power amplifier applications dedicated to wireless communications. In this work, we investigate the fT-BVCEO tradeoff by various collector optimization schemes such as epilayer thickness and dopant concentration, and SIC and CAP characteristics. Furthermore, a new trapezoidal base Germanium (Ge profile is proposed. Thanks to this profile, precise control of Ge content at the metallurgical emitter-base junction is obtained. Gain stability is obtained for a wide range of temperatures through tuning the emitter-base junction Ge percent. Finally, a comprehensive investigation of Ge introduction into the collector (backside Ge profile is conducted in order to improve the fT values at high injection levels.

  6. The effects of hot carrier and swift heavy ion irradiation on electrical characteristics of advanced 200 GHz SiGe HBTs

    Energy Technology Data Exchange (ETDEWEB)

    Vinayakprasanna, N. H.; Praveen, K. C.; Prakash, A. P. Gnana, E-mail: gnanaprakash@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore-570006 (India); Cressler, J. D. [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta-30332, GA (United States)

    2016-05-23

    The 200 GHz SiGe HBTs were irradiated with 80 MeV Carbon ions up to a total dose of 100 Mrad to understand the degradation in electrical characteristics. The degradation in the electrical characteristics of SiGe HBTs was also studied by mixed mode electrical stress up to 10,000 s. The electrical characteristics were measured before and after every total dose and after fixed stress time. The normalized peak h{sub FE} of the stressed and irradiated SiGe HBTs are compared to estimate the equivalent stress time for a particular total dose. These correlations are drawn for the first time and the results will establish a systematic relation between stress time and total dose.

  7. The effects of hot carrier and swift heavy ion irradiation on electrical characteristics of advanced 200 GHz SiGe HBTs

    International Nuclear Information System (INIS)

    Vinayakprasanna, N. H.; Praveen, K. C.; Prakash, A. P. Gnana; Cressler, J. D.

    2016-01-01

    The 200 GHz SiGe HBTs were irradiated with 80 MeV Carbon ions up to a total dose of 100 Mrad to understand the degradation in electrical characteristics. The degradation in the electrical characteristics of SiGe HBTs was also studied by mixed mode electrical stress up to 10,000 s. The electrical characteristics were measured before and after every total dose and after fixed stress time. The normalized peak h_F_E of the stressed and irradiated SiGe HBTs are compared to estimate the equivalent stress time for a particular total dose. These correlations are drawn for the first time and the results will establish a systematic relation between stress time and total dose.

  8. High power, 140 GHz gyrotron

    International Nuclear Information System (INIS)

    Kreischer, K.E.; Temkin, R.J.; Mulligan, W.J.; MacCabe, S.; Chaplya, R.

    1982-01-01

    The design and construction of a pulsed 100 kW, 140 GHz gyrotron is described. Initial gyrotron operation is expected in early 1982. Advances in gyrotron theory have also been carried out in support of this experimental research. The application of gyrotrons to plasma diagnostics is also under investigation. (author)

  9. 30 GHz High Power Production for CLIC

    CERN Document Server

    Syratchev, I V

    2006-01-01

    The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and excite preferentially the synchronous TM01 mode at 30 GHz. The RF power produced (several hundred MW) is collected at the downstream end of the structure by means of the Power Extractor and conveyed to the main linac structure. The PETS geometry is a result of multiple compromises between beam stability along a single decelerator sector (600 m) and the active length of the structure to match the main linac RF power needs and layout. Surface electric and magnetic fields, power extraction method, HOM damping, ON/OFF capability and fabrication technology were all evaluated to provide a reliable design.

  10. A 24 GHz integrated SiGe BiCMOS vital signs detection radar front-end

    DEFF Research Database (Denmark)

    Jensen, Brian Sveistrup; Johansen, Tom K.; Zhurbenko, Vitaliy

    2013-01-01

    In this paper a 24 GHz integrated front-end transceiver for vital signs detection (VSD) radars is described. The heterodyne radar transceiver integrates LO buffering and quadrature splitting circuits, up- and down-conversion SSB mixers and two cascaded receiver LNA's. The chip has been manufactured...

  11. Thermal stability improvement of a multiple finger power SiGe heterojunction bipolar transistor under different power dissipations using non-uniform finger spacing

    International Nuclear Information System (INIS)

    Chen Liang; Zhang Wan-Rong; Jin Dong-Yue; Shen Pei; Xie Hong-Yun; Ding Chun-Bao; Xiao Ying; Sun Bo-Tao; Wang Ren-Qing

    2011-01-01

    A method of non-uniform finger spacing is proposed to enhance thermal stability of a multiple finger power SiGe heterojunction bipolar transistor under different power dissipations. Temperature distribution on the emitter fingers of a multi-finger SiGe heterojunction bipolar transistor is studied using a numerical electro-thermal model. The results show that the SiGe heterojunction bipolar transistor with non-uniform finger spacing has a small temperature difference between fingers compared with a traditional uniform finger spacing heterojunction bipolar transistor at the same power dissipation. What is most important is that the ability to improve temperature non-uniformity is not weakened as power dissipation increases. So the method of non-uniform finger spacing is very effective in enhancing the thermal stability and the power handing capability of power device. Experimental results verify our conclusions. (interdisciplinary physics and related areas of science and technology)

  12. 45-GHz and 60-GHz 90 nm CMOS power amplifiers with a fully symmetrical 8-way transformer power combiner

    Institute of Scientific and Technical Information of China (English)

    Zhengdong JIANG; Kaizhe GUO; Peng HUANG; Yiming FAN; Chenxi ZHAO; Yongling BAN; Jun LIU; Kai KANG

    2017-01-01

    In this paper,45 GHz and 60 GHz power amplifiers (PAs) with high output power have been successfully designed by using 90 nm CMOS process.The 45 GHz (60 GHz) PA consists of two (four) differential stages.The sizes of transistors have been designed in an appropriate way so as to trade-off gain,efficiency and stability.Due to limited supply voltage and low breakdown voltage of CMOS MOSFET compared with the traditional Ⅲ-Ⅴ technologies,the technique of power combining has been applied to achieve a high output power.In particular,a novel 8-way distributed active transformer power combiner has been proposed for realizing such mm-wave PA.The proposed transformer combiner with a fully symmetrical layout can improve its input impedance balance at mm-wave frequency regime significantly.Taking its advantages of this novel transformer based power combiner,our realized 45 GHz (60 GHz) mm-wave PA has achieved the gain of 20.3 dB (16.8 dB),the maximum PAE of 14.5% (13.4%) and the saturated output power of 21 dBm (21 dBm) with the 1.2 V supply voltage.

  13. An 8–18 GHz broadband high power amplifier

    International Nuclear Information System (INIS)

    Wang Lifa; Yang Ruixia; Li Yanlei; Wu Jingfeng

    2011-01-01

    An 8–18 GHz broadband high power amplifier (HPA) with a hybrid integrated circuit (HIC) is designed and fabricated. This HPA is achieved with the use of a 4-fingered micro-strip Lange coupler in a GaAs MMIC process. In order to decrease electromagnetic interference, a multilayer AlN material with good heat dissipation is adopted as the carrier of the power amplifier. When the input power is 25 dBm, the saturated power of the continuous wave (CW) outputted by the power amplifier is more than 39 dBm within the frequency range of 8–13 GHz, while it is more than 38.6 dBm within other frequency ranges. We obtain the peak power output, 39.4 dBm, at the frequency of 11.9 GHz. In the whole frequency band, the power-added efficiency is more than 18%. When the input power is 18 dBm, the small signal gain is 15.7 ± 0.7 dB. The dimensions of the HPA are 25 × 15 × 1.5 mm 3 . (semiconductor integrated circuits)

  14. Flexible Low-power SiGe HBT Amplifier Circuits for Fast Single-shot Spin Readout

    Science.gov (United States)

    England, Troy; Lilly, Michael; Curry, Matthew; Carr, Stephen; Carroll, Malcolm

    Fast, low-power quantum state readout is one of many challenges facing quantum information processing. Single electron transistors (SETs) are potentially fast, sensitive detectors for performing spin readout of electrons bound to Si:P donors. From a circuit perspective, however, their output impedance and nonlinear conductance are ill suited to drive the parasitic capacitance of coaxial conductors used in cryogenic environments, necessitating a cryogenic amplification stage. We will introduce two new amplifier topologies that provide excellent gain versus power tradeoffs using silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs). The AC HBT allows in-situ adjustment of power dissipation during an experiment and can provide gain in the millikelvin temperature regime while dissipating less than 500 nW. The AC Current Amplifier maximizes gain at nearly 800 A/A. We will also show results of using these amplifiers with SETs at 4 K. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000. Flexible Low-power SiGe HBT Amplifier Circuits for Fast Single-shot Spin Readout.

  15. A 12 GHz RF Power Source for the CLIC Study

    Energy Technology Data Exchange (ETDEWEB)

    Schirm, Karl; /CERN; Curt, Stephane; /CERN; Dobert, Steffen; /CERN; McMonagle, Gerard; /CERN; Rossat, Ghislain; /CERN; Syratchev, Igor; /CERN; Timeo, Luca; /CERN; Haase, Andrew /SLAC; Jensen, Aaron; /SLAC; Jongewaard, Erik; /SLAC; Nantista, Christopher; /SLAC; Sprehn, Daryl; /SLAC; Vlieks, Arnold; /SLAC; Hamdi, Abdallah; /Saclay; Peauger, Franck; /Saclay; Kuzikov, Sergey; /Nizhnii Novgorod, IAP; Vikharev, Alexandr; /Nizhnii Novgorod, IAP

    2012-07-03

    The CLIC RF frequency has been changed in 2008 from the initial 30 GHz to the European X-band 11.9942 GHz permitting beam independent power production using klystrons for CLIC accelerating structure testing. A design and fabrication contract for five klystrons at that frequency has been signed by different parties with SLAC. France (IRFU, CEA Saclay) is contributing a solid state modulator purchased in industry and specific 12 GHz RF network components to the CLIC study. RF pulses over 120 MW peak at 230 ns length will be obtained by using a novel SLED-I type pulse compression scheme designed and fabricated by IAP, Nizhny Novgorod, Russia. The X-band power test stand is being installed in the CLIC Test Facility CTF3 for independent structure and component testing in a bunker, but allowing, in a later stage, for powering RF components in the CTF3 beam lines. The design of the facility, results from commissioning of the RF power source and the expected performance of the Test Facility are reported.

  16. A 12 GHZ RF Power source for the CLIC study

    CERN Document Server

    Peauger, F; Curt, S; Doebert, S; McMonagle, G; Rossat, G; Schirm, KM; Syratchev, I; Timeo, L; Kuzikhov, S; Vikharev, AA; Haase, A; Sprehn, D; Jensen, A; Jongewaard, EN; Nantista, CD; Vlieks, A

    2010-01-01

    The CLIC RF frequency has been changed in 2008 from the initial 30 GHz to the European X-band 11.9942 GHz permitting beam independent power production using klystrons for CLIC accelerating structure testing. A design and fabrication contract for five klystrons at that frequency has been signed by different parties with SLAC. France (IRFU, CEA Saclay) is contributing a solid state modulator purchased in industry and specific 12 GHz RF network components to the CLIC study. RF pulses over 120 MW peak at 230 ns length will be obtained by using a novel SLED-I type pulse compression scheme designed and fabricated by IAP, Nizhny Novgorod, Russia. The X-band power test stand is being installed in the CLIC Test Facility CTF3 for independent structure and component testing in a bunker, but allowing, in a later stage, for powering RF components in the CTF3 beam lines. The design of the facility, results from commissioning of the RF power source and the expected performance of the Test Facility are reported.

  17. A program of high power microwave source research and development from 8 GHz to 600 GHz

    International Nuclear Information System (INIS)

    Granatstein, V.L.; Antonsen, T.M. Jr.; Bidwell, S.; Booske, J.; Carmel, Y.; Destler, W.W.; Kehs, R.A.; Latham, P.E.; Levush, B.; Lou, W.R.; Mayergoyz, I.D.; Minami, K.; Radack, D.J.

    1990-01-01

    We review research results both on a plasma filled, backward wave oscillator (BWO), and on a free electron laser (FEL) driven by a sheet electron beam. Recently, it was demonstrated that a plasma filled BWO driven by an intense relativistic electron beam can generate hundreds of megawatts of microwave radiation at an unusually high efficiency of 40% compared with a typical efficiency of ∼10% in a BWO without a background plasma. Furthermore, the enhanced efficiency can be maintained even for large electron beam currents approaching the vacuum space charge limiting current, and we anticipate this might hold even for larger current values. Theoretical studies and numerical simulations indicate that the enhanced efficiency as well as a lower value for the start oscillation current in the linear regime may be due to the finite length of the BWO circuit coupled with modification of the dispersion relation due to the background plasma. In the case of our FEL studies, we present designs for a 1 MW, CW, tapered FEL amplifier operating at frequencies of 280 GHz and 560 GHz. A short wiggler period (ell w ∼ 1 cm) is combined with a sheet beam of electrons having energy ∼1 MeV. Depressed collector techniques would allow the main power supply rating to be reduced to ∼200 kV. Efficient sheet beam transport (>99%) has been demonstrated through 10 wiggler periods, and transport through 60 wiggler periods is currently under study. Finally, plans for a proof-of-principle tapered FEL amplifier experiment at 94 GHz are presented. 8 refs., 7 figs

  18. High power testing of a 17 GHz photocathode RF gun

    International Nuclear Information System (INIS)

    Chen, S.C.; Danly, B.G.; Gonichon, J.

    1995-01-01

    The physics and technological issues involved in high gradient particle acceleration at high microwave (RF) frequencies are under study at MIT. The 17 GHz photocathode RF gun has a 1 1/2 cell (π mode) room temperature cooper cavity. High power tests have been conducted at 5-10 MW levels with 100 ns pulses. A maximum surface electric field of 250 MV/m was achieved. This corresponds to an average on-axis gradient of 150 MeV/m. The gradient was also verified by a preliminary electron beam energy measurement. Even high gradients are expected in our next cavity design

  19. 5.2 GHz variable-gain amplifier and power amplifier driver for WLAN IEEE 802.11a transmitter front-end

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xuelian; Yan Jun; Shi Yin [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Foster, Dai Fa, E-mail: xlzhang@semi.ac.c [Department of Electrical and Computer Engineering, Auburn University, Auburn, AL 36849-5201 (United States)

    2009-01-15

    A 5.2 GHz variable-gain amplifier (VGA) and a power amplifier (PA) driver are designed for WLAN IEEE 802.11a monolithic RFIC. The VGA and the PA driver are implemented in a 50 GHz 0.35 mum SiGe BiCMOS technology and occupy 1.12 x 1.25 mm{sup 2} die area. The VGA with effective temperature compensation is controlled by 5 bits and has a gain range of 34 dB. The PA driver with tuned loads utilizes a differential input, single-ended output topology, and the tuned loads resonate at 5.2 GHz. The maximum overall gain of the VGA and the PA driver is 29 dB with the output third-order intercept point (OIP3) of 11 dBm. The gain drift over the temperature varying from -30 to 85 deg. C converges within +-3 dB. The total current consumption is 45 mA under a 2.85 V power supply.

  20. InP MMIC Chip Set for Power Sources Covering 80-170 GHz

    Science.gov (United States)

    Ngo, Catherine

    2001-01-01

    We will present a Monolithic Millimeter-wave Integrated Circuit (MMIC) chip set which provides high output-power sources for driving diode frequency multipliers into the terahertz range. The chip set was fabricated at HRL Laboratories using a 0.1-micrometer gate-length InAlAs/InGaAs/InP high electron mobility transistor (HEMT) process, and features transistors with an f(sub max) above 600 GHz. The HRL InP HEMT process has already demonstrated amplifiers in the 60-200 GHz range. In this paper, these high frequency HEMTs form the basis for power sources up to 170 GHz. A number of state-of-the-art InP HEMT MMICs will be presented. These include voltage-controlled and fixed-tuned oscillators, power amplifiers, and an active doubler. We will first discuss an 80 GHz voltage-controlled oscillator with 5 GHz of tunability and at least 17 mW of output power, as well as a 120 GHz oscillator providing 7 mW of output power. In addition, we will present results of a power amplifier which covers the full WRIO waveguide band (75-110 GHz), and provides 40-50 mW of output power. Furthermore, we will present an active doubler at 164 GHz providing 8% bandwidth, 3 mW of output power, and an unprecedented 2 dB of conversion loss for an InP HEMT MMIC at this frequency. Finally, we will demonstrate a power amplifier to cover 140-170 GHz with 15-25 mW of output power and 8 dB gain. These components can form a power source in the 155-165 GHz range by cascading the 80 GHz oscillator, W-band power amplifier, 164 GHz active doubler and final 140-170 GHz power amplifier for a stable, compact local oscillator subsystem, which could be used for atmospheric science or astrophysics radiometers.

  1. Megawatt Power Level 120 GHz Gyrotrons for ITER Start-Up

    Energy Technology Data Exchange (ETDEWEB)

    Choi, E M; Marchewka, C; Mastovsky, I; Shapiro, M A; Sirigiri, J R; Temkin, R J [MIT - Plasma Science and Fusion Center, NW16-186, 167 Albany Street, Cambridge, MA 02139 (United States)

    2005-01-01

    We report operation of a 110 GHz gyrotron with 1.67 MW of output power measured in short pulses (3{mu}s) at an efficiency of 42% in the TE{sub 22,6} mode. We also present a preliminary design of a 1 MW, 120 GHz gyrotron for ITER start-up with an efficiency greater than 50%.

  2. Megawatt Power Level 120 GHz Gyrotrons for ITER Start-Up

    International Nuclear Information System (INIS)

    Choi, E M; Marchewka, C; Mastovsky, I; Shapiro, M A; Sirigiri, J R; Temkin, R J

    2005-01-01

    We report operation of a 110 GHz gyrotron with 1.67 MW of output power measured in short pulses (3μs) at an efficiency of 42% in the TE 22,6 mode. We also present a preliminary design of a 1 MW, 120 GHz gyrotron for ITER start-up with an efficiency greater than 50%

  3. Design and operation of 140 GHz gyrotron oscillators for power levels up to 1 MW CW

    Energy Technology Data Exchange (ETDEWEB)

    Jory, H.; Bier, R.; Craig, L.J.; Felch, K.; Ives, L.; Lopez, N.; Spang, S.

    1986-12-01

    Varian has designed and tested 140 GHz gyrotron oscillators that have generated output powers of 100 kW CW and 200 kW for 1 ms pulses. Upcoming tubes will be designed to operate at power levels of 200 kW CW and ultimately up to 1 MW CW. The important design considerations which are addressed in the higher power tubes include the design of the electron gun, interaction circuit, and output window. These issues will be discussed and the results of the earlier 140 GHz gyrotron work at Varian will be summarized.

  4. Design and operation of 140 GHz gyrotron oscillators for power levels up to 1 MW CW

    International Nuclear Information System (INIS)

    Jory, H.; Bier, R.; Craig, L.J.; Felch, K.; Ives, L.; Lopez, N.; Spang, S.

    1986-12-01

    Varian has designed and tested 140 GHz gyrotron oscillators that have generated output powers of 100 kW CW and 200 kW for 1 ms pulses. Upcoming tubes will be designed to operate at power levels of 200 kW CW and ultimately up to 1 MW CW. The important design considerations which are addressed in the higher power tubes include the design of the electron gun, interaction circuit, and output window. These issues will be discussed and the results of the earlier 140 GHz gyrotron work at Varian will be summarized

  5. 1 GHz GaAs Buck Converter for High Power Amplifier Modulation Applications

    NARCIS (Netherlands)

    Busking, E.B.; Hek, A.P. de; Vliet, F.E. van

    2012-01-01

    A fully integrated 1 GHz buck converter output stage, including on-chip inductor and DC output filtering has been realized, in a standard high-voltage breakdown GaAs MMIC technology. This is a significant step forward in designing highspeed power control of supply-modulated HPAs (high power

  6. Low cost low power 24 GHz FMCW radar transceiver for indoor presence detection

    NARCIS (Netherlands)

    Suijker, E.M.; Bolt, R.J.; Wanum, M. van; Heijningen, M. van; Maas, A.P.M.; Vliet, F.E. van

    2014-01-01

    In this paper a first time right 24 GHz FMCW radar transceiver is presented. The MMIC has a low power consumption of 86 mW and an output power of -10 dBm. Due to the integrated IF amplifier, the conversion gain of the receiver is 51 dB and the base band signals are directly processed with an ADC.

  7. The reliability studies of nano-engineered SiGe HBTs using Pelletron accelerator

    Science.gov (United States)

    Prakash, A. P. Gnana; Praveen, K. C.; Pushpa, N.; Cressler, John D.

    2015-05-01

    The effects of high energy ions on the electrical characteristics of silicon-germanium heterojunction bipolar transistors (SiGe HBTs) were studied in the total dose of ranging from 600 krad to 100 Mrad (Si). The two generations (50 GHz and 200 GHz) of SiGe HBTs were exposed to 50 MeV lithium, 75 MeV boron and 100 MeV oxygen ions. The electrical characteristics of SiGe HBTs were studied before and after irradiation. The SiGe HBTs were exposed to 60Co gamma radiation in the same total dose. The results are systematically compared in order to understand the interaction of ions and ionizing radiation with SiGe HBTs.

  8. The reliability studies of nano-engineered SiGe HBTs using Pelletron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, A. P. Gnana, E-mail: gnanaprakash@physics.uni-mysore.ac.in; Praveen, K. C. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore, Karnataka-570006 (India); Pushpa, N. [Department of PG Studies in Physics, JSS College, Ooty Road, Mysore-570025 (India); Cressler, John D. [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332 (United States)

    2015-05-15

    The effects of high energy ions on the electrical characteristics of silicon-germanium heterojunction bipolar transistors (SiGe HBTs) were studied in the total dose of ranging from 600 krad to 100 Mrad (Si). The two generations (50 GHz and 200 GHz) of SiGe HBTs were exposed to 50 MeV lithium, 75 MeV boron and 100 MeV oxygen ions. The electrical characteristics of SiGe HBTs were studied before and after irradiation. The SiGe HBTs were exposed to {sup 60}Co gamma radiation in the same total dose. The results are systematically compared in order to understand the interaction of ions and ionizing radiation with SiGe HBTs.

  9. CMOS 60-GHz and E-band power amplifiers and transmitters

    CERN Document Server

    Zhao, Dixian

    2015-01-01

    This book focuses on the development of design techniques and methodologies for 60-GHz and E-band power amplifiers and transmitters at device, circuit and layout levels. The authors show the recent development of millimeter-wave design techniques, especially of power amplifiers and transmitters, and presents novel design concepts, such as “power transistor layout” and “4-way parallel-series power combiner”, that can enhance the output power and efficiency of power amplifiers in a compact silicon area. Five state-of-the-art 60-GHz and E-band designs with measured results are demonstrated to prove the effectiveness of the design concepts and hands-on methodologies presented. This book serves as a valuable reference for circuit designers to develop millimeter-wave building blocks for future 5G applications.

  10. 75 GHz InP DHBT power amplifier based on two-stacked transistors

    DEFF Research Database (Denmark)

    Squartecchia, Michele; Midili, Virginio; Johansen, Tom Keinicke

    2017-01-01

    In this paper we present the design and measurements of a two-stage 75-GHz InP Double Heterojunction Bipolar Transistor (DHBT) power amplifier (PA). An optimized two-stacked transistor power cell has been designed, which represents the building block in the power stage as well as in the driver st......, the power amplifier exhibits a small signal gain of G = 12.6 dB, output power at 1-dB compression of Pout, 1dB = 18.6 dBm and a saturated output power of Psat > 21.4 dBm....

  11. Ceramic Power Extractor Design at 15.6 GHz

    CERN Document Server

    Smirnov, Alexei Yu; Yi, Rong; Yu, David

    2005-01-01

    Power extractor and coupler designs developed for an experiment planned at the 12th beam harmonic of the upgraded Advanced Wakefield Accelerator (AWA) facility is described. New features are an upstream HOM dielectric damper with additional tapering, and a single-port coupler considered in two variants. Performance analysis includes coupler geometric tolerances, overvoltage, dipole mode wake and BBU; and wakefield losses induced in the damper.

  12. A low power and low phase-noise 91 96 GHz VCO in 90 nm CMOS

    Science.gov (United States)

    Lin, Yo-Sheng; Lan, Kai-Siang; Chuang, Ming-Yuan; Lin, Yu-Ching

    2018-06-01

    This paper reports a 94 GHz CMOS voltage-controlled oscillator (VCO) using both the negative capacitance (NC) technique and series-peaking output power and phase noise (PN) enhancement technique. NC is achieved by adding two variable LC networks to the source nodes of the active circuit of the VCO. NMOSFET varicaps are adopted as the required capacitors of the LC networks. In comparison with the conventional one, the proposed active circuit substantially decreases the input capacitance (Cin) to zero or even a negative value. This leads to operation (or oscillation) frequency (OF) increase and tuning range (TR) enhancement of the VCO. The VCO dissipates 8.3 mW at 1 V supply. The measured TR of the VCO is 91 96 GHz, close to the simulated (92.1 96.7 GHz) and the calculated one (92.2 98.2 GHz). In addition, at 1 MHz offset from 95.16 GHz, the VCO attains an excellent PN of - 98.3 dBc/Hz. This leads to a figure-of-merit (FOM) of -188.5 dBc/Hz, a remarkable result for a V- or W-band CMOS VCO. The chip size of the VCO is 0.75 × 0.42 mm2, i.e. 0.315 mm2.

  13. Recent developments using TowerJazz SiGe BiCMOS platform for mmWave and THz applications

    Science.gov (United States)

    Kar-Roy, Arjun; Howard, David; Preisler, Edward J.; Racanelli, Marco

    2013-05-01

    In this paper, we report on the highest speed 240GHz/340GHz FT/FMAX NPN which is now available for product designs in the SBC18H4 process variant of TowerJazz's mature 0.18μm SBC18 silicon germanium (SiGe) BiCMOS technology platform. NFMIN of ~2dB at 50GHz has been obtained with these NPNs. We also describe the integration of earlier generation NPNs with FT/FMAX of 240GHz/280GHz into SBC13H3, a 0.13μm SiGe BiCMOS technology platform. Next, we detail the integration of the deep silicon via (DSV), through silicon via (TSV), high-resistivity substrate, sub-field stitching and hybrid-stitching capability into the 0.18μm SBC18 technology platform to enable higher performance and highly integrated product designs. The integration of SBC18H3 into a thick-film SOI substrate, with essentially unchanged FT and FMAX, is also described. We also report on recent circuit demonstrations using the SBC18H3 platform: (1) a 4-element phased-array 70-100GHz broadband transmit and receive chip with flat saturated power greater than 5dBm and conversion gain of 33dB; (2) a fully integrated W-band 9-element phase-controllable array with responsivity of 800MV/W and receiver NETD is 0.45K with 20ms integration time; (3) a 16-element 4x4 phased-array transmitter with scanning in both the E- and H-planes with maximum EIRP of 23-25 dBm at 100-110GHz; (4) a power efficient 200GHz VCO with -7.25dBm output power and tuning range of 3.5%; and (5) a 320GHz 16-element imaging receiver array with responsivity of 18KV/W at 315GHz, a 3dB bandwidth of 25GHz and a low NEP of 34pW/Hz1/2. Wafer-scale large-die implementation of the phased-arrays and mmWave imagers using stitching in TowerJazz SBC18 process are also discussed.

  14. Substrate Effects in Wideband SiGe HBT Mixer Circuits

    DEFF Research Database (Denmark)

    Johansen, Tom Keinicke; Vidkjær, Jens; Krozer, Viktor

    2005-01-01

    are also applied to predict short distance substrate coupling effects. Simulation results using extracted equivalent circuit models and substrate coupling networks are compared with experimental results obtained on a wideband mixer circuit implemented in a 0.35 μm, 60 GHz ft SiGe HBT BiCMOS process.......In this paper, the influence from substrate effects on the performance of wideband SiGe HBT mixer circuits is investigated. Equivalent circuit models including substrate networks are extracted from on-wafer test structures and compared with electromagnetic simulations. Electromagnetic simulations...

  15. A SiGe High Gain and Highly Linear F-Band Single-Balanced Subharmonic Mixer

    OpenAIRE

    Seyedhosseinzadeh, Neda; Nabavi, Abdolreza; Carpenter, Sona; He, Zhongxia Simon; Bao, Mingquan; Zirath, Herbert

    2017-01-01

    A compact, broadband, high gain, second-order active down-converter subharmonic mixer is demonstrated using a 130-nm SiGe BiCMOS technology. The mixer adopts a bottom-LO Gilbert topology, on-chip RF and LO baluns and two emitter-follower buffers to realize a high gain wideband operation in both RF and IF frequencies. The measured performance exhibits a flat conversion gain (CG) of about 11 dB from 90 to 130 GHz with an average LO power of +3 dBm and high 2LO-RF isolation better than 60 dB. Th...

  16. A low power 20 GHz comparator in 90 nm COMS technology

    Science.gov (United States)

    Kai, Tang; Qiao, Meng; Zhigong, Wang; Ting, Guo

    2014-05-01

    A low power 20 GHz CMOS dynamic latched regeneration comparator for ultra-high-speed, low-power analog-to-digital converters (ADCs) is proposed. The time constant in both the tracking and regeneration phases of the latch are analyzed based on the small signal model. A dynamic source-common logic (SCL) topology is adopted in the master-slave latch to increase the tracking and regeneration speeds. Implemented in 90 nm CMOS technology, this comparator only occupies a die area of 65 × 150 μm2 with a power dissipation of 14 mW from a 1.2 V power supply. The measurement results show that the comparator can work up to 20 GHz. Operating with an input frequency of 1 GHz, the circuit can oversample up to 20 Giga-sampling-per-second (GSps) with 5 bits resolution; while operating at Nyquist, the comparator can sample up to 20 GSps with 4 bits resolution. The comparator has been successfully used in a 20 GSps flash ADC and the circuit can be also used in other high speed applications.

  17. An applicable 5.8 GHz wireless power transmission system with rough beamforming to Project Loon

    Directory of Open Access Journals (Sweden)

    Chang-Jun Ahn

    2016-06-01

    Full Text Available In recent, Google proposed the Project Loon being developed with the mission of providing internet access to rural and remote areas using high-altitude balloons. In this paper, we describe an applicable prototype of 5.8 GHz wireless power transmission system with rough beamforming method to Project Loon. From the measurement results, transmit beamforming phased array antenna can transmit power more efficiently compared to a horn antenna and array antenna without beamforming with increasing the transmission distance. For the transmission distance of 1000 mm, transmit beamforming phased array antenna can obtain higher received power about 1.46 times compared to array antenna without transmit beamforming.

  18. Design and High Power Measurements of a 3 GHz Rotary Joint for Medical Applications

    CERN Document Server

    Degiovanni, Alberto; Garlasche, Marco; Giner-Navarro, Jorge; Magagnin, Paolo; Mcmonagle, Gerard; Syratchev, Igor; Wuensch, Walter

    2016-01-01

    The TUrning LInac for Protontherapy (TULIP) project requires the transport of RF power from modulator/klystron systems at rest on the floor to the linac structures mounted on a rotating gantry, via a waveguide system that can operate over a range of angles of rotation. A waveguide rotary joint capable of transporting RF power at 3 GHz and up to 20 MW has been designed and built in collaboration between TERA Foundation, CERN Beams and CERN Engineering Departments. A high-power test of the prototype has been performed at the CLIC Test Facility (CTF3), at CERN. The design and the results of the tests are reported in this article.

  19. Construction and Testing of a 21 GHz Ceramic Based Power Extractor

    CERN Document Server

    Newsham, D; Carron, G; Döbert, Steffen; Gai, W; Konecny, R; Liu, W; Smirnov, A Yu; Thorndahl, L; Wilson, Ian H; Wuensch, Walter; Yu, D

    2003-01-01

    A ceramic based power extractor [1] operating at 21 GHz was built by DULY Research Inc. and tested at CTF2, the CERN Linear Collider (CLIC) Test Facility. The structure includes a ceramic extractor section, a 2-output-port, circular-to-rectangular waveguide coupler, and a 3-port rectangular waveguide combiner that provides for a single output waveguide. Results of cold tests and full beam tests are presented and compared with theoretical and numerical models.

  20. High power tests of dressed supconducting 1.3 GHz RF cavities

    Energy Technology Data Exchange (ETDEWEB)

    Hocker, A.; Harms, E.R.; Lunin, A.; Sukhanov, A.; /Fermilab

    2011-03-01

    A single-cavity test cryostat is used to conduct pulsed high power RF tests of superconducting 1.3 GHz RF cavities at 2 K. The cavities under test are welded inside individual helium vessels and are outfitted ('dressed') with a fundamental power coupler, higher-order mode couplers, magnetic shielding, a blade tuner, and piezoelectric tuners. The cavity performance is evaluated in terms of accelerating gradient, unloaded quality factor, and field emission, and the functionality of the auxiliary components is verified. Test results from the first set of dressed cavities are presented here.

  1. Status and outlook for high power processing of 1.3 GHz TESLA multicell cavities

    International Nuclear Information System (INIS)

    Kirchgessner, J.; Barnes, P.; Graber, J.; Metzger, D.; Mofat, D.; Muller, H.; Padamsee, H.; Sears, J.; Tigner, M.; Matheisen, A.

    1993-01-01

    In order to increase the usable accelerating gradient in Superconducting TESLA cavities, the field emission threshold barrier must be raised. As has been previously demonstrated on S-band cavities, a way to accomplish this is with the use of high peak power RF processing. A transmitter with a peak power of 2 Mwatt and 300 μsec pulse length has been assembled and has been used to process TESLA cavities. Several five cell TESLA cavities at 1.3 GHz have been manufactured for this purpose. This transmitter and the cavities will be described and the results of the tests will be presented

  2. A low power 3-5 GHz CMOS UWB receiver front-end

    International Nuclear Information System (INIS)

    Li Weinan; Huang Yumei; Hong Zhiliang

    2009-01-01

    A novel low power RF receiver front-end for 3-5 GHz UWB is presented. Designed in the 0.13 μm CMOS process, the direct conversion receiver features a wideband balun-coupled noise cancelling transconductance input stage, followed by quadrature passive mixers and transimpedance loading amplifiers. Measurement results show that the receiver achieves an input return loss below -8.5 dB across the 3.1-4.7 GHz frequency range, maximum voltage conversion gain of 27 dB, minimum noise figure of 4 dB, IIP3 of -11.5 dBm, and IIP2 of 33 dBm. Working under 1.2 V supply voltage, the receiver consumes total current of 18 mA including 10 mA by on-chip quadrature LO signal generation and buffer circuits. The chip area with pads is 1.1 x 1.5 mm 2 .

  3. Remote powering platform for implantable sensor systems at 2.45 GHz.

    Science.gov (United States)

    Kazanc, Onur; Yilmaz, Gurkan; Maloberti, Franco; Dehollain, Catherine

    2014-01-01

    Far-field remotely powered sensor systems enable long distance operation for low-power sensor systems. In this work, we demonstrate a remote powering platform with a miniaturized antenna and remote powering base station operating at 2.45 GHz. The rectenna, which is the energy receiving and conversion element of the sensor system, is designed and measured. The measurements for the tag are performed within 15 cm distance from the remote powering base station. The realized gain of the tag antenna is measured as -3.3 dB, which is 0.5 dB close to the simulations, where simulated realized gain is -2.8 dB.

  4. High power tests of an electroforming cavity operating at 11.424 GHz

    Science.gov (United States)

    Dolgashev, V. A.; Gatti, G.; Higashi, Y.; Leonardi, O.; Lewandowski, J. R.; Marcelli, A.; Rosenzweig, J.; Spataro, B.; Tantawi, S. G.; Yeremian, D. A.

    2016-03-01

    The achievement of ultra high accelerating gradients is mandatory in order to fabricate compact accelerators at 11.424 GHz for scientific and industrial applications. An extensive experimental and theoretical program to determine a reliable ultra high gradient operation of the future linear accelerators is under way in many laboratories. In particular, systematic studies on the 11.424 GHz frequency accelerator structures, R&D on new materials and the associated microwave technology are in progress to achieve accelerating gradients well above 120 MeV/m. Among the many, the electroforming procedure is a promising approach to manufacture high performance RF devices in order to avoid the high temperature brazing and to produce precise RF structures. We report here the characterization of a hard high gradient RF accelerating structure at 11.424 GHz fabricated using the electroforming technique. Low-level RF measurements and high power RF tests carried out at the SLAC National Accelerator Laboratory on this prototype are presented and discussed. In addition, we present also a possible layout where the water-cooling of irises based on the electroforming process has been considered for the first time.

  5. Initial results for a 170 GHz high power ITER waveguide component test stand

    Science.gov (United States)

    Bigelow, Timothy; Barker, Alan; Dukes, Carl; Killough, Stephen; Kaufman, Michael; White, John; Bell, Gary; Hanson, Greg; Rasmussen, Dave

    2014-10-01

    A high power microwave test stand is being setup at ORNL to enable prototype testing of 170 GHz cw waveguide components being developed for the ITER ECH system. The ITER ECH system will utilize 63.5 mm diameter evacuated corrugated waveguide and will have 24 >150 m long runs. A 170 GHz 1 MW class gyrotron is being developed by Communications and Power Industries and is nearing completion. A HVDC power supply, water-cooling and control system has been partially tested in preparation for arrival of the gyrotron. The power supply and water-cooling system are being designed to operate for >3600 second pulses to simulate the operating conditions planned for the ITER ECH system. The gyrotron Gaussian beam output has a single mirror for focusing into a 63.5 mm corrugated waveguide in the vertical plane. The output beam and mirror are enclosed in an evacuated duct with absorber for stray radiation. Beam alignment with the waveguide is a critical task so a combination of mirror tilt adjustments and a bellows for offsets will be provided. Analysis of thermal patterns on thin witness plates will provide gyrotron mode purity and waveguide coupling efficiency data. Pre-prototype waveguide components and two dummy loads are available for initial operational testing of the gyrotron. ORNL is managed by UT-Battelle, LLC, for the U.S. Dept. of Energy under Contract DE-AC-05-00OR22725.

  6. 8 GHz, high power, microwave system for heating of thermonuclear plasmas

    International Nuclear Information System (INIS)

    Di Giovenale, S.; Fortunato, T.; Mirizzi, F.; Roccon, M.; Sassi, M.; Tuccillo, A.A.; Maffia, G.; Baldi, L.

    1993-01-01

    The Frascati Tokamak Upgrade (FTU) is a machine included in the European Thermonuclear Fusion Program aimed at investigating high density plasmas in the presence of powerful additional RF heating systems. The Lower Hybrid Resonant Heating (LHRH) system, based on 9 independent modules, works at 8 GHz, and will generate, at full performances, a total amount of 9 MW, in the pulsed regime (pulse length = 1 s, duty cycle = 1/600). The microwave power source is a gyrotron oscillator, developed by Thomson Tubes Electroniques (France) for this specific application, and capable of producing up to 1 MW. An overmoded, low loss, circular waveguide transmits the RF power toward the plasma; an array of 12x4 rectangular waveguides (the 'grill') launches this power into the plasma. The paper describes the LHRH system for FTU and analyses both its main performances and experimental results

  7. Use of an untuned cavity for absolute power measurements of the harmonics above 100 GHz from an IMPATT oscillator

    Science.gov (United States)

    Llewellyn-Jones, D. T.; Knight, R. J.; Gebbie, H. A.

    1980-07-01

    A new technique of measuring absolute power exploiting an untuned cavity and Fourier spectroscopy has been used to examine the power spectrum of the harmonics and other overtones produced by a 95 GHz IMPATT oscillator. The conditions which favor the production of a rich harmonic spectrum are not those which maximize the fundamental power. Under some conditions of mismatch at the fundamental frequency it is possible to produce over 200 microW of harmonic power in the 100-200 GHz region comparable with the fundamental power from the oscillator.

  8. A high linearity SiGe HBT LNA for GPS receiver

    International Nuclear Information System (INIS)

    Luo Yanbin; Shi Jian; Ma Chengyan; Gan Yebing; Qian Min

    2014-01-01

    A high linearity 1.575 GHz SiGe:HBT low noise amplifier (LNA) for global positioning system applications is described. The bipolar cascoded with an MOSFET LNA was fabricated in a commercial 0.18 μm SiGe BiCMOS process. A resistor bias feed circuit with a feedback resistor was designed for the LNA input transistor to improve its intermodulation and compression performance. The packaged chip tested on board has displayed a noise figure of 1.11 dB, a power gain of 18 dB, an output 1 dB compression point of +7.8 dBm and an input third-order intercept point of +1.8 dBm. The chip occupies a 500 × 560 μm 2 area and consumes 3.6 mA from a 2.85 V power supply. (semiconductor integrated circuits)

  9. A 35 GHz wireless millimeter-wave power sensor based on GaAs micromachining technology

    International Nuclear Information System (INIS)

    Wang, De-bo; Liao, Xiao-ping

    2012-01-01

    A novel MEMS wireless millimeter-wave power sensor based on GaAs MMIC technology is presented in this paper. The principle of this wireless millimeter-wave power sensor is explained. It is designed and fabricated using MEMS technology and the GaAs MMIC process. With the millimeter-wave power range from 0.1 to 80 mW, the sensitivity of the wireless millimeter-wave power sensor is about 0.246 mV mW −1 at 35 GHz. In order to verify the power detection capability, this wireless power sensor is mounted on a PCB which influences the microwave performance of the CPW-fed antenna including the return loss and the radiation pattern. The frequency-dependent characteristic and the degree-dependent characteristic of this wireless power sensor are researched. Furthermore, in addition to the combination of the advantages of CPW-fed antenna with the advantages of the thermoelectric power sensor, another significant advantage of this wireless millimeter-wave power sensor is that it can be integrated with MMICs and other planar connecting circuit structures with zero dc power consumption. These features make it suitable for various applications ranging from the environment or space radiation detection systems to radar receiver and transmitter systems. (paper)

  10. 2.45 GHz Class E Power Amplifier for a Transmitter Combining LINC and EER

    Directory of Open Access Journals (Sweden)

    M. Dirix

    2009-01-01

    Full Text Available A 10 W class-E RF power amplifier (PA is designed and fabricated using a Cree GaN HEMT. The proposed PA uses an innovative input circuit to optimize band with. At 2.45 GHz the PA achieves a PAE of 60 % at an outputpower of 40 dBm. The resulting amplifier is simulated and constructed using a transmissionline topology. Two of these amplifiers are fabricated on a single board for outphasing application. Their suitability for outphasing application and supply modulation is investigated. 

  11. Observations of electron heating during 28 GHz microwave power application in proto-MPEX

    Science.gov (United States)

    Biewer, T. M.; Bigelow, T. S.; Caneses, J. F.; Diem, S. J.; Green, D. L.; Kafle, N.; Rapp, J.; Proto-MPEX Team

    2018-02-01

    The Prototype Material Plasma Exposure Experiment at the Oak Ridge National Laboratory utilizes a variety of power systems to generate and deliver a high heat flux plasma onto the surface of material targets. In the experiments described here, a deuterium plasma is produced via a ˜100 kW, 13.56 MHz RF helicon source, to which ˜20 kW of 28 GHz microwave power is applied. The electron density and temperature profiles are measured using a Thomson scattering (TS) diagnostic, and indicate that the electron density is centrally peaked. In the core of the plasma column, the electron density is higher than the cut-off density (˜0.9 × 1019 m-3) for the launched mixture of X- and O-mode electron cyclotron heating waves to propagate. TS measurements indicate electron temperature increases from ˜5 eV to ˜20 eV during 28 GHz power application when the neutral deuterium pressure is reduced below 0.13 Pa (˜1 mTorr.).

  12. Commissioning of the 28 GHz ECRH power transmission line for the TJ-II stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Fernández, J., E-mail: jose.martinez@ciemat.es [Laboratorio Nacional de Fusión (LNF), Centro de Investigaciones Tecnológicas, Medioambientales y Tecnológicas (CIEMAT), Av/Complutense 40, 28040 Madrid (Spain); Cappa, Á. [Laboratorio Nacional de Fusión (LNF), Centro de Investigaciones Tecnológicas, Medioambientales y Tecnológicas (CIEMAT), Av/Complutense 40, 28040 Madrid (Spain); Chirkov, A. [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation); Ros, A.; Tolkachev, A.; Catalán, G.; Soleto, A.; Redondo, M. [Laboratorio Nacional de Fusión (LNF), Centro de Investigaciones Tecnológicas, Medioambientales y Tecnológicas (CIEMAT), Av/Complutense 40, 28040 Madrid (Spain); Doane, J.L.; Anderson, J.P. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States)

    2015-10-15

    Highlights: • The 28 GHz power transmission line of the TJ-II stellarator is described. • Mismatch and alignment problems are covered, presenting infrared measurements. • Beam distortion in the matching optics unit led to unwanted modes in the waveguide. • After a redesign distortion was eliminated and coupling maximized. • Final measurements suggest finer alignment must be performed. - Abstract: The commissioning of the 28 GHz power transmission line of the TJ-II stellarator, designed for the excitation of electron Bernstein waves (EBW) through the O-X-B mode conversion process, is presented in this paper. Based upon a comprehensive set of thermal measurements, its purpose is to go into details about the several problems that arouse during the whole process, namely higher order modes excitation because of the wider beam size and alignment mismatches at the waveguide mouth. All these drawbacks may have prevented the correct O-X mode conversion, thus providing a reasonable explanation for the unsuccessful EBW heating experiments.

  13. 94 GHz power amplifier MMIC development in state of the art MHEMT and AlGaN/GaN technology

    NARCIS (Netherlands)

    Heijningen, M. van; Bent, G. van der; Rodenburg, M.; Vliet, F.E. van; Quay, R.; Brückner, P.; Schwantuschke, D.; Jukkala, P.; Narhi, T.

    2012-01-01

    Solid-state power amplifiers at W-band (75 - 110 GHz) are attractive for the generation of local-oscillator (LO) power for super-heterodyne receivers operating at sub-millimetre wave frequencies, as needed for example in future space instruments for Earth observation. Apart from space applications

  14. A low power 2.4 GHz transceiver for ZigBee applications

    International Nuclear Information System (INIS)

    Liu Weiyang; Chen Jingjing; Wang Haiyong; Wu Nanjian

    2013-01-01

    This paper presents a low power 2.4 GHz transceiver for ZigBee applications. This transceiver adopts low power system architecture with a low-IF receiver and a direct-conversion transmitter. The receiver consists of a new low noise amplifier (LNA) with a noise cancellation function, a new inverter-based variable gain complex filter (VGCF) for image rejection, a passive quadrature mixer, and a decibel linear programmable gain amplifier (PGA). The transmitter adopts a quadrature mixer and a class-B mode variable gain power amplifier (PA) to reduce power consumption. This transceiver is implemented in 0.18 μm CMOS technology. The receiver achieves −95 dBm of sensitivity, 28 dBc of image rejection, and −8 dBm of third-order input intercept point (IIP3). The transmitter can deliver a maximum of +3 dBm output power with PA efficiency of 30%. The whole chip area is less than 4.32 mm 2 . It only consumes 12.63 mW in receiving mode and 14.22 mW in transmitting mode, respectively. (semiconductor integrated circuits)

  15. Linearizing of Low Noise Power Amplifier Using 5.8GHz Double Loop Feedforward Linearization Technique

    Directory of Open Access Journals (Sweden)

    Abdulkareem Mokif Obais

    2017-05-01

    Full Text Available In this paper, a double loop feedforward linearization technique is analyzed and built with a MMIC low noise amplifier “HMC753” as main amplifier and a two-stage class-A power amplifier as error amplifier. The system is operated with 5V DC supply at a center frequency of 5.8GHz and a bandwidth of 500MHz. The proposed technique, increases the linearity of the MMIC amplifier from 18dBm at 1dB compression point to more than 26dBm. In addition, the proposed system is tested with OFDM signal and it reveals good response in maximizing the linearity region and eliminating distortions. The proposed system is designed and simulated onAdvanced Wave Research-Microwave Office (AWR-MWO.

  16. 10 GHz frequency comb spectral broadening in AlGaAs-on-Insulator nano-waveguide with ultra-low pump power

    DEFF Research Database (Denmark)

    Hu, Hao; Pu, Minhao; Yvind, Kresten

    2017-01-01

    We experimentally demonstrated 10 GHz frequency comb spectral broadening with a 30-dB bandwidth of 238 nm in an 11-mm long AlGaAsOI nano-waveguide. The 10-GHz 230-fs pump pulse has an average power of only 12 mW.......We experimentally demonstrated 10 GHz frequency comb spectral broadening with a 30-dB bandwidth of 238 nm in an 11-mm long AlGaAsOI nano-waveguide. The 10-GHz 230-fs pump pulse has an average power of only 12 mW....

  17. Mixed-signal 0.18μm CMOS and SiGe BiCMOS foundry technologies for ROIC applications

    Science.gov (United States)

    Kar-Roy, Arjun; Howard, David; Racanelli, Marco; Scott, Mike; Hurwitz, Paul; Zwingman, Robert; Chaudhry, Samir; Jordan, Scott

    2010-10-01

    Today's readout integrated-circuits (ROICs) require a high level of integration of high performance analog and low power digital logic. TowerJazz offers a commercial 0.18μm CMOS technology platform for mixed-signal, RF, and high performance analog applications which can be used for ROIC applications. The commercial CA18HD dual gate oxide 1.8V/3.3V and CA18HA dual gate oxide 1.8V/5V RF/mixed signal processes, consisting of six layers of metallization, have high density stacked linear MIM capacitors, high-value resistors, triple-well isolation and thick top aluminum metal. The CA18HA process also has scalable drain extended LDMOS devices, up to 40V Vds, for high-voltage sensor applications, and high-performance bipolars for low noise requirements in ROICs. Also discussed are the available features of the commercial SBC18 SiGe BiCMOS platform with SiGe NPNs operating up to 200/200GHz (fT/fMAX frequencies in manufacturing and demonstrated to 270 GHz fT, for reduced noise and integrated RF capabilities which could be used in ROICs. Implementation of these technologies in a thick film SOI process for integrated RF switch and power management and the availability of high fT vertical PNPs to enable complementary BiCMOS (CBiCMOS), for RF enabled ROICs, are also described in this paper.

  18. 3-D printed 2.4 GHz rectifying antenna for wireless power transfer applications

    Science.gov (United States)

    Skinner, Matthew

    In this work, a 3D printed rectifying antenna that operates at the 2.4GHz WiFi band was designed and manufactured. The printed material did not have the same properties of bulk material, so the printed materials needed to be characterized. The antenna and rectifying circuit was printed out of Acrylonitrile Butadiene Styrene (ABS) filament and a conductive silver paste, with electrical components integrated into the circuit. Before printing the full rectifying antenna, each component was printed and evaluated. The printed antenna operated at the desired frequency with a return loss of -16 dBm with a bandwidth of 70MHz. The radiation pattern was measured in an anechoic chamber with good matching to the model. The rectifying circuit was designed in Ansys Circuit Simulation using Schottky diodes to enable the circuit to operate at lower input power levels. Two rectifying circuits were manufactured, one by printing the conductive traces with silver ink, and one with traces made from copper. The printed silver ink is less conductive than the bulk copper and therefore the output voltage of the printed rectifier was lower than the copper circuit. The copper circuit had an efficiency of 60% at 0dBm and the printed silver circuit had an efficiency of 28.6% at 0dBm. The antenna and rectifying circuits were then connected to each other and the performance was compared to a fully printed integrated rectifying antenna. The rectifying antennas were placed in front of a horn antenna while changing the power levels at the antenna. The efficiency of the whole system was lower than the individual components but an efficiency of 11% at 10dBm was measured.

  19. High linearity 5.2-GHz power amplifier MMIC using CPW structure technology with a linearizer circuit

    International Nuclear Information System (INIS)

    Wu Chiasong; Lin Tah-Yeong; Wu Hsien-Ming

    2010-01-01

    A built-in linearizer was applied to improve the linearity in a 5.2-GHz power amplifier microwave monolithic integrated circuit (MMIC), which was undertaken with 0.15-μm AlGaAs/InGaAs D-mode PHEMT technology. The power amplifier (PA) was studied taking into account the linearizer circuit and the coplanar waveguide (CPW) structures. Based on these technologies, the power amplifier, which has a chip size of 1.44 x 1.10 mm 2 , obtained an output power of 13.3 dBm and a power gain of 14 dB in the saturation region. An input third-order intercept point (HP 3 ) of -3 dBm, an output third-order intercept point (OIP 3 ) of 21.1 dBm and a power added efficiency (PAE) of 22% were attained, respectively. Finally, the overall power characterization exhibited high gain and high linearity, which illustrates that the power amplifier has a compact circuit size and exhibits favorable RF characteristics. This power circuit demonstrated high RF characterization and could be used for microwave power circuit applications at 5.2 GHz. (semiconductor integrated circuits)

  20. Multi-gigabit wireless data transfer at 60 GHz

    International Nuclear Information System (INIS)

    Soltveit, H K; Schöning, A; Wiedner, D; Brenner, R

    2012-01-01

    In this paper we describe the status of the first prototype of the 60 GHz wireless Multi-gigabit data transfer topology currently under development at University of Heidelberg using IBM 130 nm SiGe HBT BiCMOS technology. The 60 GHz band is very suitable for high data rate and short distance applications. One application can be a wireless multi Gbps radial data transmission inside the ATLAS silicon strip detector, making a first level track trigger feasible. The wireless transceiver consists of a transmitter and a receiver. The transmitter includes an On-Off Keying (OOK) modulator, a Local Oscillator (LO), a Power Amplifier (PA) and a Band-pass Filter (BPF). The receiver part is composed of a Band-pass Filter (BPF), a Low Noise Amplifier (LNA), a double balanced down-convert Gilbert mixer, a Local Oscillator (LO), then a BPF to remove the mixer introduced noise, an Intermediate Amplifier (IF), an On-Off Keying demodulator and a limiting amplifier. The first prototype would be able to handle a data-rate of about 3.5 Gbps over a link distance of 1 m. The first simulations of the LNA show that a Noise figure (NF) of 5 dB, a power gain of 21 dB at 60 GHz with a 3 dB bandwidth of more than 20 GHz with a power consumption 11 mW are achieved. Simulations of the PA show an output referred compression point P1dB of 19.7 dB at 60 GHz.

  1. RF-MEMS for future mobile applications: experimental verification of a reconfigurable 8-bit power attenuator up to 110 GHz

    International Nuclear Information System (INIS)

    Iannacci, J; Tschoban, C

    2017-01-01

    RF-MEMS technology is proposed as a key enabling solution for realising the high-performance and highly reconfigurable passive components that future communication standards will demand. In this work, we present, test and discuss a novel design concept for an 8-bit reconfigurable power attenuator, manufactured using the RF-MEMS technology available at the CMM-FBK, in Italy. The device features electrostatically controlled MEMS ohmic switches in order to select/deselect the resistive loads (both in series and shunt configuration) that attenuate the RF signal, and comprises eight cascaded stages (i.e. 8-bit), thus implementing 256 different network configurations. The fabricated samples are measured (S-parameters) from 10 MHz to 110 GHz in a wide range of different configurations, and modelled/simulated with Ansys HFSS. The device exhibits attenuation levels (S21) in the range from  −10 dB to  −60 dB, up to 110 GHz. In particular, S21 shows flatness from 15 dB down to 3–5 dB and from 10 MHz to 50 GHz, as well as fewer linear traces up to 110 GHz. A comprehensive discussion is developed regarding the voltage standing wave ratio, which is employed as a quality indicator for the attenuation levels. The margins of improvement at design level which are needed to overcome the limitations of the presented RF-MEMS device are also discussed. (paper)

  2. Four-to-one power combiner for 20 GHz phased array antenna using RADC MMIC phase shifters

    Science.gov (United States)

    1991-01-01

    The design and microwave simulation of two-to-one microstrip power combiners is described. The power combiners were designed for use in a four element phase array receive antenna subarray at 20 GHz. Four test circuits are described which were designed to enable testing of the power combiner and the four element phased array antenna. Test Circuit 1 enables measurement of the two-to-one power combiner. Test Circuit 2 enables measurement of the four-to-one power combiner. Test Circuit 3 enables measurement of a four element antenna array without phase shifting MMIC's in order to characterize the power combiner with the antenna patch-to-microstrip coaxial feedthroughs. Test circuit 4 is the four element phased array antenna including the RADC MMIC phase shifters and appropriate interconnects to provide bias voltages and control phase bits.

  3. Heavy Ion Microbeam- and Broadbeam-Induced Transients in SiGe HBTs

    Science.gov (United States)

    Pellish, Jonathan A.; Reed, Robert A.; McMorrow, Dale; Vizkelethy, Gyorgy; Ferlet-Cavrois, Veronique; Baggio, Jacques; Duhamel, Olivier; Moen, Kurt A.; Phillips, Stanley D.; Diestelhorst, Ryan M.; hide

    2009-01-01

    SiGe HBT heavy ion-induced current transients are measured using Sandia National Laboratories microbeam and high- and low-energy broadbeam sources at the Grand Accelerateur National d'Ions Lourds and the University of Jyvaskyla. The data were captured using a custom broadband IC package and real-time digital phosphor oscilloscopes with at least 16 GHz of analog bandwidth. These data provide detailed insight into the effects of ion strike location, range, and LET.

  4. Free electron laser with small period wiggler and sheet electron beam: A study of the feasibility of operation at 300 GHz with 1 MW CW output power

    International Nuclear Information System (INIS)

    Booske, J.H.; Granatstein, V.L.; Antonsen, T.M. Jr.

    1988-01-01

    The use of a small period wiggler (/ell//sub ω/ 2 ). Based on these encouraging results, a proof-of-principle experiment is being assembled, and is aimed at demonstrating FEL operating at 120 GHz with 300 kW output power in 1 μs pulses: electron energy would be 410 keV. Preliminary design of a 300 GHz 1 MW FEL with an untapered wiggler is also presented. 10 refs., 5 figs., 3 tabs

  5. Broadband rectangular TEn0 mode exciter with H-plane power dividers for 100 GHz confocal gyro-devices.

    Science.gov (United States)

    Yao, Yelei; Wang, Jianxun; Li, Hao; Liu, Guo; Luo, Yong

    2017-07-01

    A generic approach to excite TE n0 (n ≥ 1) modes in a rectangular waveguide for confocal gyro-devices is proposed. The exciter consists of a 3 dB H-plane power divider (n ≥ 3) and a mode-converting section. The injection power is split into two in-phase signals with equal amplitudes which simultaneously excite the secondary waveguide via two sets of multiple slots. Both the position and width of the slot are symmetrically distributed with respect to the center line for each set of slots. The slot width complies with a geometry sequence, with adjacent slots being spaced a quarter wavelength apart to cancel the backward wave out. A TE 40 mode exciter at 100 GHz is numerically simulated and optimized, achieving a 1 dB and a 3 dB transmission bandwidth of 18.2 and 21 GHz, respectively. The prototype is fabricated and measured. The cold test is carried out utilizing two identical back-to-back connected mode exciters, and the measured performances are in good agreement with the numerical simulation results when taking into account the wall loss and assembly tolerance.

  6. SiGe HBT linear-in-dB high dynamic range RF envelope detectors and wideband high linearity amplifiers

    OpenAIRE

    Pan, Hsuan-yu

    2010-01-01

    This research work aims on exploiting SiGe HBT technologies in high dynamic range wideband RF linear-in- dB envelope detectors and linear amplifiers. First, an improved all-npn broadband highly linear SiGe HBT differential amplifier is presented based on a variation of Caprio's Quad. A broadband linear amplifier with 46dBm OIP₃ at 20MHz, 34dBm OIP₃ at 1GHz, 6dB noise figure and 10.3dBm P₁dB is demonstrated. Second, an improved exact dynamic model of a fast-settling linear-in-dB Automatic Gain...

  7. A low-power 802.11 AD compatible 60-GHz phase-locked loop in 65-NM CMOS

    KAUST Repository

    Cheema, Hammad M.; Arsalan, Muhammad; Salama, Khaled N.; Shamim, Atif

    2015-01-01

    A 60-GHz fundamental frequency phase locked loop (PLL) as part of a highly integrated system-on-chip transmitter with onchip memory and antenna is presented. As a result of localized optimization approach for each component, the PLL core components only consume 30.2 mW from a 1.2 V supply. A systematic design procedure to achieve high phase margin and wide locking range is presented. The reduction of parasitic and fixed capacitance contributions in the voltage controlled oscillator enables the coverage of the complete 802.11 ad frequency band from 57.2 to 65.8 GHz. A new 4-stage distribution network supplying the local oscillator (LO) signal to the mixer, the feedback loop and the external equipment is introduced. The prescaler based on the static frequency division approach is enhanced using shunt-peaking and asymmetric capacitive loading. The current mode logic based divider chain is optimized for low power and minimum silicon foot-print. A dead-zone free phase frequency detector, low leakage charge pump, and an integrated second-order passive filter completes the feedback loop. The PLL implemented in 65 nm CMOS process occupies only 0.6 mm2 of chip space and has a measured locking range from 56.8 to 66.5 GHz. The reference spurs are lower than -40 dBc and the in-band and out-of-band phase noise is -88.12 dBc/Hz and -117 dBc/Hz, respectively.

  8. A low-power 802.11 AD compatible 60-GHz phase-locked loop in 65-NM CMOS

    KAUST Repository

    Cheema, Hammad M.

    2015-01-23

    A 60-GHz fundamental frequency phase locked loop (PLL) as part of a highly integrated system-on-chip transmitter with onchip memory and antenna is presented. As a result of localized optimization approach for each component, the PLL core components only consume 30.2 mW from a 1.2 V supply. A systematic design procedure to achieve high phase margin and wide locking range is presented. The reduction of parasitic and fixed capacitance contributions in the voltage controlled oscillator enables the coverage of the complete 802.11 ad frequency band from 57.2 to 65.8 GHz. A new 4-stage distribution network supplying the local oscillator (LO) signal to the mixer, the feedback loop and the external equipment is introduced. The prescaler based on the static frequency division approach is enhanced using shunt-peaking and asymmetric capacitive loading. The current mode logic based divider chain is optimized for low power and minimum silicon foot-print. A dead-zone free phase frequency detector, low leakage charge pump, and an integrated second-order passive filter completes the feedback loop. The PLL implemented in 65 nm CMOS process occupies only 0.6 mm2 of chip space and has a measured locking range from 56.8 to 66.5 GHz. The reference spurs are lower than -40 dBc and the in-band and out-of-band phase noise is -88.12 dBc/Hz and -117 dBc/Hz, respectively.

  9. A Low Power 2.4 GHz CMOS Mixer Using Forward Body Bias Technique for Wireless Sensor Network

    Science.gov (United States)

    Yin, C. J.; Murad, S. A. Z.; Harun, A.; Ramli, M. M.; Zulkifli, T. Z. A.; Karim, J.

    2018-03-01

    Wireless sensor network (WSN) is a highly-demanded application since the evolution of wireless generation which is often used in recent communication technology. A radio frequency (RF) transceiver in WSN should have a low power consumption to support long operating times of mobile devices. A down-conversion mixer is responsible for frequency translation in a receiver. By operating a down-conversion mixer at a low supply voltage, the power consumed by WSN receiver can be greatly reduced. This paper presents a development of low power CMOS mixer using forward body bias technique for wireless sensor network. The proposed mixer is implemented using CMOS 0.13 μm Silterra technology. The forward body bias technique is adopted to obtain low power consumption. The simulation results indicate that a low power consumption of 0.91 mW is achieved at 1.6 V supply voltage. Moreover, the conversion gain (CG) of 21.83 dB, the noise figure (NF) of 16.51 dB and the input-referred third-order intercept point (IIP3) of 8.0 dB at 2.4 GHz are obtained. The proposed mixer is suitable for wireless sensor network.

  10. High-Power Plasma Switch for 11.4 GHz Microwave Pulse Compressor

    International Nuclear Information System (INIS)

    Hirshfield, Jay L.

    2010-01-01

    Results obtained in several experiments on active RF pulse compression at X-band using a magnicon as the high-power RF source are presented. In these experiments, microwave energy was stored in high-Q TE01 and TE02 modes of two parallel-fed resonators, and then discharged using switches activated with rapidly fired plasma discharge tubes. Designs and high-power tests of several versions of the compressor are described. In these experiments, coherent pulse superposition was demonstrated at a 5-9 MW level of incident power. The compressed pulses observed had powers of 50-70 MW and durations of 40-70 ns. Peak power gains were measured to be in the range of 7:1-11:1 with efficiency in the range of 50-63%.

  11. Ultra-broadband Nonlinear Microwave Monolithic Integrated Circuits in SiGe, GaAs and InP

    DEFF Research Database (Denmark)

    Krozer, Viktor; Johansen, Tom Keinicke; Djurhuus, Torsten

    2006-01-01

    .5 GHz and ≫ 10 GHz for SiGe BiCMOS and GaAs MMIC, respectively. Analysis of the frequency behaviour of frequency converting devices is presented for improved mixer design. Millimeter-wave front-end components for advanced microwave imaging and communications purposes have also been demonstrated......Analog MMIC circuits with ultra-wideband operation are discussed in view of their frequency limitation and different circuit topologies. Results for designed and fabricated frequency converters in SiGe, GaAs, and InP technologies are presented in the paper. RF type circuit topologies exhibit a flat...... conversion gain with a 3 dB bandwidth of 10 GHz for SiGe and in excess of 20 GHz for GaAs processes. The concurrent LO-IF isolation is better than -25 dB, without including the improvement due to the combiner circuit. The converter circuits exhibit similar instantaneous bandwidth at IF and RF ports of ≫ 7...

  12. Design of 340 GHz 2× and 4× Sub-Harmonic Mixers Using Schottky Barrier Diodes in Silicon-Based Technology

    Directory of Open Access Journals (Sweden)

    Chao Liu

    2015-05-01

    Full Text Available This paper presents the design of terahertz 2× and 4× sub-harmonic down-mixers using Schottky Barrier Diodes fabricated in standard 0.13 μm SiGe BiCMOS technology. The 340 GHz sub-harmonic mixers (SHMs are designed based on anti-parallel-diode-pairs (APDPs. With the 2nd and 4th harmonic, local oscillator (LO frequencies of 170 GHz and 85 GHz are used to pump the two 340 GHz SHMs. With LO power of 7 dBm, the 2× SHM exhibits a conversion loss of 34.5–37 dB in the lower band (320–340 GHz and 35.5–41 dB in the upper band (340–360 GHz; with LO power of 9 dBm, the 4× SHM exhibits a conversion loss of 39–43 dB in the lower band (320–340 GHz and 40–48 dB in the upper band (340–360 GHz. The measured input 1-dB conversion gain compression point for the 2× and 4× SHMs are −8 dBm and −10 dBm at 325 GHz, respectively. The simulated LO-IF (intermediate frequency isolation of the 2× SHM is 21.5 dB, and the measured LO-IF isolation of the 4× SHM is 32 dB. The chip areas of the 2× and 4× SHMs are 330 μm × 580 μm and 550 μm × 610 μm, respectively, including the testing pads.

  13. An Optimized 2.4GHz RF Power Amplifier Performance for WLAN System

    International Nuclear Information System (INIS)

    Ali, Mohammed H; Chakrabarty, C K; Hock, Goh C; Abdalla, Ahmed N

    2013-01-01

    Recently, the design of RF power amplifiers (PAs) for modern wireless systems are faced with a difficult tradeoff for example, cellphone; battery lifetime is largely determined by the power efficiency of the PA and high spectral efficiency which have ability to transmit data at the highest possible rate for a given channel bandwidth. This paper presents the design a multi stage class AB power Amplifier with high power added efficiency (PAE) and acceptable linearity for the WLAN applications. The open-circuited third harmonic control circuit enhances the efficiency of the PA without deteriorating the linearity of class-AB mode of the PA. The voltage and current waveforms are simulated to evaluate the appropriate operation for the modes. The effectiveness of the proposed controller has been verified by comparing proposed method with another methods using simulation study under a variety of conditions. The proposed circuit operation for a WLAN signals delivers a power-added efficiency (PAE) of 37.6% is measured at 31.6-dBm output power while dissipating 34.61 mA from a 1.8V supply. Finally, the proposed PA is show a good and acceptable result for the WLAN system.

  14. An Optimized 2.4GHz RF Power Amplifier Performance for WLAN System

    Science.gov (United States)

    Ali, Mohammed H.; Chakrabarty, C. K.; Abdalla, Ahmed N.; Hock, Goh C.

    2013-06-01

    Recently, the design of RF power amplifiers (PAs) for modern wireless systems are faced with a difficult tradeoff for example, cellphone; battery lifetime is largely determined by the power efficiency of the PA and high spectral efficiency which have ability to transmit data at the highest possible rate for a given channel bandwidth. This paper presents the design a multi stage class AB power Amplifier with high power added efficiency (PAE) and acceptable linearity for the WLAN applications. The open-circuited third harmonic control circuit enhances the efficiency of the PA without deteriorating the linearity of class-AB mode of the PA. The voltage and current waveforms are simulated to evaluate the appropriate operation for the modes. The effectiveness of the proposed controller has been verified by comparing proposed method with another methods using simulation study under a variety of conditions. The proposed circuit operation for a WLAN signals delivers a power-added efficiency (PAE) of 37.6% is measured at 31.6-dBm output power while dissipating 34.61 mA from a 1.8V supply. Finally, the proposed PA is show a good and acceptable result for the WLAN system.

  15. A 1–2 GHz high linearity transformer-feedback power-to-current LNA

    NARCIS (Netherlands)

    Li, X.; Serdijn, W.A.; Woestenburg, B.E.M.; Bij de Vaate, J.G.

    2009-01-01

    This paper demonstrates that a double-loop transformer-feedback power-to-current low noise amplifier, to be implemented in a 0.2 lm GaAs p-HEMT IC process, is able to obtain a noise figure less than 0.8 dB, an input return loss less than -12 dB, a flat voltage-to-current signal transfer of 180 mS,

  16. Fast power measurement on a 30 GHz/15 kW gyrotron

    International Nuclear Information System (INIS)

    Saala, G.

    2004-09-01

    This work has been developed in the scope of a study-thesis at the Universitaet Karlsruhe (TH). The realization took place at the Institut fuer Hochleistungsimpuls- und Mikrowellentechnik (IHM) at the Forschungszentrum Karlsruhe (FZK). The aim was to investigate the possibilities of a fast power measurement at a compact, industrial gyrotron-system. To measure the output-power a small fraction of the gyrotron microwave radiation is coupled out and analyzed using a diode-detector. At the beginning of the work a mirror of the quasi-optical transmission line with a built in λ/4-coupler was available. This built-in coupler and other coupling structures which have been set up during this work have been characterized. To be able to perform reproduceable measurements several computer programs have been developed. Using these programs the gyrotron-system can be remote-controlled from a PC. The diode-detector signal has been analyzed under different conditions of gyrotron operation with respect to its short-term- and long-term-stability. After that the dependency of the calorimetrically measured output-power of the gyrotron has been used to calibrate the diode-voltage. (orig.)

  17. The Atacama Cosmology Telescope: A Measurement of the Cosmic Microwave Background Power Spectrum at 148 AND 218 GHz from the 2008 Southern Survey

    Science.gov (United States)

    Das, Sudeep; Marriage, Tobias A.; Ade, Peter A. R.; Aguirre, Paula; Amiri, Mandana; Appel, John W.; Barrientos, L. Felipe; Battistelli, Elia A.; Bond, J. Richard; Brown, Ben; hide

    2010-01-01

    We present measurements of the cosmic microwave background (CMB) power spectrum made by the Atacama Cosmology Telescope at 148 GHz and 218 GHz, as well as the cross-frequency spectrum between the two channels. Our results dearly show the second through the seventh acoustic peaks in the CMB power spectrum. The measurements of these higher-order peaks provide an additional test of the ACDM cosmological model. At l > 3000, we detect power in excess of the primary anisotropy spectrum of the CMB. At lower multipoles 500 < l < 3000, we find evidence for gravitational lensing of the CMB in the power spectrum at the 2.8(sigma) level. We also detect a low level of Galactic dust in our maps, which demonstrates that we can recover known faint, diffuse signals.

  18. Fabrication of Very High Efficiency 5.8 GHz Power Amplifiers using AlGaN HFETs on SiC Substrates for Wireless Power Transmission

    Science.gov (United States)

    Sullivan, Gerry

    2001-01-01

    For wireless power transmission using microwave energy, very efficient conversion of the DC power into microwave power is extremely important. Class E amplifiers have the attractive feature that they can, in theory, be 100% efficient at converting, DC power to RF power. Aluminum gallium nitride (AlGaN) semiconductor material has many advantageous properties, relative to silicon (Si), gallium arsenide (GaAs), and silicon carbide (SiC), such as a much larger bandgap, and the ability to form AlGaN/GaN heterojunctions. The large bandgap of AlGaN also allows for device operation at higher temperatures than could be tolerated by a smaller bandgap transistor. This could reduce the cooling requirements. While it is unlikely that the AlGaN transistors in a 5.8 GHz class E amplifier can operate efficiently at temperatures in excess of 300 or 400 C, AlGaN based amplifiers could operate at temperatures that are higher than a GaAs or Si based amplifier could tolerate. Under this program, AlGaN microwave power HFETs have been fabricated and characterized. Hybrid class E amplifiers were designed and modeled. Unfortunately, within the time frame of this program, good quality HFETs were not available from either the RSC laboratories or commercially, and so the class E amplifiers were not constructed.

  19. Design of 0.8–2.7 GHz High Power Class-F Harmonic-Tuned Power Amplifier with Parasitic Compensation Circuit

    Directory of Open Access Journals (Sweden)

    Zhiqun Cheng

    2017-01-01

    Full Text Available The design, implementation, and measurements of a high efficiency and high power wideband GaN HEMT power amplifier are presented. Package parasitic effect is reduced significantly by a novel compensation circuit design to improve the accuracy of impedance matching. An improved structure is proposed based on the traditional Class-F structure with all even harmonics and the third harmonic effectively controlled, respectively. Also the stepped-impedance matching method is applied to the third harmonic control network, which has a positive effect on the expansion bandwidth. CGH40025F power transistor is utilized to build the power amplifier working at 0.8 to 2.7 GHz, with the measured saturated output power 20–50 W, drain efficiency 52%–76%, and gain level above 10 dB. The second and the third harmonic suppression levels are maintained at −16 to −36 dBc and −16 to −33 dBc, respectively. The simulation and the measurement results of the proposed power amplifier show good consistency.

  20. An RF-to-DC energy harvester for co-integration in a low-power 2.4 GHz transceiver frontend

    NARCIS (Netherlands)

    Masuch, J.; Delgado-Restituto, M.; Milosevic, D.; Baltus, P.G.M.

    2012-01-01

    A 2.4 GHz energy harvester for co-integration into a low-power transceiver (TRx) operating at the same frequency is presented. An RF switch decouples the harvester from the TRx and keeps the performance degradation of the TRx low, i.e. 0.2 dB reduced output power in Tx-mode and 0.4 dB reduced

  1. Human speech articulator measurements using low power, 2GHz Homodyne sensors

    International Nuclear Information System (INIS)

    Barnes, T; Burnett, G C; Holzrichter, J F

    1999-01-01

    Very low power, short-range microwave ''radar-like'' sensors can measure the motions and vibrations of internal human speech articulators as speech is produced. In these animate (and also in inanimate acoustic systems) microwave sensors can measure vibration information associated with excitation sources and other interfaces. These data, together with the corresponding acoustic data, enable the calculation of system transfer functions. This information appears to be useful for a surprisingly wide range of applications such as speech coding and recognition, speaker or object identification, speech and musical instrument synthesis, noise cancellation, and other applications

  2. Human speech articulator measurements using low power, 2GHz Homodyne sensors

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, T; Burnett, G C; Holzrichter, J F

    1999-06-29

    Very low power, short-range microwave ''radar-like'' sensors can measure the motions and vibrations of internal human speech articulators as speech is produced. In these animate (and also in inanimate acoustic systems) microwave sensors can measure vibration information associated with excitation sources and other interfaces. These data, together with the corresponding acoustic data, enable the calculation of system transfer functions. This information appears to be useful for a surprisingly wide range of applications such as speech coding and recognition, speaker or object identification, speech and musical instrument synthesis, noise cancellation, and other applications.

  3. RF link for Implanted Medical Devices (IMDs) and Sub-GHz Inductive Power Transmission

    OpenAIRE

    Diet , Antoine; Koulouridis , Satvros; Le Bihan , Yann; Luu , Quang-Trung; Meyer , Olivier; Pichon , Lionel; Biancheri-Astier , Marc

    2017-01-01

    International audience; Ce travail s'inscrit dan sune etude exploratoire sur les possibilités de télé-alimentation RF des implants médicaux et/ou de communication entre eux. En effet, la durée de fonctionnement de certains implants avec batterie rend leur utilisation critique car il ne faut pas privilégier une intervention chirurgicale lourde s'il est possible d'agir de manière non-invasive. La transmission d'énergie sans fil ou WPT (Wireless Power Transfer) est au cœur de nombreuses autres t...

  4. Design of low power common-gate low noise amplifier for 2.4 GHz wireless sensor network applications

    International Nuclear Information System (INIS)

    Zhang Meng; Li Zhiqun

    2012-01-01

    This paper presents a differential low power low noise amplifier designed for the wireless sensor network (WSN) in a TSMC 0.18 μm RF CMOS process. A two-stage cross-coupling cascaded common-gate (CG) topology has been designed as the amplifier. The first stage is a capacitive cross-coupling topology. It can reduce the power and noise simultaneously. The second stage is a positive feedback cross-coupling topology, used to set up a negative resistance to enhance the equivalent Q factor of the inductor at the load to improve the gain of the LNA. A differential inductor has been designed as the load to achieve reasonable gain. This inductor has been simulated by the means of momentum electromagnetic simulation in ADS. A 'π' circuit model has been built as the inductor model by iteration in ADS. The inductor has been fabricated separately to verify the model. The LNA has been fabricated and measured. The LNA works well centered at 2.44 GHz. The measured gain S 21 is variable with high gain at 16.8 dB and low gain at 1 dB. The NF (noise figure) at high gain mode is 3.6 dB, the input referenced 1 dB compression point (IP1dB) is about −8 dBm and the IIP3 is 2 dBm at low gain mode. The LNA consumes about 1.2 mA current from 1.8 V power supply.

  5. Power-Combined GaN Amplifier with 2.28-W Output Power at 87 GHz

    Science.gov (United States)

    Fung, King Man; Ward, John; Chattopadhyay, Goutam; Lin, Robert H.; Samoska, Lorene A.; Kangaslahti, Pekka P.; Mehdi, Imran; Lambrigtsen, Bjorn H.; Goldsmith, Paul F.; Soria, Mary M.; hide

    2011-01-01

    Future remote sensing instruments will require focal plane spectrometer arrays with higher resolution at high frequencies. One of the major components of spectrometers are the local oscillator (LO) signal sources that are used to drive mixers to down-convert received radio-frequency (RF) signals to intermediate frequencies (IFs) for analysis. By advancing LO technology through increasing output power and efficiency, and reducing component size, these advances will improve performance and simplify architecture of spectrometer array systems. W-band power amplifiers (PAs) are an essential element of current frequency-multiplied submillimeter-wave LO signal sources. This work utilizes GaN monolithic millimeter-wave integrated circuit (MMIC) PAs developed from a new HRL Laboratories LLC 0.15- m gate length GaN semiconductor transistor. By additionally waveguide power combining PA MMIC modules, the researchers here target the highest output power performance and efficiency in the smallest volume achievable for W-band.

  6. SiGe BiCMOS manufacturing platform for mmWave applications

    Science.gov (United States)

    Kar-Roy, Arjun; Howard, David; Preisler, Edward; Racanelli, Marco; Chaudhry, Samir; Blaschke, Volker

    2010-10-01

    TowerJazz offers high volume manufacturable commercial SiGe BiCMOS technology platforms to address the mmWave market. In this paper, first, the SiGe BiCMOS process technology platforms such as SBC18 and SBC13 are described. These manufacturing platforms integrate 200 GHz fT/fMAX SiGe NPN with deep trench isolation into 0.18μm and 0.13μm node CMOS processes along with high density 5.6fF/μm2 stacked MIM capacitors, high value polysilicon resistors, high-Q metal resistors, lateral PNP transistors, and triple well isolation using deep n-well for mixed-signal integration, and, multiple varactors and compact high-Q inductors for RF needs. Second, design enablement tools that maximize performance and lowers costs and time to market such as scalable PSP and HICUM models, statistical and Xsigma models, reliability modeling tools, process control model tools, inductor toolbox and transmission line models are described. Finally, demonstrations in silicon for mmWave applications in the areas of optical networking, mobile broadband, phased array radar, collision avoidance radar and W-band imaging are listed.

  7. Components for transmission of very high power mm-waves (200 kW at 28, 70 and 140 GHz) in overmoded circular waveguides

    International Nuclear Information System (INIS)

    Thumm, M.; Erckmann, V.; Kasparek, W.; Kumric, H.; Mueller, G.A.; Schueller, P.G.; Wilhelm, R.

    1986-03-01

    Optimized overmoded circular waveguide components of transmission lines developed for high-power (200 kW) millimeter wave applications at 28, 70 and 140 GHz, as e.g. electron cyclotron resonance heating (ECRH) of plasmas for thermonuclear fusion research with gyrotrons, are described. Axisymmetric, narrow, pencil-like beams with well-defined polarization (HE11 hybrid mode) are used at open-ended corrugated waveguide antennas. The HE11 mode is generated from TEsub(On) gyrotron modes by the two multi-step mode conversion processes: (1) TEsub(On)->TE 01 ->TE 11 ->HE 11 or (2) TEsub(On)->TE 01 ->TM 11 ->HE 11 . This paper reports computer-aided analyses and measurements on mode transducer systems of the first type at 28 and 70 GHz and of the second type at 140 GHz. In all cases the overall efficiency of the complete mode conversion sequence in the desired mode is approximately (92-95)%. The mode purity in the transmission lines is conserved by using corrugated gradual waveguide bends with optimized curvature distribution and diameter tapers with non-linear contours. Highly efficient corrugated-wall mode selective filters decouple the different waveguide sections. Mode content and reflected power are determined by a novel device (k-spectrometer). Absolute power calibration is done with newly developed calorimetric loads using an organic absorbing fluid. (orig.) [de

  8. Circuit design and simulation of a HV-supply controlling the power of 140 GHz 1 MW gyrotrons for ECRH on W7-X

    International Nuclear Information System (INIS)

    Brand, P.; Mueller, G.A.

    2003-01-01

    For plasma heating by ECR in the Stellarator W7-X under construction, 140 GHz gyrotrons with 1 MW cw output power are under development. These tubes have a voltage depressed collector for electron energy recovery. Each gyrotron is fed by two high-voltage sources: a high-power supply for driving the electron beam and a precision low-power supply for beam acceleration. In addition, a protection system with a thyratron crowbar for fast power removal in case of gyrotron arcing is installed. The low-power high-voltage source for beam acceleration is realized by a high-voltage servo-amplifier driving the depression voltage such that the influence of the voltage noise of the main high-power supply on the acceleration voltage is suppressed by feed-back control of the amplifier. Design and simulation of the servo-amplifier by PSpice is presented

  9. SiGe Based Low Temperature Electronics for Lunar Surface Applications

    Science.gov (United States)

    Mojarradi, Mohammad M.; Kolawa, Elizabeth; Blalock, Benjamin; Cressler, John

    2012-01-01

    The temperature at the permanently shadowed regions of the moon's surface is approximately -240 C. Other areas of the lunar surface experience temperatures that vary between 120 C and -180 C during the day and night respectively. To protect against the large temperature variations of the moon surface, traditional electronics used in lunar robotics systems are placed inside a thermally controlled housing which is bulky, consumes power and adds complexity to the integration and test. SiGe Based electronics have the capability to operate over wide temperature range like that of the lunar surface. Deploying low temperature SiGe electronics in a lander platform can minimize the need for the central thermal protection system and enable the development of a new generation of landers and mobility platforms with highly efficient distributed architecture. For the past five years a team consisting of NASA, university and industry researchers has been examining the low temperature and wide temperature characteristic of SiGe based transistors for developing electronics for wide temperature needs of NASA environments such as the Moon, Titan, Mars and Europa. This presentation reports on the status of the development of wide temperature SiGe based electronics for the landers and lunar surface mobility systems.

  10. Development of 20 kW input power coupler for 1.3 GHz ERL main linac. Component test at 30 kW IOT test stand

    International Nuclear Information System (INIS)

    Sakai, Hiroshi; Umemori, Kensei; Sakanaka, Shogo; Takahashi, Takeshi; Furuya, Takaaki; Shinoe, Kenji; Ishii, Atsushi; Nakamura, Norio; Sawamura, Masaru

    2009-01-01

    We started to develop an input coupler for a 1.3 GHz ERL superconducting cavity. Required input power is about 20 kW for the cavity acceleration field of 20 MV/m and the beam current of 100 mA in energy recovery operation. The input coupler is designed based on the STF-BL input coupler and some modifications are applied to the design for the CW 20 kW power operation. We fabricated input coupler components such as ceramic windows and bellows and carried out the high-power test of the components by using a 30 kW IOT power source and a test stand constructed for the highpower test. In this report, we mainly describe the results of the high-power test of ceramic window and bellows. (author)

  11. A 25 W 70% Efficiency Doherty Power Amplifier at 6 dB Output Back-Off for 2.4 GHz Applications with VGS, PEAK

    Directory of Open Access Journals (Sweden)

    Jorge Moreno Rubio

    2015-01-01

    Full Text Available This paper shows the design and simulation results of a hybrid Doherty power amplifier. The amplifier has been designed at 2,4 GHz, obtaining power-added efficiency above 70 % for 6 dB output power back-off, together with a small signal gain of 17 dB. Design and analysis equations are presented considering class AB bias conditions for the main amplifier and class C for the peak one in back-off larger than 6 dB, and FET device assumption. An additional control on the bias point of the peak device has been carried out, in order to increase the gain on the Doherty region and ease the design of the peak branch. A Cree’s GaN-HEMT CGH40010F device has been used with a nonlinear model guarantied up to 6 GHz and with an expected output power of 10 W. The obtained output power is higher than 25-W. The simulation has been carried out using Agilent ADS CAD tools. The present design could present the state of the art in terms of continuous-wave (CW characterization

  12. Templated self-assembly of SiGe quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Dais, Christian

    2009-08-19

    -dimensional quantum dot crystals. The analyzed SiGe quantum dots have a type II band alignment, with holes confined in the dots and electrons confined in the strained Si in the surrounding of the dots. The recombination energy of these indirect excitons depends on size, Ge content and strain distribution of the quantum dots. It is shown that the structural uniformity of the created quantum dot structures is reflected in their optical properties, resulting in a narrow and stable photoluminescence emission with well separated no-phonon and transversal optical phonon lines. The narrow dot luminescence can be shifted by varying Ge coverage, dot size or dot period. Furthermore excitation-power dependent and temperature dependent photoluminescence measurements are discussed. Band structure calculations indicate that the electronic states of the quantum dot crystals are electronically coupled at least in vertical direction. For the quantum dot crystal with a lateral period of 35 nm even a coupling in all three dimensions is calculated. Thus, the three-dimensional dot arrangement represents not only from the structural but also from the electronic point of view an artificial crystal. (orig.)

  13. Generation of strong electromagnetic power at 35 GHz from the interaction of a resonant cavity with a relativistic electron beam generated by a free electron laser

    International Nuclear Information System (INIS)

    Lefevre, Thibaut

    2000-01-01

    The next generation of electron-positron linear colliders must reach the TeV energy range. For this, one requires an adequate RF power source to feed the accelerating cavities of the collider. One way to generate this source is to use the Two Beam Accelerator concept in which the RF power is produced in resonant cavities driven by an intense bunched beam. In this thesis, I present the experimental results obtained at the CEA/CESTA using an electron beam generated by an induction linac. First, some studies were performed with the LELIA induction linac (2.2 MeV, 1 kA, 80 ns) using a Free Electron Laser (FEL) as a buncher at 35 GHz. A second part relates the experiment made with the PIVAIR induction linac (7 MeV, 1 kA, 80 ns) in order to measure the RF power extracted from a resonant cavity at 35 GHz, which is driven by the bunches produced in the FEL. One can also find a simple theoretical modeling of the beam-cavity interaction, and the numerical results dealing with the design of the cavity we tested. (author) [fr

  14. The MAT/TOCO Measurement of the Angular Power Spectrum of the Cosmic Microwave Background at 30 and 40 GHz

    Science.gov (United States)

    Nolta, M. R.; Devlin, M. J.; Dorwart, W. B.; Miller, A. D.; Page, L. A.; Puchalla, J.; Torbet, E.; Tran, H. T.

    2003-11-01

    We present a measurement of the angular spectrum of the cosmic microwave background from l=26 to 225 from the 30 and 40 GHz channels of the MAT/TOCO experiment based on two seasons of observations. At comparable frequencies, the data extend to a lower l than the recent Very Small Array and DASI results. After accounting for known foreground emission in a self-consistent analysis, a rise from the Sachs-Wolfe plateau to a peak of δTl~80 μK near l~200 is observed.

  15. A 5.2GHz, 0.5mW RF powered wireless sensor with dual on-chip antennas for implantable intraocular pressure monitoring

    KAUST Repository

    Arsalan, Muhammad

    2013-06-01

    For the first time a single chip implantable wireless sensor system for Intraocular Pressure Monitoring (IOPM) is presented. This system-on-chip (SoC) is battery-free and harvests energy from incoming RF signals. The chip is self-contained and does not require external components or bond wires to function. This 1.4mm3 SoC has separate 2.4GHz-transmit and 5.2GHz-receive antennas, an energy harvesting module, a temperature sensor, a 7-bit TIQ Flash ADC, a 4-bit RFID, a power management and control unit, and a VCO transmitter. The chip is fabricated in a standard 6-metal 0.18μm CMOS process and is designed to work with a post-processed MEMS pressure sensor. It consumes 513μW of peak power and when implanted inside the eye, it is designed to communicate with an external reader using on-off keying (OOK). © 2013 IEEE.

  16. A 5.2GHz, 0.5mW RF powered wireless sensor with dual on-chip antennas for implantable intraocular pressure monitoring

    KAUST Repository

    Arsalan, Muhammad; Ouda, Mahmoud H.; Marnat, Loic; Ahmad, Talha Jamal; Shamim, Atif; Salama, Khaled N.

    2013-01-01

    For the first time a single chip implantable wireless sensor system for Intraocular Pressure Monitoring (IOPM) is presented. This system-on-chip (SoC) is battery-free and harvests energy from incoming RF signals. The chip is self-contained and does not require external components or bond wires to function. This 1.4mm3 SoC has separate 2.4GHz-transmit and 5.2GHz-receive antennas, an energy harvesting module, a temperature sensor, a 7-bit TIQ Flash ADC, a 4-bit RFID, a power management and control unit, and a VCO transmitter. The chip is fabricated in a standard 6-metal 0.18μm CMOS process and is designed to work with a post-processed MEMS pressure sensor. It consumes 513μW of peak power and when implanted inside the eye, it is designed to communicate with an external reader using on-off keying (OOK). © 2013 IEEE.

  17. Blood-brain barrier permeation in the rat during exposure to low-power 1.7-GHz microwave radiation

    International Nuclear Information System (INIS)

    Ward, T.R.; Ali, J.S.

    1985-01-01

    The permeability of the blood-brain barrier to high-and low-molecular-weight compounds has been measured as a function of continuous-wave (CW) and pulsed-microwave radiation. Adult rats, anesthetized with pentobarbital and injected intravenously with a mixture of [ 14 C] sucrose and [ 3 H] inulin, were exposed for 30 min at a specific absorption rate of 0.1 W/kg to 1.7-GHz CW and pulsed (0.5-microseconds pulse width, 1,000 pps) microwaves. After exposure, the brain was perfused and sectioned into nine regions, and the radioactivity in each region was counted. During identical exposure conditions, temperatures of rats were measured in eight of the brain regions by a thermistor probe that did not perturb the field. No change in uptake of either tracer was found in any of the eight regions as compared with those of sham-exposed animals

  18. Effect of Synthesis Procedure on Thermoelectric Property of SiGe Alloy

    Science.gov (United States)

    Li, Jing; Han, Jun; Jiang, Tao; Luo, Lili; Xiang, Yongchun

    2018-05-01

    SiGe thermoelectric material has been synthesized by ball milling combined with hot pressing (HP) or spark plasma sintering (SPS). Effects of ball milling time, powder to ball weight ratio and sintering method on microstructure and thermoelectric properties of SiGe are studied. The results show that longer ball milling time leads to decreased density and worse electrical properties. In the sintering process, SPS results in much larger density and better electrical properties than HP. The Si0.795Ge0.2B0.005 sample prepared by 2 h ball milling combined with SPS obtains a maximum power factor of 3.0 mW m-1 K-2 at 860 K and ZT of 0.95 at 1000 K.

  19. A 60-GHz energy harvesting module with on-chip antenna and switch for co-integration with ULP radios in 65-nm CMOS with fully wireless mm-wave power transfer measurement

    NARCIS (Netherlands)

    Gao, H.; Matters - Kammerer, M.; Harpe, P.J.A.; Milosevic, D.; Roermund, van A.H.M.; Linnartz, J.P.M.G.; Baltus, P.G.M.

    2014-01-01

    In this paper the architecture and performance of a co-integrated 60 GHz on-chip wireless energy harvester and ultra-low power (ULP) radio in 65-nm CMOS are discussed. Integration of an on-chip antenna with wireless power receiver and wireless data transfer module is the crucial next step to achieve

  20. Impact of High Power Interference Sources in Planning and Deployment of Wireless Sensor Networks and Devices in the 2.4 GHz Frequency Band in Heterogeneous Environments

    Directory of Open Access Journals (Sweden)

    Francisco Falcone

    2012-11-01

    Full Text Available In this work, the impact of radiofrequency radiation leakage from microwave ovens and its effect on 802.15.4 ZigBee-compliant wireless sensor networks operating in the 2.4 GHz Industrial Scientific Medical (ISM band is analyzed. By means of a novel radioplanning approach, based on electromagnetic field simulation of a microwave oven and determination of equivalent radiation sources applied to an in-house developed 3D ray launching algorithm, estimation of the microwave oven’s power leakage is obtained for the complete volume of an indoor scenario. The magnitude and the variable nature of the interference is analyzed and the impact in the radio link quality in operating wireless sensors is estimated and compared with radio channel measurements as well as packet measurements. The measurement results reveal the importance of selecting an adequate 802.15.4 channel, as well as the Wireless Sensor Network deployment strategy within this type of environment, in order to optimize energy consumption and increase the overall network performance. The proposed method enables one to estimate potential interference effects in devices operating within the 2.4 GHz band in the complete scenario, prior to wireless sensor network deployment, which can aid in achieving the most optimal network topology.

  1. Recent operating experience with Varian 70 GHz and 140 GHz gyrotrons

    International Nuclear Information System (INIS)

    Felch, K.; Bier, R.; Fox, L.; Huey, H.; Ives, L.; Jory, H.; Lopez, N.; Shively, J.; Spang, S.

    1985-01-01

    The design features and initial test results of Varian 70 GHz and 140 GHz CW gyrotrons are presented. The first experimental 140 GHz tube has achieved an output power of 102 kW at 24% efficiency under pulsed conditions in the desired TE 031 0 cavity mode. Further tests aimed at achieving the design goal of 100 kW CW are currently underway. The 70 GHz tube has achieved an output power of 200 kW under pulsed conditions and possesses a wide dynamic range for output power variations. 6 refs., 8 figs

  2. Band structure analysis in SiGe nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Amato, Michele [' Centro S3' , CNR-Istituto Nanoscienze, via Campi 213/A, 41100 Modena (Italy); Dipartimento di Scienze e Metodi dell' Ingegneria, Universita di Modena e Reggio Emilia, via Amendola 2 Pad. Morselli, I-42100 Reggio Emilia (Italy); Palummo, Maurizia [European Theoretical Spectroscopy Facility (ETSF) (Italy); CNR-INFM-SMC, Dipartimento di Fisica, Universita di Roma, ' Tor Vergata' , via della Ricerca Scientifica 1, 00133 Roma (Italy); Ossicini, Stefano, E-mail: stefano.ossicini@unimore.it [' Centro S3' , CNR-Istituto Nanoscienze, via Campi 213/A, 41100 Modena (Italy) and Dipartimento di Scienze e Metodi dell' Ingegneria, Universita di Modena e Reggio Emilia, via Amendola 2 Pad. Morselli, I-42100 Reggio Emilia (Italy) and European Theoretical Spectroscopy Facility - ETSF (Italy) and Centro Interdipartimentale ' En and Tech' , Universita di Modena e Reggio Emilia, via Amendola 2 Pad. Morselli, I-42100 Reggio Emilia (Italy)

    2012-06-05

    One of the main challenges for Silicon-Germanium nanowires (SiGe NWs) electronics is the possibility to modulate and engine their electronic properties in an easy way, in order to obtain a material with the desired electronic features. Diameter and composition constitute two crucial ways for the modification of the band gap and of the band structure of SiGe NWs. Within the framework of density functional theory we present results of ab initio calculations regarding the band structure dependence of SiGe NWs on diameter and composition. We point out the main differences with respect to the case of pure Si and Ge wires and we discuss the particular features of SiGe NWs that are useful for future technological applications.

  3. Band structure analysis in SiGe nanowires

    International Nuclear Information System (INIS)

    Amato, Michele; Palummo, Maurizia; Ossicini, Stefano

    2012-01-01

    One of the main challenges for Silicon-Germanium nanowires (SiGe NWs) electronics is the possibility to modulate and engine their electronic properties in an easy way, in order to obtain a material with the desired electronic features. Diameter and composition constitute two crucial ways for the modification of the band gap and of the band structure of SiGe NWs. Within the framework of density functional theory we present results of ab initio calculations regarding the band structure dependence of SiGe NWs on diameter and composition. We point out the main differences with respect to the case of pure Si and Ge wires and we discuss the particular features of SiGe NWs that are useful for future technological applications.

  4. Texture-enhanced Al-Cu electrodes on ultrathin Ti buffer layers for high-power durable 2.6 GHz SAW filters

    Science.gov (United States)

    Fu, Sulei; Wang, Weibiao; Xiao, Li; Lu, Zengtian; Li, Qi; Song, Cheng; Zeng, Fei; Pan, Feng

    2018-04-01

    Achieving high resistance to acoustomigration and electromigration in the electrodes used in high-power and high-frequency surface acoustic wave (SAW) filters is important to mobile communications development. In this study, the effects of the Ti buffer layers on the textures and acoustomigration and electromigration resistances of the Al-Cu electrodes were studied comprehensively. The results demonstrate that both power durability and electromigration lifetime are positively correlated with the Al-Cu electrode texture quality. Ultrathin (˜2 nm) Ti can lead to the strongest Al-Cu (111) textured electrodes, with a full width at half maximum of the rocking curve of 2.09°. This represents a remarkable enhancement of the power durability of high-frequency 2.6 GHz SAW filters from 29 dBm to 35 dBm. It also produces lifetime almost 7 times longer than those of electrodes without Ti buffer layers in electromigration tests. X-ray diffraction and transmission electron microscopy analyses revealed that these improved acoustomigration and electromigration resistances can be attributed primarily to the reductions in overall and large-angle grain boundaries in the highly Al-Cu (111) textured electrodes. Furthermore, the growth mechanism of highly Al-Cu texture films is discussed in terms of surface-interface energy balance.

  5. Improving RF Transmit Power and Received Signal Strength in 2.4 GHz ZigBee Based Active RFID System with Embedded Method

    Science.gov (United States)

    Po'ad, F. A.; Ismail, W.; Jusoh, J. F.

    2017-08-01

    This paper describes the experiments and analysis conducted on 2.4 GHz embedded active Radio Frequency Identification (RFID) - Wireless Sensor Network (WSN) based system that has been developed for the purposes of location tracking and monitoring in indoor and outdoor environments. Several experiments are conducted to test the effectiveness and performance of the developed system and two of them is by measuring the Radio Frequency (RF) transmitting power and Received Signal Strength (RSS) to prove that the embedded active RFID tag is capable to generate higher transmit power during data transmission and able to provide better RSS reading compared to standalone RFID tag. Experiments are carried out on two RFID tags which are active RFID tag embedded with GPS and GSM (ER2G); and standalone RFID tag communicating with the same active RFID reader. The developed ER2G contributes 12.26 % transmit power and 6.47 % RSS reading higher than standalone RFID tag. The results conclude that the ER2G gives better performance compared to standalone RFID tag and can be used as guidelines for future design improvements.

  6. Heating power at the substrate, electron temperature, and electron density in 2.45 GHz low-pressure microwave plasma

    Science.gov (United States)

    Kais, A.; Lo, J.; Thérèse, L.; Guillot, Ph.

    2018-01-01

    To control the temperature during a plasma treatment, an understanding of the link between the plasma parameters and the fundamental process responsible for the heating is required. In this work, the power supplied by the plasma onto the surface of a glass substrate is measured using the calorimetric method. It has been shown that the powers deposited by ions and electrons, and their recombination at the surface are the main contributions to the heating power. Each contribution is estimated according to the theory commonly used in the literature. Using the corona balance, the Modified Boltzmann Plot (MBP) is employed to determine the electron temperature. A correlation between the power deposited by the plasma and the results of the MBP has been established. This correlation has been used to estimate the electron number density independent of the Langmuir probe in considered conditions.

  7. Sensitivity of the crystal quality of SiGe layers grown at low temperatures by trisilane and germane

    Energy Technology Data Exchange (ETDEWEB)

    Abedin, A., E-mail: aabedin@kth.se; Moeen, M.; Cappetta, C.; Östling, M.; Radamson, H.H., E-mail: rad@kth.se

    2016-08-31

    This work investigates the crystal quality of SiGe layers grown at low temperatures using trisilane, and germane precursors. The crystal quality sensitivity was monitored for hydrogen chloride and/or minor oxygen amount during SiGe epitaxy or at the interface of SiGe/Si layers. The quality of the epi-layers was examined by quantifying noise parameter, K{sub 1/f} obtained from the power spectral density vs. 1/f curves. The results indicate that while it is difficult to detect small defect densities in SiGe layers by physical material characterization, the noise measurement could reveal the effects of oxygen contamination as low as 0.16 mPa inside and in the interface of the layers. - Highlights: • SiGe layers were grown using trisilane and germane. • Effect of HCl flow on Ge content and growth rate was investigated. • O{sub 2} partial pressures up to 4.3 mPa did not affect x-ray diffraction pattern. • O{sub 2} partial pressures as low as 0.16 mPa increased the noise level. • HCl increased metal contaminations of the layers and the noise level consequently.

  8. Extended x-ray absorption fine structure studies of amorphous and crystalline Si-Ge alloys with synchrotron radiation

    International Nuclear Information System (INIS)

    Kajiyama, Hiroshi

    1988-01-01

    Extended X-ray absorption fine structure (EXAFS) is a powerful probe to study the local structure around the atom of a specific element. In conventional EXAFS analysis, it has been known that reliable structures are obtained with the different values of absorption edge energy for different neighboring atoms. It is shown in this study that the Ge-K edge EXAFS resulting from the Ge-Ge and Ge-Si bonds in hydrogenated amorphous Si-Ge alloys was able to be excellently explained by a unique absorption edge energy value, provided that a newly developed formula based on the spherical wave function of photoelectrons is used. The microscopic structures of hydrogenated amorphous Si-Ge alloys and crystalline Si-Ge alloys have been determined using the EXAFS method. The lengths of Ge-Ge and Ge-Si bonds were constant throughout their entire composition range, and it was found that the length of Ge-Si bond was close to the average value of the bond lengths of both Ge and Si crystals. In crystalline Si-Ge alloys, it has been shown that the bonds relaxed completely, while the lattice constant varied monotonously with the composition. (Kako, I.)

  9. The Atacama Cosmology Telescope: A Measurement of the 600 less than l less than 8000 Cosmic Microwave Background Power Spectrum at 148 GHz

    Science.gov (United States)

    Fowler, J. W.; Acquaviva, V.; Ade, P. A. R.; Aguirre, P.; Amiri, M.; Appel, J. W.; Barrientos, L. F.; Bassistelli, E. S.; Bond, J. R.; Brown, B.; hide

    2010-01-01

    We present a measurement of the angular power spectrum of the cosmic microwave background (CMB) radiation observed at 148 GHz. The measurement uses maps with 1.4' angular resolution made with data from the Atacama Cosmology Telescope (ACT). The observations cover 228 deg(sup 2) of the southern sky, in a 4 deg. 2-wide strip centered on declination 53 deg. South. The CMB at arc minute angular scales is particularly sensitive to the Silk damping scale, to the Sunyaev-Zel'dovich (SZ) effect from galaxy dusters, and to emission by radio sources and dusty galaxies. After masking the 108 brightest point sources in our maps, we estimate the power spectrum between 600 less than l less than 8000 using the adaptive multi-taper method to minimize spectral leakage and maximize use of the full data set. Our absolute calibration is based on observations of Uranus. To verify the calibration and test the fidelity of our map at large angular scales, we cross-correlate the ACT map to the WMAP map and recover the WMAP power spectrum from 250 less than l less than 1150. The power beyond the Silk damping tail of the CMB (l approximately 5000) is consistent with models of the emission from point sources. We quantify the contribution of SZ clusters to the power spectrum by fitting to a model normalized to sigma 8 = 0.8. We constrain the model's amplitude A(sub sz) less than 1.63 (95% CL). If interpreted as a measurement of as, this implies sigma (sup SZ) (sub 8) less than 0.86 (95% CL) given our SZ model. A fit of ACT and WMAP five-year data jointly to a 6-parameter ACDM model plus point sources and the SZ effect is consistent with these results.

  10. 11.9 W output power at 4 GHz from 1 mm AlGaN/GaN HEMT

    NARCIS (Netherlands)

    Krämer, M.C.J.C.M.; Karouta, F.; Kwaspen, J.J.M.; Rudzinski, M.; Larsen, P.K.; Suijker, E.M.; Hek, P.A. de; Rödle, T.; Volokhine, I.; Kaufmann, L.M.F.

    2008-01-01

    A high electrical breakdown field combined with a high electron saturation velocity make GaN very attractive for high power high frequency electronics. The maximum drain current densities of AlGaN/GaN HFETs range from 1.0 A/mm to 1.5 A/mm [1-3]. Hence, it is obvious that breakdown voltages over 160

  11. 5.2-GHz RF Power Harvester in 0.18-/spl mu/m CMOS for Implantable Intraocular Pressure Monitoring

    KAUST Repository

    Ouda, Mahmoud H.

    2013-04-17

    A first fully integrated 5.2-GHz CMOS-based RF power harvester with an on-chip antenna is presented in this paper. The design is optimized for sensors implanted inside the eye to wirelessly monitor the intraocular pressure of glaucoma patients. It includes a five-stage RF rectifier with an on-chip antenna, a dc voltage limiter, two voltage sensors, a low dropout voltage regulator, and MOSCAP based on-chip storage. The chip has been designed and fabricated in a standard 0.18-μm CMOS technology. To emulate the eye environment in measurements, a custom test setup is developed that comprises Plexiglass cavities filled with saline solution. Measurements in this setup show that the proposed chip can be charged to 1 V wirelessly from a 5-W transmitter 3 cm away from the harvester chip. The energy that is stored on the 5-nF on-chip MOSCAP when charged to 1 V is 2.5 nJ, which is sufficient to drive an arbitrary 100-μW load for 9 μs at regulated 0.8 V. Simulated efficiency of the rectifier is 42% at -7 dBm of input power.

  12. Compact and Ultra-Low-Power 2.4 GHz LNA for On-body Communication Devices

    DEFF Research Database (Denmark)

    Ruaro, Andrea; Gülstorff, Steen; Jakobsen, Kaj Bjarne

    2015-01-01

    components. The noise figure is as low as 1.5 dB with an associated power gain of 6.2 dB while it consumes less than 1 mW drawn from a 1 V supply. The input third-order intercept point (IIP3) and the 1-dB compression point (P1dB) are −11 and −9 dBm, respectively. The input and output return loss are better...

  13. Design of ultralow power receiver front-ends for 2.4 GHz wireless sensor network applications

    International Nuclear Information System (INIS)

    Zhang Meng; Li Zhiqun; Wang Zengqi; Wu Chenjian; Chen Liang

    2014-01-01

    This paper presents the design of an ultralow power receiver front-end designed for a wireless sensor network (WSN) in a 0.18 μm CMOS process. The author designs two front-ends working in the saturation region and the subthreshold region respectively. The front-ends contain a two-stage cross-coupling cascaded common-gate (CG) LNA and a quadrature Gilbert IQ mixer. The measured conversion gain is variable with high gain at 24 dB and low gain at 7 dB for the saturation one, and high gain at 22 dB and low gain at 5 dB for the subthreshold one. The noise figure (NF) at high gain mode is 5.1 dB and 6.3 dB for each. The input 1 dB compression point (IP1dB) at low gain mode is about −6 dBm and −3 dBm for each. The front-ends consume about 2.1 mA current from 1.8 V power supply for the saturation one and 1.3 mA current for the subthreshold one. The measured results show that, comparing with the power consumption saving, it is worth making sacrifices on the performance for using the subthreshold technology. (semiconductor integrated circuits)

  14. Low conversion loss 94 GHz and 188 GHz doublers in InP DHBT technology

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Johansen, Tom Keinicke; Squartecchia, Michele

    2017-01-01

    An Indium Phosphide (InP) Double Heterojunction Bipolar Transistor (DHBT) process has been utilized to design two doublers to cover the 94 GHz and 188 GHz bands. The 94 GHz doubler employs 4-finger DHBTs and provides conversion loss of 2 dB. A maximum output power of nearly 3 dBm is measured whil...... operate over a broad bandwidth. The total circuit area of each chip is 1.41 mm2....

  15. DATA transmission by 2.4 GHz radio frequency and LAN from Nuclear Power Plant to office

    International Nuclear Information System (INIS)

    Tsuji, Kenji; Masuda, Ryota; Hukui, Takuya

    2011-01-01

    Additional monitoring is occasionally done on suspicious equipment such as pumps, motors, valves and so on, when monitoring parameters are different from normal operation in Nuclear Power Plant. If the suspicious equipment is located in high radiation area, it is hard to arrange for the additional monitoring. So, wireless data transmission system is desired. And maintenance persons desire to watch the additional monitoring data in their office on P.C. We can enable to transfer the desired live data from sensors in NPP to the maintenance person's office, using by ZigBee system connected to LAN. In order to enlarge the operating term, the battery for sensors is switched on or off by the signal related to sleeping function on ZigBee sensor-terminal. (author)

  16. Class 1 bluetooth power amplifier with 24dBm output power and 48% PAE at 2.4GHz in 0.25um CMOS

    NARCIS (Netherlands)

    Vathulay, V.; Sowlati, T.; Leenaerts, D.M.W.

    2001-01-01

    In this paper, we report an RF power amplifier design in digital CMOS technology for the Class 1 power level specification (20 dBm) in the Bluetooth Communications standard. We have also investigated hot carrier effects under large signal RF operation of the power amplifier. The two stage circuit,

  17. Environmental assessment for the Satellite Power System (SPS): studies of honey bees exposed to 2. 45 GHz continuous-wave electromagnetic energy

    Energy Technology Data Exchange (ETDEWEB)

    Gary, N E; Westerdahl, B B

    1980-12-01

    A system for small animal exposure was developed for treating honey bees, Apis mellifera L., in brood and adult stages, with 2.45 GHz continuous wave microwaves at selected power densities and exposure times. Post-treatment brood development was normal and teratological effects were not detected at exposures of 3 to 50 mw/cm/sup 2/ for 30 minutes. Post-treatment survival, longevity, orientation, navigation, and memory of adult bees were also normal after exposures of 3 to 50 mw/cm/sup 2/ for 30 minutes. Post-treatment longevity of confined bees in the laboratory was normal after exposures of 3 to 50 mw/cm/sup 2/ for 24 hours. Thermoregulation of brood nest, foraging activity, brood rearing, and social interaction were not affected by chronic exposure to 1 mw/cm/sup 2/ during 28 days. In dynamic behavioral bioassays the frequency of entry and duration of activity of unrestrained, foraging adult bees was identical in microwave-exposed (5 to 40 mw/cm/sup 2/) areas versus control areas.

  18. Design of a high-power, high-gain, 2nd harmonic, 22.848 GHz gyroklystron

    Energy Technology Data Exchange (ETDEWEB)

    Veale, M. [University of California, Berkeley, CA, 24720 (United States); Purohit, P. [Qualcomm Technologies, Inc. USA (United States); Lawson, W. [University of Maryland, College Park, MD 20742 (United States)

    2013-08-15

    In this paper we consider the design of a four-cavity, high-gain K-band gyroklystron experiment for high gradient structure testing. The frequency doubling gyroklystron utilizes a beam voltage of 500 kV and a beam current of 200 A from a magnetron injection gun (MIG) originally designed for a lower-frequency device. The microwave circuit features input and gain cavities in the circular TE{sub 011} mode and penultimate and output cavities that operate at the second harmonic in the TE{sub 021} mode. We investigate the MIG performance and study the behavior of the circuit for different values of perpendicular to parallel velocity ratio (α= V{sub ⊥}/ V{sub z}). This microwave tube is expected to be able to produce at least 20 MW of power in 1μs pulses at a repetition rate of at least 120 Hz. A maximum efficiency of 26% and a large signal gain of 58 dB under zero-drive stable conditions were simulated for a velocity ratio equal to 1.35.

  19. 110GHz ECH on DIII-D

    International Nuclear Information System (INIS)

    Cary, W.P.; Allen, J.C.; Callis, R.W.; Doane, J.L.; Harris, T.E.; Moetler, C.P.; Neren, A.; Prater, P.; Rensen, D.

    1992-01-01

    This paper reports on a new high power electron cyclotron heating (ECH) system which has been introduced on DIII-D. This system is designed to operate at 110 GHz with a total output power of 2 MW. The system consists of four Varian VGT-8011 gyrotrons (output power of 500 kW), and their associated support equipment. All components have been designed for up to a 10 second pulse duration. The 110 GHz system is intended to further progress in rf current drive experiments on DIII-D when used in conjunction with the existing 60 GHz ECH (1. 6 MW) , and the 30-60 MHz ICH (2MW) systems. H-mode physics, plasma stabilization experiments and transport studies are also to be conducted at 110 GHz

  20. A 60 GHz Frequency Generator Based on a 20 GHz Oscillator and an Implicit Multiplier

    NARCIS (Netherlands)

    Zong, Z.; Babaie, M.; Staszewski, R.B.

    2016-01-01

    This paper proposes a mm-wave frequency generation technique that improves its phase noise (PN) performance and power efficiency. The main idea is that a fundamental 20 GHz signal and its sufficiently strong third harmonic at 60 GHz are generated simultaneously in a single oscillator. The desired 60

  1. Surface tension and density of Si-Ge melts

    Science.gov (United States)

    Ricci, Enrica; Amore, Stefano; Giuranno, Donatella; Novakovic, Rada; Tuissi, Ausonio; Sobczak, Natalia; Nowak, Rafal; Korpala, Bartłomiej; Bruzda, Grzegorz

    2014-06-01

    In this work, the surface tension and density of Si-Ge liquid alloys were determined by the pendant drop method. Over the range of measurements, both properties show a linear temperature dependence and a nonlinear concentration dependence. Indeed, the density decreases with increasing silicon content exhibiting positive deviation from ideality, while the surface tension increases and deviates negatively with respect to the ideal solution model. Taking into account the Si-Ge phase diagram, a simple lens type, the surface tension behavior of the Si-Ge liquid alloys was analyzed in the framework of the Quasi-Chemical Approximation for the Regular Solutions model. The new experimental results were compared with a few data available in the literature, obtained by the containerless method.

  2. 6‐GHz‐to‐18‐GHz AlGaN/GaN Cascaded Nonuniform Distributed Power Amplifier MMIC Using Load Modulation of Increased Series Gate Capacitance

    Directory of Open Access Journals (Sweden)

    Dong‐Hwan Shin

    2017-10-01

    Full Text Available A 6‐GHz‐to‐18‐GHz monolithic nonuniform distributed power amplifier has been designed using the load modulation of increased series gate capacitance. This amplifier was implemented using a 0.25‐μm AlGaN/GaN HEMT process on a SiC substrate. With the proposed load modulation, we enhanced the amplifier's simulated performance by 4.8 dB in output power, and by 13.1% in power‐added efficiency (PAE at the upper limit of the bandwidth, compared with an amplifier with uniform gate coupling capacitors. Under the pulse‐mode condition of a 100‐μs pulse period and a 10% duty cycle, the fabricated power amplifier showed a saturated output power of 39.5 dBm (9 W to 40.4 dBm (11 W with an associated PAE of 17% to 22%, and input/output return losses of more than 10 dB within 6 GHz to 18 GHz.

  3. Efficient tunable luminescence of SiGe alloy sheet polymers

    International Nuclear Information System (INIS)

    Vogg, G.; Meyer, A. J.-P.; Miesner, C.; Brandt, M. S.; Stutzmann, M.

    2001-01-01

    Crystalline SiGe alloy sheet polymers were topotactically prepared from epitaxially grown calcium germanosilicide Ca(Si 1-x Ge x ) 2 precursor films in the whole composition range. These polygermanosilynes are found to be a well-defined mixture of the known siloxene and polygermyne sheet polymers with the OH groups exclusively bonded to silicon. The optical properties determined by photoluminescence and optical reflection measurements identify the mixed SiGe sheet polymers as direct semiconductors with efficient luminescence tunable in the energy range between 2.4 and 1.3 eV. [copyright] 2001 American Institute of Physics

  4. Heavy Ion Current Transients in SiGe HBTs

    Science.gov (United States)

    Pellish, Jonathan A.; Reed, Robert A.; Vizkelethy, Gyorgy; McMorrow, Dale; Ferlet-Cavrois, Veronique; Baggio, Jacques; Paillet, Philipe; Duhanel, Olivier; Phillips, Stanley D.; Sutton, Akil K.; hide

    2009-01-01

    Time-resolved ion beam induced charge reveals heavy ion response of IBM 5AM SiGe HBT: a) Position correlation[ b) Unique response for different bias schemes; c) Similarities to TPA pulsed-laser data. Heavy ion broad-beam transients provide more realistic device response: a) Feedback using microbeam data; b) Overcome issues of LET and ion range with microbeam. Both micro- and broad-beam data sets yield valuable input for TCAD simulations. Uncover detailed mechanisms for SiGe HBTs and other devices fabricated on lightly-doped substrates.

  5. Interface Engineering for Atomic Layer Deposited Alumina Gate Dielectric on SiGe Substrates.

    OpenAIRE

    Zhang, L; Guo, Y; Hassan, VV; Tang, K; Foad, MA; Woicik, JC; Pianetta, P; Robertson, John; McIntyre, PC

    2016-01-01

    Optimization of the interface between high-k dielectrics and SiGe substrates is a challenging topic due to the complexity arising from the coexistence of Si and Ge interfacial oxides. Defective high-k/SiGe interfaces limit future applications of SiGe as a channel material for electronic devices. In this paper, we identify the surface layer structure of as-received SiGe and Al2O3/SiGe structures based on soft and hard X-ray photoelectron spectroscopy. As-received SiGe substrates have native Si...

  6. Experiments and Modeling of Si-Ge Interdiffusion with Partial Strain Relaxation in Epitaxial SiGe Heterostructures

    KAUST Repository

    Dong, Y.

    2014-07-26

    Si-Ge interdiffusion and strain relaxation were studied in a metastable SiGe epitaxial structure. With Ge concentration profiling and ex-situ strain analysis, it was shown that during thermal anneals, both Si-Ge interdiffusion and strain relaxation occurred. Furthermore, the time evolutions of both strain relaxation and interdiffusion were characterized. It showed that during the ramp-up stage of thermal anneals at higher temperatures (800°C and 840°C), the degree of relaxation, R, reached a “plateau”, while interdiffusion was negligible. With the approximation that the R value is constant after the ramp-up stage, a quantitative interdiffusivity model was built to account for both the effect of strain relaxation and the impact of the relaxation induced dislocations, which gave good agreement with the experiment data.

  7. Silicon-germanium (Sige) nanostructures production, properties and applications in electronics

    CERN Document Server

    Usami, N

    2011-01-01

    Nanostructured silicon-germanium (SiGe) provides the prospect of novel and enhanced electronic device performance. This book reviews the materials science and technology of SiGe nanostructures, including crystal growth, fabrication of nanostructures, material properties and applications in electronics.$bNanostructured silicon-germanium (SiGe) opens up the prospects of novel and enhanced electronic device performance, especially for semiconductor devices. Silicon-germanium (SiGe) nanostructures reviews the materials science of nanostructures and their properties and applications in different electronic devices. The introductory part one covers the structural properties of SiGe nanostructures, with a further chapter discussing electronic band structures of SiGe alloys. Part two concentrates on the formation of SiGe nanostructures, with chapters on different methods of crystal growth such as molecular beam epitaxy and chemical vapour deposition. This part also includes chapters covering strain engineering and mo...

  8. Study of Si-Ge interdiffusion with phosphorus doping

    KAUST Repository

    Cai, Feiyang; Anjum, Dalaver H.; Zhang, Xixiang; Xia, Guangrui

    2016-01-01

    Si-Ge interdiffusion with phosphorus doping was investigated by both experiments and modeling. Ge/Si1-x Ge x/Ge multi-layer structures with 0.75Si-Ge interdiffusivity, which is 2–8 times of that of the undoped sample. The doping dependence of the Si-Ge interdiffusion was modelled by a Fermi-enhancement factor. The results show that the Si-Ge interdiffusion coefficient is proportional to n2/n2i for the conditions studied, which indicates that the interdiffusion in a high Ge fraction range with n-type doping is dominated by V2− defects. The Fermi-enhancement factor was shown to have a relatively weak dependence on the temperature and the Ge fraction. The results are relevant to the structure and thermal processing condition design of n-type doped Ge/Si and Ge/SiGe based devices such as Ge/Si lasers.

  9. Study of Si-Ge interdiffusion with phosphorus doping

    KAUST Repository

    Cai, Feiyang

    2016-10-28

    Si-Ge interdiffusion with phosphorus doping was investigated by both experiments and modeling. Ge/Si1-x Ge x/Ge multi-layer structures with 0.75Si-Ge interdiffusivity, which is 2–8 times of that of the undoped sample. The doping dependence of the Si-Ge interdiffusion was modelled by a Fermi-enhancement factor. The results show that the Si-Ge interdiffusion coefficient is proportional to n2/n2i for the conditions studied, which indicates that the interdiffusion in a high Ge fraction range with n-type doping is dominated by V2− defects. The Fermi-enhancement factor was shown to have a relatively weak dependence on the temperature and the Ge fraction. The results are relevant to the structure and thermal processing condition design of n-type doped Ge/Si and Ge/SiGe based devices such as Ge/Si lasers.

  10. SiGe epitaxial memory for neuromorphic computing with reproducible high performance based on engineered dislocations

    Science.gov (United States)

    Choi, Shinhyun; Tan, Scott H.; Li, Zefan; Kim, Yunjo; Choi, Chanyeol; Chen, Pai-Yu; Yeon, Hanwool; Yu, Shimeng; Kim, Jeehwan

    2018-01-01

    Although several types of architecture combining memory cells and transistors have been used to demonstrate artificial synaptic arrays, they usually present limited scalability and high power consumption. Transistor-free analog switching devices may overcome these limitations, yet the typical switching process they rely on—formation of filaments in an amorphous medium—is not easily controlled and hence hampers the spatial and temporal reproducibility of the performance. Here, we demonstrate analog resistive switching devices that possess desired characteristics for neuromorphic computing networks with minimal performance variations using a single-crystalline SiGe layer epitaxially grown on Si as a switching medium. Such epitaxial random access memories utilize threading dislocations in SiGe to confine metal filaments in a defined, one-dimensional channel. This confinement results in drastically enhanced switching uniformity and long retention/high endurance with a high analog on/off ratio. Simulations using the MNIST handwritten recognition data set prove that epitaxial random access memories can operate with an online learning accuracy of 95.1%.

  11. Reduced thermal conductivity due to scattering centers in p-type SiGe alloys

    International Nuclear Information System (INIS)

    Beaty, J.S.; Rolfe, J.L.; Vandersande, J.; Fleurial. J.P.

    1992-01-01

    This paper reports that a theoretical model has been developed that predicts that the addition of ultra-fine, inert, phonon-scattering centers to SiGe thermoelectric material will reduce its thermal conductivity and improve its figure-of-merit. To investigate this prediction, ultra-fine particulates (20 Angstrom to 200 Angstrom) of boron nitride have been added to boron doped, p-type, 80/20 SiGe. All previous SiGe samples produced from ultra-fine SiGe powder without additions had lower thermal conductivities than standard SiGe, but high temperature (1525 K) heat treatment increased their thermal conductivity back to the value for standard SiGe. Transmission Electron Microscopy has been used to confirm the presence of occluded particulates and X-ray diffraction has been used to determine the composition to be BN

  12. Stable and low contact resistance electrical contacts for high temperature SiGe thermoelectric generators

    KAUST Repository

    Zhang, Bo; Zheng, Tao; Wang, Qingxiao; Guo, Zaibing; Kim, Moon J.; Alshareef, Husam N.; Gnade, Bruce E.

    2018-01-01

    that no interdiffusion takes place between TaAlN and SiGe. A specific contact resistivity of (2.1±1.3)×10−6Ω-cm2 for p-type SiGe and (2.8±1.6)×10−5 Ω-cm2 for n-type SiGe is demonstrated after the high temperature annealing. These results show that TaAlN is a promising

  13. Oxidation kinetics of Si and SiGe by dry rapid thermal oxidation, in-situ steam generation oxidation and dry furnace oxidation

    Science.gov (United States)

    Rozé, Fabien; Gourhant, Olivier; Blanquet, Elisabeth; Bertin, François; Juhel, Marc; Abbate, Francesco; Pribat, Clément; Duru, Romain

    2017-06-01

    The fabrication of ultrathin compressively strained SiGe-On-Insulator layers by the condensation technique is likely a key milestone towards low-power and high performances FD-SOI logic devices. However, the SiGe condensation technique still requires challenges to be solved for an optimized use in an industrial environment. SiGe oxidation kinetics, upon which the condensation technique is founded, has still not reached a consensus in spite of various studies which gave insights into the matter. This paper aims to bridge the gaps between these studies by covering various oxidation processes relevant to today's technological needs with a new and quantitative analysis methodology. We thus address oxidation kinetics of SiGe with three Ge concentrations (0%, 10%, and 30%) by means of dry rapid thermal oxidation, in-situ steam generation oxidation, and dry furnace oxidation. Oxide thicknesses in the 50 Å to 150 Å range grown with oxidation temperatures between 850 and 1100 °C were targeted. The present work shows first that for all investigated processes, oxidation follows a parabolic regime even for thin oxides, which indicates a diffusion-limited oxidation regime. We also observe that, for all investigated processes, the SiGe oxidation rate is systematically higher than that of Si. The amplitude of the variation of oxidation kinetics of SiGe with respect to Si is found to be strongly dependent on the process type. Second, a new quantitative analysis methodology of oxidation kinetics is introduced. This methodology allows us to highlight the dependence of oxidation kinetics on the Ge concentration at the oxidation interface, which is modulated by the pile-up mechanism. Our results show that the oxidation rate increases with the Ge concentration at the oxidation interface.

  14. Design and simulation for the pulse high-voltage DC power supply (HVPS) of 1.2 MW/2.45 GHz HT-7U lower hybrid current drive system

    International Nuclear Information System (INIS)

    Huang Yiyun; Kuang Guangli; Xu Weihua; Liu Baohua; Lin Jianan; Wu Junshuan; Zheng Guanghua; Yang Chunshen

    2000-01-01

    The superconducting tokamak HT-7U has been designed by the Institute of Plasma Physics since 1998 and will be set up before 2003. The 1.2 MW/2.45 GHz HT-7U LHCD (Lower hybrid current drive) system which being the most efficient non-induction device can heat the plasma and drive the plasma current has been efficiently in operation now, and a particular design of the 2.8 MW/-35 kV high-voltage DC power supply has been already completed and will apply to the klystron of LHCD on HT-7 and the future HT-7U, and the project of the power supply has been examined and approved professionally by an authorized group of high-level specialist in the Institute of Plasma Physics. The detailed design of the power supply and the simulation results are referred

  15. 77 FR 45558 - 4.9 GHz Band

    Science.gov (United States)

    2012-08-01

    ..., our rules currently require 4.9 GHz licensees to ``cooperate in the selection and use of channels in... directional and thus can be represented as narrow paths on a coordination map; in contrast, they note, the low-power, less- directional, geographically-dispersed links in a 4.9 GHz network must be represented as a...

  16. Conversion Matrix Analysis of SiGe HBT Gilbert Cell Mixers

    DEFF Research Database (Denmark)

    Johansen, Tom Keinicke; Vidkjær, Jens; Krozer, Viktor

    2004-01-01

    The frequency response of SiGe HBT active mixers based on the Gilbert cell topology is analyzed theoretically. The time-varying operation of the Gilbert cell mixer is taken into account by applying conversion matrix analysis. The main bandwidth limiting mechanisms experienced in SiGe HBT Gilbert ...

  17. Deep Space Cryogenic Power Electronics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Technology Application, Inc. (TAI) is proposing to demonstrate feasibility of implementing silicon germanium (SiGe) strained-gate technology in the power...

  18. KEY COMPARISON: Final report on CCEM key comparison CCEM.RF-K10.CL (GT-RF/99-2) 'Power in 50 Ω coaxial lines, frequency: 50 MHz to 26 GHz' measurement techniques and results

    Science.gov (United States)

    Janik, Dieter; Inoue, T.; Michaud, A.

    2006-01-01

    This report summarizes the results and the measuring methods of an international key comparison between twelve national metrology institutes (NMIs) and is concerning the calibration factor of RF power sensors in the coaxial 3.5 mm line for frequencies up to 26 GHz. Two RF power travelling standards fitted with male PC 3.5 mm connectors were measured at seven frequencies. The following NMIs participated: NMIJ (Japan), NRC (Canada), NIST (USA), METAS (Switzerland), CSIR-NML (South Africa), NMIA (Australia), NPL (UK), SiQ (Slovenia), IEN (Italy), VNIIFTRI (Russian Federation), SPRING (Singapore) and PTB (Germany), as the pilot laboratory. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  19. 79 GHz UWB automotive short range radar – Spectrum allocation and technology trends

    Directory of Open Access Journals (Sweden)

    H.-L. Bloecher

    2009-05-01

    Full Text Available Automotive UWB (Ultra-Wideband short range radar (SSR is on the market as a key technology for novel comfort and safety systems. SiGe based 79 GHz UWB SRR will be a definite candidate for the long term substitution of the 24 GHz UWB SRR. This paper will give an overview of the finished BMBF joint project KOKON and the recently started successing project RoCC, which concentrate on the development of this technology and sensor demonstrators. In both projects, the responsibilities of Daimler AG deal with application based sensor specification, test and evaluation of realized sensor demonstrators. Recent UWB SRR frequency regulation approaches and activitites will be introduced. Furthermore, some first results of Daimler activities within RoCC will be presented, dealing with the packaging and operation of these sensors within the complex car environment.

  20. Stable and low contact resistance electrical contacts for high temperature SiGe thermoelectric generators

    KAUST Repository

    Zhang, Bo

    2018-04-14

    The thermal stability and contact resistance of TaAlN thin films as electrical contacts to SiGe thermoelectric elements are reported. We demonstrate that a sharp interface is maintained after the device annealed at 800°C for over 100h, indicating that no interdiffusion takes place between TaAlN and SiGe. A specific contact resistivity of (2.1±1.3)×10−6Ω-cm2 for p-type SiGe and (2.8±1.6)×10−5 Ω-cm2 for n-type SiGe is demonstrated after the high temperature annealing. These results show that TaAlN is a promising contact material for high temperature thermoelectrics such as SiGe.

  1. Noise Parameter Analysis of SiGe HBTs for Different Sizes in the Breakdown Region

    Directory of Open Access Journals (Sweden)

    Chie-In Lee

    2016-01-01

    Full Text Available Noise parameters of silicon germanium (SiGe heterojunction bipolar transistors (HBTs for different sizes are investigated in the breakdown region for the first time. When the emitter length of SiGe HBTs shortens, minimum noise figure at breakdown decreases. In addition, narrower emitter width also decreases noise figure of SiGe HBTs in the avalanche region. Reduction of noise performance for smaller emitter length and width of SiGe HBTs at breakdown resulted from the lower noise spectral density resulting from the breakdown mechanism. Good agreement between experimental and simulated noise performance at breakdown is achieved for different sized SiGe HBTs. The presented analysis can benefit the RF circuits operating in the breakdown region.

  2. Phosphorus atomic layer doping in SiGe using reduced pressure chemical vapor deposition

    International Nuclear Information System (INIS)

    Yamamoto, Yuji; Heinemann, Bernd; Murota, Junichi; Tillack, Bernd

    2014-01-01

    Phosphorus (P) atomic layer doping in SiGe is investigated at temperatures between 100 °C to 600 °C using a single wafer reduced pressure chemical vapor deposition system. SiGe(100) surface is exposed to PH 3 at different PH 3 partial pressures by interrupting SiGe growth. The impact of the SiGe buffer/cap growth condition (total pressure/SiGe deposition precursors) on P adsorption, incorporation, and segregation are investigated. In the case of SiH 4 -GeH 4 -H 2 gas system, steeper P spikes due to lower segregation are observed by SiGe cap deposition at atmospheric (ATM) pressure compared with reduced pressure (RP). The steepness of P spike of ∼ 5.7 nm/dec is obtained for ATM pressure without reducing deposition temperature. This result may be due to the shift of equilibrium of P adsorption/desorption to desorption direction by higher H 2 pressure. Using Si 2 H 6 -GeH 4 -H 2 gas system for SiGe cap deposition in RP, lowering the SiGe growth temperature is possible, resulting in higher P incorporation and steeper P profile due to reduced desorption and segregation. In the case of Si 2 H 6 -GeH 4 -H 2 gas system, the P dose could be simulated assuming a Langmuir-type kinetics model. Incorporated P shows high electrical activity, indicating P is adsorbed mostly in lattice position. - Highlights: • Phosphorus (P) atomic layer doping in SiGe (100) is investigated using CVD. • P adsorption is suppressed by the hydrogen termination of Ge surface. • By SiGe cap deposition at atmospheric pressure, P segregation was suppressed. • By using Si 2 H 6 -based SiGe cap, P segregation was also suppressed. • The P adsorption process is self-limited and follows Langmuir-type kinetics model

  3. Investigating ESD sensitivity in electrostatic SiGe MEMS

    International Nuclear Information System (INIS)

    Sangameswaran, Sandeep; De Coster, Jeroen; Linten, Dimitri; Scholz, Mirko; Thijs, Steven; Groeseneken, Guido; De Wolf, Ingrid

    2010-01-01

    The sensitivity of electrostatically actuated SiGe microelectromechanical systems to electrostatic discharge events has been investigated in this paper. Torsional micromirrors and RF microelectromechanical systems (MEMS) actuators have been used as two case studies to perform this study. On-wafer electrostatic discharge (ESD) measurement methods, such as the human body model (HBM) and machine model (MM), are discussed. The impact of HBM ESD zap tests on the functionality and behavior of MEMS is explained and the ESD failure levels of MEMS have been verified by failure analysis. It is demonstrated that electrostatic MEMS devices have a high sensitivity to ESD and that it is essential to protect them.

  4. Si, Ge and SiGe wires for sensor application

    International Nuclear Information System (INIS)

    Druzhinin, A.A.; Khoverko, Yu.M.; Ostrovskii, I.P.; Nichkalo, S.I.; Nikolaeva, A.A.; Konopko, L.A.; Stich, I.

    2011-01-01

    Resistance and magnetoresistance of Si, Ge and Si-Ge micro- and nanowires were studied in temperature range 4,2-300 K at magnetic fields up to 14 T. The wires diameters range from 200 nm to 20 μm. Ga-In gates were created to wires and ohmic I-U characteristics were observed in all temperature range. It was found high elastic strain for Ge nanowires (of about 0,7%) as well as high magnitude of magnetoresistance (of about 250% at 14 T), which was used to design multifunctional sensor of simultaneous measurements of strain and magnetic field intensity. (authors)

  5. Superconducting ECR ion source: From 24-28 GHz SECRAL to 45 GHz fourth generation ECR

    Science.gov (United States)

    Zhao, H. W.; Sun, L. T.; Guo, J. W.; Zhang, W. H.; Lu, W.; Wu, W.; Wu, B. M.; Sabbi, G.; Juchno, M.; Hafalia, A.; Ravaioli, E.; Xie, D. Z.

    2018-05-01

    The development of superconducting ECR source with higher magnetic fields and higher microwave frequency is the most straight forward path to achieve higher beam intensity and higher charge state performance. SECRAL, a superconducting third generation ECR ion source, is designed for 24-28 GHz microwave frequency operation with an innovative magnet configuration of sextupole coils located outside the three solenoids. SECRAL at 24 GHz has already produced a number of record beam intensities, such as 40Ar12+ 1.4 emA, 129Xe26+ 1.1 emA, 129Xe30+ 0.36 emA, and 209Bi31+ 0.68 emA. SECRAL-II, an upgraded version of SECRAL, was built successfully in less than 3 years and has recently been commissioned at full power of a 28 GHz gyrotron and three-frequency heating (28 + 45 + 18 GHz). New record beam intensities for highly charged ion production have been achieved, such as 620 eμA 40Ar16+, 15 eμA 40Ar18+, 146 eμA 86Kr28+, 0.5 eμA 86Kr33+, 53 eμA 129Xe38+, and 17 eμA 129Xe42+. Recent beam test results at SECRAL and SECRAL II have demonstrated that the production of more intense highly charged heavy ion beams needs higher microwave power and higher frequency, as the scaling law predicted. A 45 GHz superconducting ECR ion source FECR (a first fourth generation ECR ion source) is being built at IMP. FECR will be the world's first Nb3Sn superconducting-magnet-based ECR ion source with 6.5 T axial mirror field, 3.5 T sextupole field on the plasma chamber inner wall, and 20 kW at a 45 GHz microwave coupling system. This paper will focus on SECRAL performance studies at 24-28 GHz and technical design of 45 GHz FECR, which demonstrates a technical path for highly charged ion beam production from 24 to 28 GHz SECRAL to 45 GHz FECR.

  6. A 90 GHz photoinjector

    International Nuclear Information System (INIS)

    Palmer, D.T.; Hogan, M.J.; Ferrario, M.; Serafini, L.

    1999-01-01

    Photocathode rf guns depend on mode locked laser systems to produce an electron beam at a given phase of the rf. In general, the laser pulse is less than σ 2 = 10'' of rf phase in length and the required stability is on the order of Δφ = 1 At 90 GHz (W-band), these requirements correspond to σ 2 = 333 fsec and Δφ = 33 fsec. Laser system with pulse lengths in the fsec regime are commercially available, the timing stability is a major concern. It is proposed a multi-cell W-band photoinjector that does not require a mode locked laser system. Thereby eliminating the stability requirements at W-band. The laser pulse is allowed to be many rf periods long. In principle, the photoinjector can now be considered as a thermionic rf gun. Instead of using an alpha magnet to compress the electron bunch, which would have a detrimental effect on the transverse hase space quality due to longitudinal phase space mixing, it is here proposed to use long pulse laser system and a pair of undulators to produce a low emittance, high current, ultra-short electron bunch for beam dynamics experiments in the 90 GHz regime

  7. 1.3 GHz superconducting RF cavity program at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Ginsburg, C.M.; Arkan, T.; Barbanotti, S.; Carter, H.; Champion, M.; Cooley, L.; Cooper, C.; Foley, M.; Ge, M.; Grimm, C.; Harms, E.; /Fermilab

    2011-03-01

    At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules (CMs) for Project X, an International Linear Collider (ILC), or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.

  8. Study of low dimensional SiGe island on Si for potential visible Metal-Semiconductor-Metal photodetector

    Science.gov (United States)

    Rahim, Alhan Farhanah Abd; Zainal Badri, Nur'Amirah; Radzali, Rosfariza; Mahmood, Ainorkhilah

    2017-11-01

    In this paper, an investigation of design and simulation of silicon germanium (SiGe) islands on silicon (Si) was presented for potential visible metal semiconductor metal (MSM) photodetector. The characterization of the performances in term of the structural, optical and electrical properties of the structures was analyzed from the simulation results. The project involves simulation using SILVACO Technology Computer Aided Design (TCAD) tools. The different structures of the silicon germanium (SiGe) island on silicon substrate were created, which were large SiGe, small SiGe, combination SiGe and bulk Ge. All the structures were tested for potential Metal Semiconductor Metal (MSM) photodetector. The extracted data such as current versus voltage characteristic, current gain and spectral response were obtained using ATLAS SILVACO tools. The performance of SiGe island structures and bulk Ge on Si substrate as (MSM) photodetector was evaluated by photo and dark current-voltage (I-V) characteristics. It was found that SiGe islands exhibited higher energy band gap compared to bulk Ge. The SiGe islands current-voltage characteristics showed improved current gain compared to bulk Ge. Specifically the enhancement of the islands gain was contributed by the enhanced photo currents and lower dark currents. The spectral responses of the SiGe islands showed peak response at 590 nm (yellow) which is at the visible wavelength. This shows the feasibility of the SiGe islands to be utilized for visible photodetections.

  9. Study of low dimensional SiGe island on Si for potential visible Metal-Semiconductor-Metal photodetector

    Directory of Open Access Journals (Sweden)

    Abd Rahim Alhan Farhanah

    2017-01-01

    Full Text Available In this paper, an investigation of design and simulation of silicon germanium (SiGe islands on silicon (Si was presented for potential visible metal semiconductor metal (MSM photodetector. The characterization of the performances in term of the structural, optical and electrical properties of the structures was analyzed from the simulation results. The project involves simulation using SILVACO Technology Computer Aided Design (TCAD tools. The different structures of the silicon germanium (SiGe island on silicon substrate were created, which were large SiGe, small SiGe, combination SiGe and bulk Ge. All the structures were tested for potential Metal Semiconductor Metal (MSM photodetector. The extracted data such as current versus voltage characteristic, current gain and spectral response were obtained using ATLAS SILVACO tools. The performance of SiGe island structures and bulk Ge on Si substrate as (MSM photodetector was evaluated by photo and dark current-voltage (I-V characteristics. It was found that SiGe islands exhibited higher energy band gap compared to bulk Ge. The SiGe islands current-voltage characteristics showed improved current gain compared to bulk Ge. Specifically the enhancement of the islands gain was contributed by the enhanced photo currents and lower dark currents. The spectral responses of the SiGe islands showed peak response at 590 nm (yellow which is at the visible wavelength. This shows the feasibility of the SiGe islands to be utilized for visible photodetections.

  10. Quantitative SIMS analysis of SiGe composition with low energy O2+ beams

    International Nuclear Information System (INIS)

    Jiang, Z.X.; Kim, K.; Lerma, J.; Corbett, A.; Sieloff, D.; Kottke, M.; Gregory, R.; Schauer, S.

    2006-01-01

    This work explored quantitative analyses of SiGe films on either Si bulk or SOI wafers with low energy SIMS by assuming a constant ratio between the secondary ion yields of Si + and Ge + inside SiGe films. SiGe samples with Ge contents ranging from 15 to 65% have been analyzed with a 1 keV O 2 + beam at normal incidence. For comparison, the samples were also analyzed with RBS and/or AES. The Ge content as measured with SIMS, based on a single SiGe/Si or SiGe/SOI standard, exhibited good agreement with the corresponding RBS and AES data. It was concluded that SIMS was capable of providing accurate characterization of the SiGe composition with the Ge content up to 65%

  11. Heavy Ion Microbeam and Broadbeam Transients in SiGe HBTs

    Science.gov (United States)

    Pellish, Jonathan A.; Reed, Robert A.; McMorrow, Dale; Vizkelethy, Gyorgy; Dodd, Paul E.; Ferlet-Cavrois, Veronique; Baggio, Jacques; Paillet, Philippe; Duhamel, Olivier; Phillips, Stanley D.; hide

    2009-01-01

    SiGe HBT heavy ion current transients are measured using microbeam and both high- and low-energy broadbeam sources. These new data provide detailed insight into the effects of ion range, LET, and strike location.

  12. Traveling-Wave Maser for 32 GHz

    Science.gov (United States)

    Shell, James; Clauss, Robert

    2009-01-01

    The figure depicts a traveling-wave ruby maser that has been designed (though not yet implemented in hardware) to serve as a low-noise amplifier for reception of weak radio signals in the frequency band of 31.8 to 32.3 GHz. The design offers significant improvements over previous designs of 32-GHz traveling-wave masers. In addition, relative to prior designs of 32-GHz amplifiers based on high-electron-mobility transistors, this design affords higher immunity to radio-frequency interference and lower equivalent input noise temperature. In addition to the basic frequency-band and low-noise requirements, the initial design problem included a requirement for capability of operation in a closed-cycle helium refrigerator at a temperature .4 K and a requirement that the design be mechanically simplified, relative to prior designs, in order to minimize the cost of fabrication and assembly. Previous attempts to build 32- GHz traveling-wave masers involved the use of metallic slow-wave structures comprising coupled transverse electromagnetic (TEM)-mode resonators that were subject to very tight tolerances and, hence, were expensive to fabricate and assemble. Impedance matching for coupling signals into and out of these earlier masers was very difficult. A key feature of the design is a slow-wave structure, the metallic portions of which would be mechanically relatively simple in that, unlike in prior slow-wave structures, there would be no internal metal steps, irises, or posts. The metallic portions of the slow-wave structure would consist only of two rectangular metal waveguide arms. The arms would contain sections filled with the active material (ruby) alternating with evanescent-wave sections. This structure would be transparent in both the signal-frequency band (the aforementioned range of 31.8 to 32.3 GHz) and the pump-frequency band (65.75 to 66.75 GHz), and would impose large slowing factors in both frequency bands. Resonant ferrite isolators would be placed in the

  13. A study of 60 GHz intersatellite link applications

    Science.gov (United States)

    Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

    Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

  14. A study of 60 GHz intersatellite link applications

    Science.gov (United States)

    Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

    1983-01-01

    Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

  15. Ultra-low Thermal Conductivity in Si/Ge Hierarchical Superlattice Nanowire.

    Science.gov (United States)

    Mu, Xin; Wang, Lili; Yang, Xueming; Zhang, Pu; To, Albert C; Luo, Tengfei

    2015-11-16

    Due to interfacial phonon scattering and nanoscale size effect, silicon/germanium (Si/Ge) superlattice nanowire (SNW) can have very low thermal conductivity, which is very attractive for thermoelectrics. In this paper, we demonstrate using molecular dynamics simulations that the already low thermal conductivity of Si/Ge SNW can be further reduced by introducing hierarchical structure to form Si/Ge hierarchical superlattice nanowire (H-SNW). The structural hierarchy introduces defects to disrupt the periodicity of regular SNW and scatters coherent phonons, which are the key contributors to thermal transport in regular SNW. Our simulation results show that periodically arranged defects in Si/Ge H-SNW lead to a ~38% reduction of the already low thermal conductivity of regular Si/Ge SNW. By randomizing the arrangement of defects and imposing additional surface complexities to enhance phonon scattering, further reduction in thermal conductivity can be achieved. Compared to pure Si nanowire, the thermal conductivity reduction of Si/Ge H-SNW can be as large as ~95%. It is concluded that the hierarchical structuring is an effective way of reducing thermal conductivity significantly in SNW, which can be a promising path for improving the efficiency of Si/Ge-based SNW thermoelectrics.

  16. 34 GHz, 45 MW pulsed magnicon

    International Nuclear Information System (INIS)

    Nezhevenko, Oleg A.; LaPointe, Michael A.; Yakovlev, Vyacheslav P.; Hirshfield, Jay L.; Serdobintsev, Gennady V.; Kuznetsov, Gennady I.; Persov, Boris Z.; Fix, Alexander

    2002-01-01

    A high efficiency, high power magnicon at 34.272 GHz has been designed and built as a microwave source to develop RF technology for a future multi-TeV electron-positron linear collider. The tube is designed to provide a peak output power of ∼45 MW in a 1 microsecond pulse, with a gain of 55 dB, using a 500 kV, 220 A, 1 mm-diameter electron beam. The status of the tube itself as well as the near-term experimental program is presented

  17. Measurement Results of the Caltech Submillimeter Observatory 230 GHz and 460 GHz Balanced Receivers

    Science.gov (United States)

    Kooi, J. W.; Monje, R. R.; Force, B. L.; Rice, F.; Miller, D.; Phillips, T. G.

    2010-03-01

    The Caltech Submillimeter observatory (CSO) is located on top of Mauna Kea, Hawaii, at an altitude of 4.2km. The existing suite of heterodyne receivers covering the submillimeter band is rapidly aging, and in need of replacement. To this extend we have developed a family of balanced receivers covering the astrophysical important 180-720 GHz atmospheric windows. For the CSO, wide IF bandwidth receivers are implemented in a balanced receiver configuration with dual frequency observation capability. This arrangement was opted to be an optimal compromise between scientific merit and finite funding. In principle, the balanced receiver configuration has the advantage that common mode amplitude noise in the LO system is canceled, while at the same time utilizing all available LO power. Both of these features facilitate the use of commercially available synthesized LO system. In combination with a 4 GHz IF bandwidth, the described receiver layout allows for rapid high resolution spectral line surveys. Dual frequency observation is another important mode of operation offered by the new facility instrumentation. Two band observations are accomplished by separating the H and V polarizations of the incoming signal and routing them via folded optics to the appropriate polarization sensitive balanced mixer. Scientifically this observation mode facilitates pointing for the higher receiver band under mediocre weather conditions and a doubling of scientific throughput (2 x 4 GHz) under good weather conditions. Not only do these changes greatly enhance the spectroscopic capabilities of the CSO, they also enable the observatory to be integrated into the Harvard-Smithsonian Submillimeter Array (eSMA) as an additional baseline. The upgrade of the 345 GHz/650 GHz dual band balanced receivers is not far behind. All the needed hardware has been procured, and commissioning is expected the summer of 2010. The SIS junctions are capable of a 2-12 GHz bandwidth.

  18. Thermal conductivity of nanocrystalline SiGe alloys using molecular dynamics simulations

    Science.gov (United States)

    Abs da Cruz, Carolina; Katcho, Nebil A.; Mingo, Natalio; Veiga, Roberto G. A.

    2013-10-01

    We have studied the effect of nanocrystalline microstructure on the thermal conductivity of SiGe alloys using molecular dynamics simulations. Nanograins are modeled using both the coincidence site lattice and the Voronoi tessellation methods, and the thermal conductivity is computed using the Green-Kubo formalism. We analyze the dependence of the thermal conductivity with temperature, grain size L, and misorientation angle. We find a power dependence of L1/4 of the thermal conductivity with the grain size, instead of the linear dependence shown by non-alloyed nanograined systems. This dependence can be derived analytically underlines the important role that disorder scattering plays even when the grains are of the order of a few nm. This is in contrast to non-alloyed systems, where phonon transport is governed mainly by the boundary scattering. The temperature dependence is weak, in agreement with experimental measurements. The effect of angle misorientation is also small, which stresses the main role played by the disorder scattering.

  19. Si/Ge intermixing during Ge Stranski–Krastanov growth

    Directory of Open Access Journals (Sweden)

    Alain Portavoce

    2014-12-01

    Full Text Available The Stranski–Krastanov growth of Ge islands on Si(001 has been widely studied. The morphology changes of Ge islands during growth, from nucleation to hut/island formation and growth, followed by hut-to-dome island transformation and dislocation nucleation of domes, have been well described, even at the atomic scale, using techniques such as scanning tunneling microscopy and transmission electron microscopy. Although it is known that these islands do not consist of pure Ge (due to Si/Ge intermixing, the composition of the Ge islands is not precisely known. In the present work, atom probe tomography was used to study the composition of buried dome islands at the atomic scale, in the three-dimensional space. The core of the island was shown to contain about 55 atom % Ge, while the Ge composition surrounding this core decreases rapidly in all directions in the islands to reach a Ge concentration of about 15 atom %. The Ge distribution in the islands follows a cylindrical symmetry and Ge segregation is observed only in the {113} facets of the islands. The Ge composition of the wetting layer is not homogeneous, varying from 5 to 30 atom %.

  20. Enhanced Emission of Quantum System in Si-Ge Nanolayer Structure.

    Science.gov (United States)

    Huang, Zhong-Mei; Huang, Wei-Qi; Dong, Tai-Ge; Wang, Gang; Wu, Xue-Ke

    2016-12-01

    It is very interesting that the enhanced peaks near 1150 and 1550 nm are observed in the photoluminescence (PL) spectra in the quantum system of Si-Ge nanolayer structure, which have the emission characteristics of a three-level system with quantum dots (QDs) pumping and emission of quasi-direct-gap band, in our experiment. In the preparing process of Si-Ge nanolayer structure by using a pulsed laser deposition method, it is discovered that the nanocrystals of Si and Ge grow in the (100) and (111) directions after annealing or electron beam irradiation. The enhanced PL peaks with multi-longitudinal-mode are measured at room temperature in the super-lattice of Si-Ge nanolayer quantum system on SOI.

  1. Metastability and relaxation in tensile SiGe on Ge(001) virtual substrates

    International Nuclear Information System (INIS)

    Frigerio, Jacopo; Lodari, Mario; Chrastina, Daniel; Mondiali, Valeria; Isella, Giovanni; Bollani, Monica

    2014-01-01

    We systematically study the heteroepitaxy of SiGe alloys on Ge virtual substrates in order to understand strain relaxation processes and maximize the tensile strain in the SiGe layer. The degree of relaxation is measured by high-resolution x-ray diffraction, and surface morphology is characterized by atomic force microscopy. The results are analyzed in terms of a numerical model, which considers dislocation nucleation, multiplication, thermally activated glide, and strain-dependent blocking. Relaxation is found to be sensitive to growth rate and substrate temperature as well as epilayer misfit and thickness, and growth parameters are found which allow a SiGe film with over 4 GPa of tensile stress to be obtained.

  2. Heteroepitaxial Growth of Vacuum-Evaporated Si-Ge Films on Nano structured Silicon Substrates

    International Nuclear Information System (INIS)

    Ayu Wazira Azhari; Ayu Wazira Azhari; Kamaruzzaman Sopian; Saleem Hussain Zaidi

    2015-01-01

    In this study, a low-cost vacuum-evaporated technique is used in the heteroepitaxial growth of Si-Ge films. Three different surface variations are employed: for example polished Si, Si micro pyramids and Si nano pillars profiles. A simple metal-assisted chemical etching method is used to fabricate the Si nano pillars, with Ag acting as a catalyst. Following deposition, substrates are subjected to post-deposition thermal annealing at 1000 degree Celsius to improve the crystallinity of the Ge layer. Optical and morphological studies of surface area are conducted using field emission scanning electron microscopy (FE-SEM), Energy Dispersive X-ray (EDX), Raman spectroscopy and infrared spectroscopy. From the infrared spectroscopy analysis, the energy bandgap for Si-Ge films is estimated to be around 0.94 eV. This high-quality Si-Ge film is most favourable for optics, optoelectronics and high-efficiency solar cell applications. (author)

  3. Interface bond relaxation on the thermal conductivity of Si/Ge core-shell nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Weifeng; He, Yan; Ouyang, Gang, E-mail: gangouy@hunnu.edu.cn [Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Synergetic Innovation Center for Quantum Effects and Applications(SICQEA), Hunan Normal University, Changsha 410081 (China); Sun, Changqing [School of Electrical & Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2016-01-15

    The thermal conductivity of Si/Ge core-shell nanowires (CSNWs) is investigated on the basis of atomic-bond-relaxation consideration and continuum mechanics. An analytical model is developed to clarify the interface bond relaxation of Si/Ge CSNWs. It is found that the thermal conductivity of Si core can be modulated through covering with Ge epitaxial layers. The change of thermal conductivity in Si/Ge CSNWs should be attributed to the surface relaxation and interface mismatch between inner Si nanowire and outer Ge epitaxial layer. Our results are in well agreement with the experimental measurements and simulations, suggesting that the presented method provides a fundamental insight of the thermal conductivity of CSNWs from the atomistic origin.

  4. A Wide-Band High-Gain Compact SIS Receiver Utilizing a 300-μW SiGe IF LNA

    Science.gov (United States)

    Montazeri, Shirin; Grimes, Paul K.; Tong, Cheuk-Yu Edward; Bardin, Joseph C.

    2017-06-01

    Low-power low-noise amplifiers integrated with superconductor-insulator-superconductor (SIS) mixers are required to enable implementation of large-scale focal plane arrays. In this work, a 220-GHz SIS mixer has been integrated with a high-gain broad-band low-power IF amplifier into a compact receiver module. The low noise amplifier (LNA) was specifically designed to match to the SIS output impedance and contributes less than 7 K to the system noise temperature over the 4-8 GHz IF frequency range. A receiver noise temperature of 30-45 K was measured for a local oscillator frequency of 220 GHz over an IF spanning 4-8 GHz. The LNA power dissipation was only 300-μW. To the best of the authors' knowledge, this is the lowest power consumption reported for a high-gain wide-band LNA directly integrated with an SIS mixer.

  5. Experimental measurements on a 100 GHz frequency tunable quasioptical gyrotron

    International Nuclear Information System (INIS)

    Alberti, S.; Tran, M.Q.; Hogge, J.P.; Tran, T.M.; Bondeson, A.; Muggli, P.; Perrenoud, A.; Joedicke, B.; Mathews, H.G.

    1990-01-01

    Experiments on a 100 GHz quasioptical (QO) gyrotron operating at the fundamental (ω=Ω ce ) are described. Powers larger than 90 kW at an efficiency of about 12% were achieved. Depending on the electron beam parameters, the frequency spectrum of the output can be either single moded or multimoded. One of the main advantages of the QO gyrotron over the conventional gyrotron is its continuous frequency tunability. Various techniques to tune the output frequency have been tested, such as changing the mirror separation, the beam voltage, or the main magnetic field. Within the limitations of the present setup, 5% tunability was achieved. The QO gyrotron designed for operation at the fundamental frequency exhibits simultaneous emission at 100 GHz (fundamental) and 200 GHz (second harmonic). For a beam current of 4 A, 20% of the total rf power is emitted at the second harmonic

  6. Transformation of point defects under annealing of neutron-irradiated Si and Si:Ge

    International Nuclear Information System (INIS)

    Pomozov, Yu.V.; Khirunenko, L.I.; Shakhovtsev, V.I.; Yashnik, V.I.

    1990-01-01

    Transformation of point radiation defects under isochronous annealing of neurton-irradaited Si and Si:Ge is studied. It is determined, that occurence of several new centers which produce A-centre range absorption bands is observed at annealing within 423-493 K temperature range. It is shown that vacancy and oxygen are included in the centers composition. It is found that VO centre transformation into VO 2 at annealing occurs via intermediate stage in contrast to that occuring in electron-irradiated crystals via VO direct diffusion to interstitial oxygen. Transformation of centers under Si ansd Si:Ge annealing occurs similarly

  7. Electrical characterisation of SiGe heterojunction bipolar transistors and Si pseudo-HBTS

    Science.gov (United States)

    De Barros, O.; Le Tron, B.; Woods, R. C.; Giroult-Matlakowski, G.; Vincent, G.; Brémond, G.

    1996-08-01

    This paper reports an electrical characterisation of the emitter-base junction of Si pseudo-HBTs and SiGe HBTs fabricated in a CMOS compatible single polysilicon self-aligned process. From the reverse characteristics it appears that the definition of the emitter-base junction by plasma etching induces peripheral defects that increase the base current of the transistors. Deep level transient spectroscopy measurements show a deep level in the case of SiGe base, whose spatial origin is not fully determinate up to now.

  8. Arbitrary waveform modulated pulse EPR at 200 GHz

    Science.gov (United States)

    Kaminker, Ilia; Barnes, Ryan; Han, Songi

    2017-06-01

    We report here on the implementation of arbitrary waveform generation (AWG) capabilities at ∼200 GHz into an Electron Paramagnetic Resonance (EPR) and Dynamic Nuclear Polarization (DNP) instrument platform operating at 7 T. This is achieved with the integration of a 1 GHz, 2 channel, digital to analog converter (DAC) board that enables the generation of coherent arbitrary waveforms at Ku-band frequencies with 1 ns resolution into an existing architecture of a solid state amplifier multiplier chain (AMC). This allows for the generation of arbitrary phase- and amplitude-modulated waveforms at 200 GHz with >150 mW power. We find that the non-linearity of the AMC poses significant difficulties in generating amplitude-modulated pulses at 200 GHz. We demonstrate that in the power-limited regime of ω1 10 MHz) spin manipulation in incoherent (inversion), as well as coherent (echo formation) experiments. Highlights include the improvement by one order of magnitude in inversion bandwidth compared to that of conventional rectangular pulses, as well as a factor of two in improvement in the refocused echo intensity at 200 GHz.

  9. Effect of high-temperature annealing on the microstructure and thermoelectric properties of GaP doped SiGe. M.S. Thesis

    Science.gov (United States)

    Draper, Susan L.

    1987-01-01

    Annealing of GaP doped SiGe will significantly alter the thermoelectric properties of the material resulting in increased performance as measured by the figure of merit Z and the power factor P. The microstructures and corresponding thermoelectric properties after annealing in the 1100 to 1300 C temperature range have been examined to correlate performance improvement with annealing history. The figure of merit and power factor were both improved by homogenizing the material and limiting the amount of cross-doping. Annealing at 1215 C for 100 hr resulted in the best combination of thermoelectric properties with a resultant figure of merit exceeding 1x10 to the -3 deg C to the -1 and a power factor of 44 microW/cm/deg C sq for the temperature range of interest for space power: 400 to 1000 C.

  10. A 2.4GHz ULP OOK single-chip transceiver for healthcare applications

    NARCIS (Netherlands)

    Vidojkovic, M.; Huang, X.; Harpe, P.J.A.; Rampu, S.; Zhou, C.; Huang, Li; Molengraft, van de J.; Imamura, K.; Büsze, B.; Bouwens, F.; Konijnenburg, M.; Santana, J.; Breeschoten, A.; Huisken, J.; Philips, K.; Dolmans, G.; Groot, de H.W.H.

    2011-01-01

    This paper describes an ultra-low power (ULP) single chip transceiver for wireless body area network (WBAN) applications. It supports on-off keying (OOK) modulation, and it operates in the 2.36–2.4 GHz medical BAN and 2.4–2.485 GHz ISM bands. It is implemented in 90 nm CMOS technology. The direct

  11. 2.4GHz energy harvesting for wireless sensor network

    NARCIS (Netherlands)

    Gao, H.; Baltus, P.G.M.; Mahmoudi, R.; Roermund, van A.H.M.

    2011-01-01

    This paper presents the analysis of the performance of charge pump, and the design strategy and efficiency optimization of 2.4GHz micro-power charge pump using 65nm CMOS technology. The model of the charge pump takes account of the threshold voltage variation, bulk modulation, and the major

  12. A 62GHz inductor-peaked rectifier with 7% efficiency

    NARCIS (Netherlands)

    Gao, H.; Matters - Kammerer, M.; Milosevic, D.; Roermund, van A.H.M.; Baltus, P.G.M.

    2013-01-01

    This paper presents the first 62 GHz fully onchip RF-DC rectifier in 65nm CMOS technology. The rectifier is the bottleneck in realizing on-chip wireless power receivers. In this paper, efficiency problems of the mm-wave rectifier are discussed and the inductor-peaked rectifier structure is proposed

  13. Total dose hardness of a commercial SiGe BiCMOS technology

    International Nuclear Information System (INIS)

    Van Vonno, N.; Lucas, R.; Thornberry, D.

    1999-01-01

    Over the past decade SiGe HBT technology has progress from the laboratory to actual commercial applications. When integrated into a BiMOS process, this technology has applications in low-cost space systems. In this paper, we report results of total dose testing of a SiGe/CMOS process accessible through a commercial foundry. (authors)

  14. An X-band Schottky diode mixer in SiGe technology with tunable Marchand balun

    DEFF Research Database (Denmark)

    Michaelsen, Rasmus Schandorph; Johansen, Tom Keinicke; Tamborg, Kjeld M.

    2017-01-01

    In this paper, we propose a double balanced mixer with a tunable Marchand balun. The circuit is designed in a SiGe BiCMOS process using Schottky diodes. The tunability of the Marchand balun is used to enhance critical parameters for double balanced mixers. The local oscillator-IF isolation can...

  15. De-embedding and Modelling of pnp SiGe HBTs

    DEFF Research Database (Denmark)

    Hadziabdic, Dzenan; Jiang, Chenhui; Johansen, Tom Keinicke

    2007-01-01

    In this work we present a direct parameter extraction procedure for SiGe pnp heterojunction bipolar transistor (HBT) large-signal and small-signal models. Test structure parasitics are removed from the measured small-signal parameters using an open-short de-embedding technique, improved to accoun...

  16. A Passive X-Band Double Balanced Mixer Utilizing Diode Connected SiGe HBTs

    DEFF Research Database (Denmark)

    Michaelsen, Rasmus Schandorph; Johansen, Tom Keinicke; Tamborg, Kjeld

    2013-01-01

    In this paper, a passive double balanced mixer in SiGe HBT technology is presented. Due to lack of suitable passive mixing elements in the technology, the mixing elements are formed by diode connected HBTs. The mixer is optimized for use in doppler radars and is highly linear with 1 dB compressio...

  17. Rectenna Technology Program: Ultra light 2.45 GHz rectenna 20 GHz rectenna

    Science.gov (United States)

    Brown, William C.

    1987-01-01

    The program had two general objectives. The first objective was to develop the two plane rectenna format for space application at 2.45 GHz. The resultant foreplane was a thin-film, etched-circuit format fabricated from a laminate composed of 2 mil Kapton F sandwiched between sheets of 1 oz copper. The thin-film foreplane contains half wave dipoles, filter circuits, rectifying Schottky diode, and dc bussing lead. It weighs 160 grams per square meter. Efficiency and dc power output density were measured at 85% and 1 kw/sq m, respectively. Special testing techniques to measure temperature of circuit and diode without perturbing microwave operation using the fluoroptic thermometer were developed. A second objective was to investigate rectenna technology for use at 20 GHz and higher frequencies. Several fabrication formats including the thin-film scaled from 2.45 GHz, ceramic substrate and silk-screening, and monolithic were investigated, with the conclusion that the monolithic approach was the best. A preliminary design of the monolithic rectenna structure and the integrated Schottky diode were made.

  18. 125-GHz Microwave Signal Generation Employing an Integrated Pulse Shaper

    DEFF Research Database (Denmark)

    Liao, Shasha; Ding, Yunhong; Dong, Jianji

    2017-01-01

    We propose and experimentally demonstrate an on-chip pulse shaper for 125-GHz microwave waveform generation. The pulse shaper is implemented based on a silicon-on-insulator (SOI) platform that has a structure with eight-tap finite impulse response (FIR) and there is an amplitude modulator on each...... of the generated microwave waveforms is larger than 100 GHz, and it has wide bandwidth when changing the time delay of the adjacent taps and compactness, capability for integration with electronics and small power consumption are also its merits.......We propose and experimentally demonstrate an on-chip pulse shaper for 125-GHz microwave waveform generation. The pulse shaper is implemented based on a silicon-on-insulator (SOI) platform that has a structure with eight-tap finite impulse response (FIR) and there is an amplitude modulator on each...

  19. SiGe Integrated Circuit Developments for SQUID/TES Readout

    Science.gov (United States)

    Prêle, D.; Voisin, F.; Beillimaz, C.; Chen, S.; Piat, M.; Goldwurm, A.; Laurent, P.

    2018-03-01

    SiGe integrated circuits dedicated to the readout of superconducting bolometer arrays for astrophysics have been developed since more than 10 years at APC. Whether for Cosmic Microwave Background (CMB) observations with the QUBIC ground-based experiment (Aumont et al. in astro-ph.IM, 2016. arXiv:1609.04372) or for the Hot and Energetic Universe science theme with the X-IFU instrument on-board of the ATHENA space mission (Barret et al. in SPIE 9905, space telescopes & instrumentation 2016: UV to γ Ray, 2016. https://doi.org/10.1117/12.2232432), several kinds of Transition Edge Sensor (TES) (Irwin and Hilton, in ENSS (ed) Cryogenic particle detection, Springer, Berlin, 2005) arrays have been investigated. To readout such superconducting detector arrays, we use time or frequency domain multiplexers (TDM, FDM) (Prêle in JINST 10:C08015, 2016. https://doi.org/10.1088/1748-0221/10/08/C08015) with Superconducting QUantum Interference Devices (SQUID). In addition to the SQUID devices, low-noise biasing and amplification are needed. These last functions can be obtained by using BiCMOS SiGe technology in an Application Specific Integrated Circuit (ASIC). ASIC technology allows integration of highly optimised circuits specifically designed for a unique application. Moreover, we could reach very low-noise and wide band amplification using SiGe bipolar transistor either at room or cryogenic temperatures (Cressler in J Phys IV 04(C6):C6-101, 1994. https://doi.org/10.1051/jp4:1994616). This paper discusses the use of SiGe integrated circuits for SQUID/TES readout and gives an update of the last developments dedicated to the QUBIC telescope and to the X-IFU instrument. Both ASIC called SQmux128 and AwaXe are described showing the interest of such SiGe technology for SQUID multiplexer controls.

  20. Electronic structure of O-doped SiGe calculated by DFT + U method

    Science.gov (United States)

    Zhao, Zong-Yan; Yang, Wen; Yang, Pei-Zhi

    2016-12-01

    To more in depth understand the doping effects of oxygen on SiGe alloys, both the micro-structure and properties of O-doped SiGe (including: bulk, (001) surface, and (110) surface) are calculated by DFT + U method in the present work. The calculated results are as follows. (i) The (110) surface is the main exposing surface of SiGe, in which O impurity prefers to occupy the surface vacancy sites. (ii) For O interstitial doping on SiGe (110) surface, the existences of energy states caused by O doping in the band gap not only enhance the infrared light absorption, but also improve the behaviors of photo-generated carriers. (iii) The finding about decreased surface work function of O-doped SiGe (110) surface can confirm previous experimental observations. (iv) In all cases, O doing mainly induces the electronic structures near the band gap to vary, but is not directly involved in these variations. Therefore, these findings in the present work not only can provide further explanation and analysis for the corresponding underlying mechanism for some of the experimental findings reported in the literature, but also conduce to the development of μc-SiGe-based solar cells in the future. Project supported by the Natural Science Foundation of Yunnan Province, China (Grant No. 2015FB123), the 18th Yunnan Province Young Academic and Technical Leaders Reserve Talent Project, China (Grant No. 2015HB015), and the National Natural Science Foundation of China (Grant No. U1037604).

  1. Bi surfactant mediated growth for fabrication of Si/Ge nanostructures and investigation of Si/Ge intermixing by STM

    Energy Technology Data Exchange (ETDEWEB)

    Paul, N.

    2007-10-26

    In the thesis work presented here, we show that Bi is more promising surfactant material than Sb. We demonstrate that by using Bi as a terminating layer on Ge/Si surface, it is possible to distinguish between Si and Ge in Scanning tunnelling microscope (STM). Any attempt to utilize surfactant mediated growth must be preceded by a thorough study of its effect on the the system being investigated. Thus, the third chapter of this thesis deals with an extensive study of the Bi surfactant mediated growth of Ge on Si(111) surface as a function of Ge coverage. The growth is investigated from the single bilayer Ge coverage till the Ge coverage of about 15 BL when the further Ge deposition leads to two-dimensional growth. In the fourth chapter, the unique property of Bi terminating layer on Ge/Si surface to result in an STM height contrast between Si and Ge is explained with possible explanations given for the reason of this apparent height contrast. The controlled fabrication of Ge/Si nanostructures such as nanowires and nanorings is demonstrated. A study on Ge-Si diffusion in the surface layers by a direct method such as STM was impossible previously because of the similar electronic structure of Ge and Si. Since with the Bi terminating surface layer, one is able to distinguish between Ge and Si, the study of intermixing between them is also possible using STM. This method to distinguish between Si and Ge allows one to study intermixing on the nanoscale and to identify the fundamental diffusion processes giving rise to the intermixing. In Chapter 5 we discuss how this could prove useful especially as one could get a local probe over a very narrow Ge-Si interface. A new model is proposed to estimate change in the Ge concentration in the surface layer with time. The values of the activation energies of Ge/Si exchange and Si/Ge exchange are estimated by fitting the experimental data with the model. The Ge/Si intermixing has been studied on a surface having 1 ML Bi ({radical

  2. Integrated 60GHz RF beamforming in CMOS

    CERN Document Server

    Yu, Yikun; van Roermund, Arthur H M

    2011-01-01

    ""Integrated 60GHz RF Beamforming in CMOS"" describes new concepts and design techniques that can be used for 60GHz phased array systems. First, general trends and challenges in low-cost high data-rate 60GHz wireless system are studied, and the phased array technique is introduced to improve the system performance. Second, the system requirements of phase shifters are analyzed, and different phased array architectures are compared. Third, the design and implementation of 60GHz passive and active phase shifters in a CMOS technology are presented. Fourth, the integration of 60GHz phase shifters

  3. New technologies of information treatment in the ERP of the Almaraz and Trillo nuclear power plants

    International Nuclear Information System (INIS)

    Martin Lopez-Suevos, C.; Gonzalez Crego, E.

    2013-01-01

    The Almaraz and Trillo Nuclear Power Plants are equipped with an Integrated Operation Management System (SIGE), which covers practically all of their transactional and management needs in all areas, with the exception of some specific engineering and simulation tools. In recent years, applications based on new computer technologies have been developed and integrated into the SIGE, including a Maintenance Dashboard, an Admissions Office ant the use of bar code readers, all of which are described in this article. (Author)

  4. SigE Is a Chaperone for the Salmonella enterica Serovar Typhimurium Invasion Protein SigD

    OpenAIRE

    Darwin, K. Heran; Robinson, Lloyd S.; Miller, Virginia L.

    2001-01-01

    SigD is translocated into eucaryotic cells by a type III secretion system. In this work, evidence that the putative chaperone SigE directly interacts with SigD is presented. A bacterial two-hybrid system demonstrated that SigE can interact with itself and SigD. In addition, SigD was specifically copurified with SigE-His6 on a nickel column.

  5. Structural, Dynamic, and Vibrational Properties during Heat Transfer in Si/Ge Superlattices: A Car-Parrinello Molecular Dynamics Study

    OpenAIRE

    Ji, Pengfei; Zhang, Yuwen; Yang, Mo

    2016-01-01

    The structural, dynamic, and vibrational properties during the heat transfer process in Si/Ge superlattices, are studied by analyzing the trajectories generated by the ab initio Car-Parrinello molecular dynamics simulation. The radial distribution functions and mean square displacements are calculated and further discussions are made to explain and probe the structural changes relating to the heat transfer phenomenon. Furthermore, the vibrational density of states of the two layers (Si/Ge) ar...

  6. An Automatic Control System for Conditioning 30 GHz Accelerating Structures

    CERN Document Server

    Dubrovskiy, A

    2008-01-01

    A software application programme has been developed to allow fast and automatic high-gradient conditioning of accelerating structures at 30 GHz in CTF3. The specificity of the application is the ability to control the high-power electron beam which produces the 30 GHz RF power used to condition the accelerating structures. The programme permits operation round the clock with minimum manpower requirements. In this paper the fast control system, machine control system, logging system, graphical user control interface and logging data visualization are described. An outline of the conditioning control system itself and of the feedback controlling peak power and pulse length is given. The software allows different types of conditioning strategies to be programmed

  7. Effect of high temperature annealing on the thermoelectric properties of GaP doped SiGe

    Science.gov (United States)

    Vandersande, Jan W.; Wood, Charles; Draper, Susan

    1987-01-01

    Silicon-germanium alloys doped with GaP are used for thermoelectric energy conversion in the temperature range 300-1000 C. The conversion efficiency depends on Z = S-squared/rho lambda, a material's parameter (the figure of merit), where S is the Seebeck coefficient, rho is the electrical resistivity and lambda is the thermal conductivity. The annealing of several samples in the temperature range of 1100-1300 C resulted in the power factor P (= S-squared/rho) increasing with increased annealing temperature. This increase in P was due to a decrease in rho which was not completely offset by a drop in S-squared suggesting that other changes besides that in the carrier concentration took place. SEM and EDX analysis of the samples indicated the formation of a Ga-P-Ge rich phase as a result of the annealing. It is speculated that this phase is associated with the improved properties. Several reasons which could account for the improvement in the power factor of annealed GaP doped SiGe are given.

  8. Measurement, modeling, and simulation of cryogenic SiGe HBT amplifier circuits for fast single spin readout

    Science.gov (United States)

    England, Troy; Curry, Matthew; Carr, Steve; Swartzentruber, Brian; Lilly, Michael; Bishop, Nathan; Carrol, Malcolm

    2015-03-01

    Fast, low-power quantum state readout is one of many challenges facing quantum information processing. Single electron transistors (SETs) are potentially fast, sensitive detectors for performing spin readout of electrons bound to Si:P donors. From a circuit perspective, however, their output impedance and nonlinear conductance are ill suited to drive the parasitic capacitance typical of coaxial conductors used in cryogenic environments, necessitating a cryogenic amplification stage. We will discuss calibration data, as well as modeling and simulation of cryogenic silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) circuits connected to a silicon SET and operating at 4 K. We find a continuum of solutions from simple, single-HBT amplifiers to more complex, multi-HBT circuits suitable for integration, with varying noise levels and power vs. bandwidth tradeoffs. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

  9. An integrated 12.5-Gb/s optoelectronic receiver with a silicon avalanche photodetector in standard SiGe BiCMOS technology.

    Science.gov (United States)

    Youn, Jin-Sung; Lee, Myung-Jae; Park, Kang-Yeob; Rücker, Holger; Choi, Woo-Young

    2012-12-17

    An optoelectronic integrated circuit (OEIC) receiver is realized with standard 0.25-μm SiGe BiCMOS technology for 850-nm optical interconnect applications. The OEIC receiver consists of a Si avalanche photodetector, a transimpedance amplifier with a DC-balanced buffer, a tunable equalizer, and a limiting amplifier. The fabricated OEIC receiver successfully detects 12.5-Gb/s 2(31)-1 pseudorandom bit sequence optical data with the bit-error rate less than 10(-12) at incident optical power of -7 dBm. The OEIC core has 1000 μm x 280 μm chip area, and consumes 59 mW from 2.5-V supply. To the best of our knowledge, this OEIC receiver achieves the highest data rate with the smallest sensitivity as well as the best power efficiency among integrated OEIC receivers fabricated with standard Si technology.

  10. Performance Analysis of OFDM 60GHz System and SC-FDE 60GHz System

    Directory of Open Access Journals (Sweden)

    Han Xueyan

    2016-01-01

    Full Text Available In this paper, the performance of 60GHz wireless communication system with SC and OFDM is studied, the models of OFDM 60GHz system and SC 60GHz frequency domain equalization (SC-FDE system are established, and the bit error rate (BER performance of OFDM 60GHz system and SC-FDE 60GHz system in 802.15.3c channels is compared. The simulation results show that SC-FDE 60GHz system has a slight advantage over OFDM system in line-of-sight (LOS channels, while OFDM 60GHz system has a slight advantage over SC-FDE system in non-line-of-sight (NLOS channels. For 60GHz system, OFDM 60GHz system has a slight advantage over SC-FDE system in overcoming multipath fading, but the performance of both is close whether in the LOS or NLOS case.

  11. Fabrication of SGOI material by oxidation of an epitaxial SiGe layer on an SOI wafer with H ions implantation

    International Nuclear Information System (INIS)

    Cheng Xinli; Chen Zhijun; Wang Yongjin; Jin Bo; Zhang Feng; Zou Shichang

    2005-01-01

    SGOI materials were fabricated by thermal dry oxidation of epitaxial H-ion implanted SiGe layers on SOI wafers. The hydrogen implantation was found to delay the oxidation rate of SiGe layer and to decrease the loss of Ge atoms during oxidation. Further, the H implantation did not degrade the crystallinity of SiGe layer during fabrication of the SGOI

  12. Critical Role of a Single Position in the −35 Element for Promoter Recognition by Mycobacterium tuberculosis SigE and SigH▿

    OpenAIRE

    Song, Taeksun; Song, Seung-Eun; Raman, Sahadevan; Anaya, Mauricio; Husson, Robert N.

    2008-01-01

    Mycobacterial SigE and SigH both initiate transcription from the sigB promoter, suggesting that they recognize similar sequences. Through mutational and primer extension analyses, we determined that SigE and SigH recognize nearly identical promoters, with differences at the 3′ end of the −35 element distinguishing between SigE- and SigH-dependent promoters.

  13. Significant reduction of thermal conductivity in Si/Ge core-shell nanowires.

    Science.gov (United States)

    Hu, Ming; Giapis, Konstantinos P; Goicochea, Javier V; Zhang, Xiaoliang; Poulikakos, Dimos

    2011-02-09

    We report on the effect of germanium (Ge) coatings on the thermal transport properties of silicon (Si) nanowires using nonequilibrium molecular dynamics simulations. Our results show that a simple deposition of a Ge shell of only 1 to 2 unit cells in thickness on a single crystalline Si nanowire can lead to a dramatic 75% decrease in thermal conductivity at room temperature compared to an uncoated Si nanowire. By analyzing the vibrational density states of phonons and the participation ratio of each specific mode, we demonstrate that the reduction in the thermal conductivity of Si/Ge core-shell nanowire stems from the depression and localization of long-wavelength phonon modes at the Si/Ge interface and of high frequency nonpropagating diffusive modes.

  14. Strain-induced formation of fourfold symmetric SiGe quantum dot molecules.

    Science.gov (United States)

    Zinovyev, V A; Dvurechenskii, A V; Kuchinskaya, P A; Armbrister, V A

    2013-12-27

    The strain field distribution at the surface of a multilayer structure with disklike SiGe nanomounds formed by heteroepitaxy is exploited to arrange the symmetric quantum dot molecules typically consisting of four elongated quantum dots ordered along the [010] and [100] directions. The morphological transition from fourfold quantum dot molecules to continuous fortresslike quantum rings with an increasing amount of deposited Ge is revealed. We examine key mechanisms underlying the formation of lateral quantum dot molecules by using scanning tunneling microscopy and numerical calculations of the strain energy distribution on the top of disklike SiGe nanomounds. Experimental data are well described by a simple thermodynamic model based on the accurate evaluation of the strain dependent part of the surface chemical potential. The spatial arrangement of quantum dots inside molecules is attributed to the effect of elastic property anisotropy.

  15. Nitride passivation of the interface between high-k dielectrics and SiGe

    Energy Technology Data Exchange (ETDEWEB)

    Sardashti, Kasra [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358 (United States); Materials Science and Engineering Program, University of California, San Diego, La Jolla, California 92093-0411 (United States); Hu, Kai-Ting [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358 (United States); Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, California 92093-0411 (United States); Tang, Kechao; McIntyre, Paul [Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 (United States); Madisetti, Shailesh; Oktyabrsky, Serge [Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, New York 12222 (United States); Siddiqui, Shariq; Sahu, Bhagawan [TD Research, GLOBALFOUNDRIES US, Inc., Albany, New York 12203 (United States); Yoshida, Naomi; Kachian, Jessica; Dong, Lin [Applied Materials, Inc., Santa Clara, California 95054 (United States); Fruhberger, Bernd [California Institute for Telecommunications and Information Technology, University of California San Diego, La Jolla, California 92093-0436 (United States); Kummel, Andrew C., E-mail: akummel@ucsd.edu [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358 (United States)

    2016-01-04

    In-situ direct ammonia (NH{sub 3}) plasma nitridation has been used to passivate the Al{sub 2}O{sub 3}/SiGe interfaces with Si nitride and oxynitride. X-ray photoelectron spectroscopy of the buried Al{sub 2}O{sub 3}/SiGe interface shows that NH{sub 3} plasma pre-treatment should be performed at high temperatures (300 °C) to fully prevent Ge nitride and oxynitride formation at the interface and Ge out-diffusion into the oxide. C-V and I-V spectroscopy results show a lower density of interface traps and smaller gate leakage for samples with plasma nitridation at 300 °C.

  16. Diffusion of $^{56}$Co in GaAs and SiGe alloys

    CERN Multimedia

    Koskelo, O K

    2007-01-01

    Following our previous diffusion studies performed with the modified radiotracer technique, we propose to determine the diffusion of cobalt in GaAs and SiGe alloys under intrinsic conditions. In the literature only three previous studies for Co diffusion in GaAs may be found and the results differ by over four orders of magnitude from each other. For Co diffusion in SiGe alloys no previous data is available in the literature. For Co diffusion in Ge one study may be found but the results have been obtained with material having increased dislocation density. For dislocation-free material no previous measurements are available. For such experiments we ask for two runs of 3 shifts (total of 6 shifts) with $^{56}$Co$^{+}$ ion beam.

  17. Experimental study of a 1 MW, 170 GHz gyrotron oscillator

    Science.gov (United States)

    Kimura, Takuji

    A detailed experimental study is presented of a 1 MW, 170 GHz gyrotron oscillator whose design is consistent with the ECH requirements of the International Thermonuclear Experimental Reactor (ITER) for bulk heating and current drive. This work is the first to demonstrate that megawatt power level at 170 GHz can be achieved in a gyrotron with high efficiency for plasma heating applications. Maximum output power of 1.5 MW is obtained at 170.1 GHz in 85 kV, 50A operation for an efficiency of 35%. Although the experiment at MIT is conducted with short pulses (3 μs), the gyrotron is designed to be suitable for development by industry for continuous wave operation. The peak ohmic loss on the cavity wall for 1 MW of output power is calculated to be 2.3 kW/cm2, which can be handled using present cooling technology. Mode competition problems in a highly over-moded cavity are studied to maximize the efficiency. Various aspects of electron gun design are examined to obtain high quality electron beams with very low velocity spread. A triode magnetron injection gun is designed using the EGUN simulation code. A total perpendicular velocity spread of less than 8% is realized by designing a low- sensitivity, non-adiabatic gun. The RF power is generated in a short tapered cavity with an iris step. The operating mode is the TE28,8,1 mode. A mode converter is designed to convert the RF output to a Gaussian beam. Power and efficiency are measured in the design TE28,8,1 mode at 170.1 GHz as well as the TE27,8,1 mode at 166.6 GHz and TE29,8,1 mode at 173.5 GHz. Efficiencies between 34%-36% are consistently obtained over a wide range of operating parameters. These efficiencies agree with the highest values predicted by the multimode simulations. The startup scenario is investigated and observed to agree with the linear theory. The measured beam velocity ratio is consistent with EGUN simulation. Interception of reflected beam by the mod-anode is measured as a function of velocity ratio

  18. Integrated X-band FMCW front-end in SiGe BiCMOS

    NARCIS (Netherlands)

    Suijker, Erwin; de Boer, Lex; Visser, Guido; van Dijk, Raymond; Poschmann, Michael; van Vliet, Frank Edward

    2010-01-01

    An integrated X-band FMCW front-end is reported. The front-end unites the core functionality of an FMCW transmitter and receiver in a 0.25 μm SiGe BiCMOS process. The chip integrates a PLL for the carrier generation, and single-side band and image-reject mixers for up- and down-conversion of the

  19. Step-driven surface segregation and ordering during Si-Ge MBE growth

    International Nuclear Information System (INIS)

    Jesson, D.E.; Pennycook, S.J.; Baribeau, J.M.; Houghton, D.C.

    1992-06-01

    An important role of type S B step edges in determining the as-grown microstructure of Si-Ge superlattices and alloys is implicated from direct Z-contrast images of as-grown structures. A variety of different ordered phase variants can arise at each Si on Ge interface as a result of vertical segregation during superlattice growth. A new monoclinic-ordered structure is predicted to arise as a result of lateral segregation during alloy growth

  20. Wireless powering for low-power distributed sensors

    Directory of Open Access Journals (Sweden)

    Popović Zoya B.

    2006-01-01

    Full Text Available In this paper, an overview of the field of wireless powering is presented with an emphasis on low-power applications. Several rectenna elements and arrays are discussed in more detail: (1 a 10-GHz array for powering sensors in aircraft wings; (2 a single antenna in the 2.4-GHz ISM band for low-power assisted-living sensors; and (3 a broadband array for power harvesting in the 2-18GHz frequency range.

  1. SiGe derivatization by spontaneous reduction of aryl diazonium salts

    Science.gov (United States)

    Girard, A.; Geneste, F.; Coulon, N.; Cardinaud, C.; Mohammed-Brahim, T.

    2013-10-01

    Germanium semiconductors have interesting properties for FET-based biosensor applications since they possess high surface roughness allowing the immobilization of a high amount of receptors on a small surface area. Since SiGe combined low cost of Si and intrinsic properties of Ge with high mobility carriers, we focused the study on this particularly interesting material. The comparison of the efficiency of a functionalization process involving the spontaneous reduction of diazonium salts is studied on Si(1 0 0), SiGe and Ge semiconductors. XPS analysis of the functionalized surfaces reveals the presence of a covalent grafted layer on all the substrates that was confirmed by AFM. Interestingly, the modified Ge derivatives have still higher surface roughness after derivatization. To support the estimated thickness by XPS, a step measurement of the organic layers is done by AFM or by profilometer technique after a O2 plasma etching of the functionalized layer. This original method is well-adapted to measure the thickness of thin organic films on rough substrates such as germanium. The analyses show a higher chemical grafting on SiGe substrates compared with Si and Ge semiconductors.

  2. Raman and photoluminescence spectroscopy of SiGe layer evolution on Si(100) induced by dewetting

    Science.gov (United States)

    Shklyaev, A. A.; Volodin, V. A.; Stoffel, M.; Rinnert, H.; Vergnat, M.

    2018-01-01

    High temperature annealing of thick (40-100 nm) Ge layers deposited on Si(100) at ˜400 °C leads to the formation of continuous films prior to their transformation into porous-like films due to dewetting. The evolution of Si-Ge composition, lattice strain, and surface morphology caused by dewetting is analyzed using scanning electron microscopy, Raman, and photoluminescence (PL) spectroscopies. The Raman data reveal that the transformation from the continuous to porous film proceeds through strong Si-Ge interdiffusion, reducing the Ge content from 60% to about 20%, and changing the stress from compressive to tensile. We expect that Ge atoms migrate into the Si substrate occupying interstitial sites and providing thereby the compensation of the lattice mismatch. Annealing generates only one type of radiative recombination centers in SiGe resulting in a PL peak located at about 0.7 and 0.8 eV for continuous and porous film areas, respectively. Since annealing leads to the propagation of threading dislocations through the SiGe/Si interface, we can tentatively associate the observed PL peak to the well-known dislocation-related D1 band.

  3. Stress-directed compositional patterning of SiGe substrates for lateral quantum barrier manipulation

    International Nuclear Information System (INIS)

    Ghosh, Swapnadip; Kaiser, Daniel; Sinno, Talid; Bonilla, Jose; Han, Sang M.

    2015-01-01

    While vertical stacking of quantum well and dot structures is well established in heteroepitaxial semiconductor materials, manipulation of quantum barriers in the lateral directions poses a significant engineering challenge. Here, we demonstrate lateral quantum barrier manipulation in a crystalline SiGe alloy using structured mechanical fields to drive compositional redistribution. To apply stress, we make use of a nano-indenter array that is pressed against a Si 0.8 Ge 0.2 wafer in a custom-made mechanical press. The entire assembly is then annealed at high temperatures, during which the larger Ge atoms are selectively driven away from areas of compressive stress. Compositional analysis of the SiGe substrates reveals that this approach leads to a transfer of the indenter array pattern to the near-surface elemental composition, resulting in near 100% Si regions underneath each indenter that are separated from each other by the surrounding Si 0.8 Ge 0.2 bulk. The “stress transfer” process is studied in detail using multiscale computer simulations that demonstrate its robustness across a wide range of applied stresses and annealing temperatures. While the “Si nanodot” structures formed here are not intrinsically useful as quantum structures, it is anticipated that the stress transfer process may be modified by judicious control of the SiGe film thickness and indenter array pattern to form more technologically useful structures

  4. Interfacial Phonon Transport Through Si/Ge Multilayer Film Using Monte Carlo Scheme With Spectral Transmissivity

    Directory of Open Access Journals (Sweden)

    Xin Ran

    2018-05-01

    Full Text Available The knowledge of interfacial phonon transport accounting for detailed phonon spectral properties is desired because of its importance for design of nanoscale energy systems. In this work, we investigate the interfacial phonon transport through Si/Ge multilayer films using an efficient Monte Carlo scheme with spectral transmissivity, which is validated for cross-plane phonon transport through both Si/Ge single-layer and Si/Ge bi-layer thin films by comparing with the discrete-ordinates solution. Different thermal boundary conductances between even the same material pair are declared at different interfaces within the multilayer system. Furthermore, the thermal boundary conductances at different interfaces show different trends with varying total system size, with the variation slope, very different as well. The results are much different from those in the bi-layer thin film or periodic superlattice. These unusual behaviors can be attributed to the combined interfacial local non-equilibrium effect and constraint effect from other interfaces.

  5. Ion beam analysis of the dry thermal oxidation of thin polycrystalline SiGe films

    International Nuclear Information System (INIS)

    Kling, A.; Soares, J.C.; Prieto, A.C.; Jimenez, J.; Rodriguez, A.; Sangrador, J.; Rodriguez, T.

    2005-01-01

    Nanoparticles of Ge embedded in a formed dielectric matrix appear as very promising systems for electronic and photonic applications. We present here an exhaustive characterization of the oxidation process of polycrystalline SiGe layers from the starting of its oxidation process to the total oxidation of it. We have characterized the process by RBS, FTIR and Raman spectroscopy, showing the necessity to use different techniques in order to get a full view of the process. First the Si-Si and Si-Ge bonds are oxidized growing SiO 2 , and Ge segregates from the SiO 2 . As soon as all Si is oxidized GeO 2 is growing gradually. RBS has demonstrated to be very useful to characterize the SiO 2 and the remaining non-oxidized poly-SiGe layer thickness, as well as for the determination of the Ge fraction, where the high sensitivity of this technique allows to explore its whole range. On the other hand, for the reliable determination of the GeO 2 thickness, information on the amount of Ge-O bonding had to be obtained from FTIR spectra. Raman spectroscopy yields detailed information about the oxidation processes for different bonds (Si-Si, Si-Ge, Ge-Ge)

  6. 154 GHz collective Thomson scattering in LHD

    Science.gov (United States)

    Tanaka, K.; Nishiura, M.; Kubo, S.; Shimozuma, T.; Saito, T.; Moseev, D.; Abramovic, I.

    2018-01-01

    Collective Thomson scattering (CTS) was developed by using a 154 GHz gyrotron, and the first data has been obtained. Already, 77 GHz CTS has worked successfully. However, in order to access higher density region, 154 GHz option enhances the usability that reduces the refraction effect, which deteriorates in the local measurements. The system in the down converted frequency was almost identical to the system for 77 GHz. Probing beam, a notch filter, a mixer, and a local oscillator in the receiver system for 77 GHz option were replaced to those for the 154 GHz option. 154 GHz gyrotron was originally prepared for the second harmonic electron cyclotron heating (ECRH) at 2.75 T. However, scattering signal was masked by the second harmonic electron cyclotron emission (ECE) at 2.75 T. Therefore, 154 GHz CTS was operated at 1.375 T with fourth harmonic ECE, and an acceptable signal to noise ratio was obtained. There is a signature of fast ion components with neutral beam (NB) injection. In addition, the CTS spectrum became broader in hydrogen discharge than in deuterium discharge, as the theoretical CTS spectrum expects. This observation indicates a possibility to identify ion species ratio by the 154 GHz CTS diagnostic.

  7. A 2 MW, CW, 170 GHz gyrotron for ITER

    International Nuclear Information System (INIS)

    Piosczyk, B.; Arnold, A.; Alberti, S.

    2003-01-01

    A 140 GHz gyrotron for CW operation is under development for the stellarator W7-X. With a prototype tube a microwave output power of about 0.9 MW has been obtained in pulses up to 180 s, limited by the capability of the high voltage power supply. The development work on coaxial cavity gyrotrons has demonstrated the feasibility of manufacturing of a 2 MW, CW 170 GHz tube that could be used for ITER. The problems specific to the coaxial arrangement have been investigated and all relevant information needed for an industrial realization of a coaxial gyrotron have been obtained in short pulse experiments (up to 17 ms). The suitability of critical components for a 2 MW, CW coaxial gyrotron has been studied and a first integrated design has been done. (author)

  8. 100 GHz, 1 MW, CW gyrotron study program. Final report

    International Nuclear Information System (INIS)

    Felch, K.; Bier, R.; Caplan, M.; Jory, H.

    1983-09-01

    The results of a study program to investigate the feasibility of various approaches in designing a 100 GHz, 1 MW CW gyrotron are presented. A summary is given of the possible configurations for a high average power, high frequency gyrotron, including an historical survey of experimental results which are relevant to the various approaches. A set of basic scaling considerations which enable qualitative comparisons between particular gyrotron interaction circuits is presented. These calculations are important in understanding the role of various electron beam and circuit parameters in achieving a viable gyrotron design. Following these scaling exercises, a series of design calculations is presented for a possible approach in achieving 100 GHz, 1 MW CW. These calculations include analyses of the electron gun and interaction circuit parts of the gyrotron, and a general analysis of other aspects of a high average power, high frequency gyrotron. Scalability of important aspects of the design to other frequencies is also discussed, as well as key technology issues

  9. Future mobile satellite communication concepts at 20/30 GHz

    Science.gov (United States)

    Barton, S. K.; Norbury, J. R.

    1990-01-01

    The outline of a design of a system using ultra small earth stations (picoterminals) for data traffic at 20/30 GHz is discussed. The picoterminals would be battery powered, have an RF transmitter power of 0.5 W, use a 10 cm square patch antenna, and have a receiver G/T of about -8 dB/K. Spread spectrum modulation would be required (due to interference consideration) to allow a telex type data link (less than 200 bit/s data rate) from the picoterminal to the hub station of the network and about 40 kbit/s on the outbound patch. An Olympus type transponder at 20/30 GHz could maintain several thousand simultaneous picoterminal circuits. The possibility of demonstrating a picoterminal network with voice traffic using Olympus is discussed together with fully mobile systems based on this concept.

  10. Entanglement swapping of a GHZ state via a GHZ-like state

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Chia-Wei; Hwang, Tzonelih, E-mail: hwangtl@ismail.csie.ncku.edu.t [National Cheng Kung University, Department of Computer Science and Information Engineering, No. 1 Ta-Hsueh Road, Tainan City 701, Taiwan (China)

    2011-10-15

    This study uses the Greenberger-Horne-Zeilinger (GHZ)-like state |G>= 1/2 (|001>+|010>+|100>+|111>) to establish an entanglement swapping protocol on a pure GHZ state. A quantum circuit is proposed to assist in teleporting the entanglement of the pure GHZ state. Furthermore, on the basis of the generation of the GHZ-like state, an improved protocol to reduce the number of transmitted photons required in the process of entanglement swapping is proposed.

  11. SiGe layer thickness effect on the structural and optical properties of well-organized SiGe/SiO2 multilayers

    Science.gov (United States)

    Vieira, E. M. F.; Toudert, J.; Rolo, A. G.; Parisini, A.; Leitão, J. P.; Correia, M. R.; Franco, N.; Alves, E.; Chahboun, A.; Martín-Sánchez, J.; Serna, R.; Gomes, M. J. M.

    2017-08-01

    In this work, we report on the production of regular (SiGe/SiO2)20 multilayer structures by conventional RF-magnetron sputtering, at 350 °C. Transmission electron microscopy, scanning transmission electron microscopy, raman spectroscopy, and x-ray reflectometry measurements revealed that annealing at a temperature of 1000 °C leads to the formation of SiGe nanocrystals between SiO2 thin layers with good multilayer stability. Reducing the nominal SiGe layer thickness (t SiGe) from 3.5-2 nm results in a transition from continuous SiGe crystalline layer (t SiGe ˜ 3.5 nm) to layers consisting of isolated nanocrystals (t SiGe ˜ 2 nm). Namely, in the latter case, the presence of SiGe nanocrystals ˜3-8 nm in size, is observed. Spectroscopic ellipsometry was applied to determine the evolution of the onset in the effective optical absorption, as well as the dielectric function, in SiGe multilayers as a function of the SiGe thickness. A clear blue-shift in the optical absorption is observed for t SiGe ˜ 2 nm multilayer, as a consequence of the presence of isolated nanocrystals. Furthermore, the observed near infrared values of n = 2.8 and k = 1.5 are lower than those of bulk SiGe compounds, suggesting the presence of electronic confinement effects in the nanocrystals. The low temperature (70 K) photoluminescence measurements performed on annealed SiGe/SiO2 nanostructures show an emission band located between 0.7-0.9 eV associated with the development of interface states between the formed nanocrystals and surrounding amorphous matrix.

  12. CARM and harmonic gyro-amplifier experiments at 17 GHz

    International Nuclear Information System (INIS)

    Menninger, W.L.; Danly, B.G.; Alberti, S.; Chen, C.; Rullier, J.L.; Temkin, R.J.

    1993-01-01

    Cyclotron resonance maser amplifiers are possible sources for applications such as electron cyclotron resonance heating of fusion plasmas and driving high-gradient rf linear accelerators. For accelerator drivers, amplifiers or phase locked-oscillators are required. A 17 GHz cyclotron autoresonance maser (CARM) amplifier experiment and a 17 GHz third harmonic gyro-amplifier experiment are presently underway at the MIT Plasma Fusion Center. Using the SRL/MIT SNOMAD II introduction accelerator to provide a 380 kV, 180 A, 30 ns flat top electron beam, the gyro-amplifier experiment has produced 5 MW of rf power with over 50 dB of gain at 17 GHz. The gyro-amplifier operates in the TE 31 mode using a third harmonic interaction. Because of its high power output, the gyro-amplifier will be used as the rf source for a photocathode rf electron gun experiment also taking place at MIT. Preliminary gyro-amplifier results are presented, including measurement of rf power, gain versus interaction length, and the far-field pattern. A CARM experiment designed to operate in the TE 11 mode is also discussed

  13. Design of a 17.14 GHz quasi-optical pulse compressor

    International Nuclear Information System (INIS)

    Petelin, M. I.; Kuzikov, S. V.; Danilov, Yu. Yu.; Granatstein, V. L.; Nusinovich, G. S.

    1999-01-01

    A quasi-optical version of the ring cavity pulse compressor is considered. This concept is based on the coupling of the input wave to a whispering gallery mode of a barrel-like cavity due to helical corrugations of the cavity wall. Low-power tests of the prototype were carried out at 11.4 GHz and demonstrated reasonable agree-ment between experimental data and theoretical predictions. The design of a similar pulse compressor at 17.14 GHz compatible with the 17.14 GHz, 100 MW gyroklystron currently under development at the University of Maryland is presented

  14. sigE facilitates the adaptation of Bordetella bronchiseptica to stress conditions and lethal infection in immunocompromised mice

    Directory of Open Access Journals (Sweden)

    Barchinger Sarah E

    2012-08-01

    Full Text Available Abstract Background The cell envelope of a bacterial pathogen can be damaged by harsh conditions in the environment outside a host and by immune factors during infection. Cell envelope stress responses preserve the integrity of this essential compartment and are often required for virulence. Bordetella species are important respiratory pathogens that possess a large number of putative transcription factors. However, no cell envelope stress responses have been described in these species. Among the putative Bordetella transcription factors are a number of genes belonging to the extracytoplasmic function (ECF group of alternative sigma factors, some of which are known to mediate cell envelope stress responses in other bacteria. Here we investigate the role of one such gene, sigE, in stress survival and pathogenesis of Bordetella bronchiseptica. Results We demonstrate that sigE encodes a functional sigma factor that mediates a cell envelope stress response. Mutants of B. bronchiseptica strain RB50 lacking sigE are more sensitive to high temperature, ethanol, and perturbation of the envelope by SDS-EDTA and certain β-lactam antibiotics. Using a series of immunocompromised mice deficient in different components of the innate and adaptive immune responses, we show that SigE plays an important role in evading the innate immune response during lethal infections of mice lacking B cells and T cells. SigE is not required, however, for colonization of the respiratory tract of immunocompetent mice. The sigE mutant is more efficiently phagocytosed and killed by peripheral blood polymorphonuclear leukocytes (PMNs than RB50, and exhibits decreased cytotoxicity toward macrophages. These altered interactions with phagocytes could contribute to the defects observed during lethal infection. Conclusions Much of the work on transcriptional regulation during infection in B. bronchiseptica has focused on the BvgAS two-component system. This study reveals that the SigE

  15. Unlocking the Origin of Superior Performance of a Si-Ge Core-Shell Nanowire Quantum Dot Field Effect Transistor.

    Science.gov (United States)

    Dhungana, Kamal B; Jaishi, Meghnath; Pati, Ranjit

    2016-07-13

    The sustained advancement in semiconducting core-shell nanowire technology has unlocked a tantalizing route for making next generation field effect transistor (FET). Understanding how to control carrier mobility of these nanowire channels by applying a gate field is the key to developing a high performance FET. Herein, we have identified the switching mechanism responsible for the superior performance of a Si-Ge core-shell nanowire quantum dot FET over its homogeneous Si counterpart. A quantum transport approach is used to investigate the gate-field modulated switching behavior in electronic current for ultranarrow Si and Si-Ge core-shell nanowire quantum dot FETs. Our calculations reveal that for the ON state, the gate-field induced transverse localization of the wave function restricts the carrier transport to the outer (shell) layer with the pz orbitals providing the pathway for tunneling of electrons in the channels. The higher ON state current in the Si-Ge core-shell nanowire FET is attributed to the pz orbitals that are distributed over the entire channel; in the case of Si nanowire, the participating pz orbital is restricted to a few Si atoms in the channel resulting in a smaller tunneling current. Within the gate bias range considered here, the transconductance is found to be substantially higher in the case of a Si-Ge core-shell nanowire FET than in a Si nanowire FET, which suggests a much higher mobility in the Si-Ge nanowire device.

  16. GHz band frequency hopping PLL-based frequency synthesizers

    Institute of Scientific and Technical Information of China (English)

    XU Yong; WANG Zhi-gong; GUAN Yu; XU Zhi-jun; QIAO Lu-feng

    2005-01-01

    In this paper we describe a full-integrated circuit containing all building blocks of a completed PLL-based synthesizer except for low pass filter(LPF).The frequency synthesizer is designed for a frequency hopping (FH) transceiver operating up to 1.5 GHz as a local oscillator. The architecture of Voltage Controlled Oscillator (VCO) is optimized to get better performance, and a phase noise of -111.85-dBc/Hz @ 1 MHz and a tuning range of 250 MHz are gained at a centre frequency of 1.35 GHz.A novel Dual-Modulus Prescaler(DMP) is designed to achieve a very low jitter and a lower power.The settling time of PLL is 80 μs while the reference frequency is 400 KHz.This monolithic frequency synthesizer is to integrate all main building blocks of PLL except for the low pass filter,with a maximum VCO output frequency of 1.5 GHz,and is fabricated with a 0.18 μm mixed signal CMOS process. Low power dissipation, low phase noise, large tuning range and fast settling time are gained in this design.

  17. Molecular Spectroscopy With a Compact 557-GHz Heterodyne Receiver

    DEFF Research Database (Denmark)

    Neumaier, Philipp F.-X.; Richter, Heiko; Stake, Jan

    2014-01-01

    We report on a heterodyne terahertz spectrometer based on a fully integrated 557-GHz receiver and a digital fast Fourier transform spectrometer. The receiver consists of a chain of multipliers and power amplifiers, followed by a heterostructure barrier varactor tripler that subharmonically pumps...... a membrane GaAs Schottky diode mixer. All sub-components are newly developed and optimized with regard to the overall receiver performance such as noise temperature, power consumption, weight and physical size. The receiver works at room temperature, has a double sideband noise temperature as low as 2000 K...

  18. 280 GHz Gyro-BWO design study: Final report

    International Nuclear Information System (INIS)

    1988-07-01

    This report summarizes the results of a design study of a 280 GHz Gyro-BWO tunable source. The purpose of this study is to identify and propose viable design alternatives for any significant technological risk associated with building an operational BWO system. The tunable Gyro-BWO system will have three major components: a Gyro-BWO microwave tube, a superconducting magnet, and a power supply/modulator. The design tasks for this study in order of decreasing importance are: design and specification of the superconducting magnet; preliminary design and layout of a Gyro-BWO microwave tube; and specification for the power supply/modulator. 2 refs., 4 figs

  19. Design of 20-44 GHz broadband doubler MMIC

    International Nuclear Information System (INIS)

    Li Qin; Wang Zhigong; Li Wei

    2010-01-01

    This paper presents the design and performance of a broadband millimeter-wave frequency doubler MMIC using active 0.15 μm GaAs PHEMT and operating at output frequencies from 20 to 44 GHz. This chip is composed of a single ended-into differential-out active Balun, balanced FETs in push-push configuration, and a distributed amplifier. The MMIC doubler exhibits more than 4 dB conversion gain with 12 dBm of output power, and the fundamental frequency suppression is typically -20 dBc up to 44 GHz. The MMIC works at V DD = 3.5 V, V SS = -3.5 V, I d = 200 mA and the chip size is 1.5 x 1.8 mm 2 . (semiconductor integrated circuits)

  20. Ge nanobelts with high compressive strain fabricated by secondary oxidation of self-assembly SiGe rings

    DEFF Research Database (Denmark)

    Lu, Weifang; Li, Cheng; Lin, Guangyang

    2015-01-01

    Curled Ge nanobelts were fabricated by secondary oxidation of self-assembly SiGe rings, which were exfoliated from the SiGe stripes on the insulator. The Ge-rich SiGe stripes on insulator were formed by hololithography and modified Ge condensation processes of Si0.82Ge0.18 on SOI substrate. Ge...... nanobelts under a residual compressive strain of 2% were achieved, and the strain should be higher before partly releasing through bulge islands and breakage of the curled Ge nanobelts during the secondary oxidation process. The primary factor leading to compressive strain is thermal shrinkage of Ge...... nanobelts, which extrudes to Ge nanobelts in radial and tangent directions during the cooling process. This technique is promising for application in high-mobility Ge nano-scale transistors...

  1. Characterisation of diode-connected SiGe BiCMOS HBTs for space applications

    Science.gov (United States)

    Venter, Johan; Sinha, Saurabh; Lambrechts, Wynand

    2016-02-01

    Silicon-germanium (SiGe) bipolar complementary metal-oxide semiconductor (BiCMOS) transistors have vertical doping profiles reaching deeper into the substrate when compared to lateral CMOS transistors. Apart from benefiting from high-speed, high current gain and low-output resistance due to its vertical profile, BiCMOS technology is increasingly becoming a preferred technology for researchers to realise next-generation space-based optoelectronic applications. BiCMOS transistors have inherent radiation hardening, to an extent predictable cryogenic performance and monolithic integration potential. SiGe BiCMOS transistors and p-n junction diodes have been researched and used as a primary active component for over the last two decades. However, further research can be conducted with diode-connected heterojunction bipolar transistors (HBTs) operating at cryogenic temperatures. This work investigates these characteristics and models devices by adapting standard fabrication technology components. This work focuses on measurements of the current-voltage relationship (I-V curves) and capacitance-voltage relationships (C-V curves) of diode-connected HBTs. One configuration is proposed and measured, which is emitterbase shorted. The I-V curves are measured for various temperature points ranging from room temperature (300 K) to the temperature of liquid nitrogen (77 K). The measured datasets are used to extract a model of the formed diode operating at cryogenic temperatures and used as a standard library component in computer aided software designs. The advantage of having broad-range temperature models of SiGe transistors becomes apparent when considering implementation of application-specific integrated circuits and silicon-based infrared radiation photodetectors on a single wafer, thus shortening interconnects and lowering parasitic interference, decreasing the overall die size and improving on overall cost-effectiveness. Primary applications include space-based geothermal

  2. Low thermal budget surface preparation of Si and SiGe

    International Nuclear Information System (INIS)

    Abbadie, A.; Hartmann, J.M.; Holliger, P.; Semeria, M.N.; Besson, P.; Gentile, P.

    2004-01-01

    Using a two-step cleaning, we have investigated the low thermal budget surface preparation of Si and Si 1-x Ge x (x=0.2-0.33). It consists of an ex situ 'HF-last' wet-cleaning and an in situ low thermal budget H 2 bake in a reduced pressure-chemical vapor deposition reactor. Using secondary ion mass spectrometry, we have evaluated the effects of different H 2 bake temperatures (in between 750 and 850 deg. C for 2 min) on the removal efficiency of C, O and F atoms still present on the surface of Si and SiGe virtual substrates after the 'HF-last' wet-cleaning. We have then examined the impact of the (wet-cleaning+H 2 bake) combination on the surface cross-hatch of SiGe as-grown virtual substrates, focusing on the analysis, notably by atomic force microscopy, of the surface topography before and after the miscellaneous thermal treatments. In situ hydrogen baking steps in between 775 and 850 deg. C do not modify the surface morphology and roughness. An easy and rapid optical characterization method, i.e. the optical interferometry, is presented as well to monitor in line the morphological changes induced by such processing steps as chemical mechanical polishing, wet-cleaning, H 2 bake, etc. Despite the lower resolution of the optical profilometer, the surface roughness values coming from it have been correctly correlated with those obtained from AFM. An optimized 'HF-last' wet-cleaning using a diluted chemistry in conjunction with a H 2 bake at 800 deg. C for 2 min (775 deg. C, 2') is a good compromise for SiGe (Si) surface preparation

  3. Thermal conductivity engineering of bulk and one-dimensional Si-Ge nanoarchitectures.

    Science.gov (United States)

    Kandemir, Ali; Ozden, Ayberk; Cagin, Tahir; Sevik, Cem

    2017-01-01

    Various theoretical and experimental methods are utilized to investigate the thermal conductivity of nanostructured materials; this is a critical parameter to increase performance of thermoelectric devices. Among these methods, equilibrium molecular dynamics (EMD) is an accurate technique to predict lattice thermal conductivity. In this study, by means of systematic EMD simulations, thermal conductivity of bulk Si-Ge structures (pristine, alloy and superlattice) and their nanostructured one dimensional forms with square and circular cross-section geometries (asymmetric and symmetric) are calculated for different crystallographic directions. A comprehensive temperature analysis is evaluated for selected structures as well. The results show that one-dimensional structures are superior candidates in terms of their low lattice thermal conductivity and thermal conductivity tunability by nanostructuring, such as by diameter modulation, interface roughness, periodicity and number of interfaces. We find that thermal conductivity decreases with smaller diameters or cross section areas. Furthermore, interface roughness decreases thermal conductivity with a profound impact. Moreover, we predicted that there is a specific periodicity that gives minimum thermal conductivity in symmetric superlattice structures. The decreasing thermal conductivity is due to the reducing phonon movement in the system due to the effect of the number of interfaces that determine regimes of ballistic and wave transport phenomena. In some nanostructures, such as nanowire superlattices, thermal conductivity of the Si/Ge system can be reduced to nearly twice that of an amorphous silicon thermal conductivity. Additionally, it is found that one crystal orientation, [Formula: see text]100[Formula: see text], is better than the [Formula: see text]111[Formula: see text] crystal orientation in one-dimensional and bulk SiGe systems. Our results clearly point out the importance of lattice thermal conductivity

  4. Towards rhombohedral SiGe epitaxy on 150mm c-plane sapphire substrates

    Science.gov (United States)

    Duzik, Adam J.; Park, Yeonjoon; Choi, Sang H.

    2015-04-01

    Previous work demonstrated for the first time the ability to epitaxially grow uniform single crystal diamond cubic SiGe (111) films on trigonal sapphire (0001) substrates. While SiGe (111) forms two possible crystallographic twins on sapphire (0001), films consisting primarily of one twin were produced on up to 99.95% of the total wafer area. This permits new bandgap engineering possibilities and improved group IV based devices that can exploit the higher carrier mobility in Ge compared to Si. Models are proposed on the epitaxy of such dissimilar crystal structures based on the energetic favorability of crystallographic twins and surface reconstructions. This new method permits Ge (111) on sapphire (0001) epitaxy, rendering Ge an economically feasible replacement for Si in some applications, including higher efficiency Si/Ge/Si quantum well solar cells. Epitaxial SiGe films on sapphire showed a 280% increase in electron mobility and a 500% increase in hole mobility over single crystal Si. Moreover, Ge possesses a wider bandgap for solar spectrum conversion than Si, while the transparent sapphire substrate permits an inverted device structure, increasing the total efficiency to an estimated 30-40%, much higher than traditional Si solar cells. Hall Effect mobility measurements of the Ge layer in the Si/Ge/Si quantum well structure were performed to demonstrate the advantage in carrier mobility over a pure Si solar cell. Another application comes in the use of microelectromechanical devices technology, where high-resistivity Si is currently used as a substrate. Sapphire is a more resistive substrate and offers better performance via lower parasitic capacitance and higher film carrier mobility over the current Si-based technology.

  5. Magnetic behavior of Si-Ge bond in SixGe4-x nano-clusters

    Science.gov (United States)

    Nahali, Masoud; Mehri, Ali

    2018-06-01

    The structure of SixGe4-x nano-clusters were optimized by MPW1B95 level of theory using MG3S and SDB-aug-cc-PVTZ basis set. The agreement of the calculated ionization and dissociation energies with experimental values validates the reported structures of nano-clusters and justifies the use of hybrid meta density functional method. Since the Si-Si bond is stronger than Si-Ge and Ge-Ge bonds, the Si-Si, Si-Ge, and Ge-Ge diagonal bonds determine the precedence of the stability in these nano-clusters. The hybrid meta density functional calculations were carried out to investigate the adsorption of CO on all possible SixGe4-x nano-clusters. It was found that the silicon atom generally makes a stronger bond with CO than germanium and thereby preferentially affects the shape of structures having higher multiplicity. In Si-Ge structures with higher spin more than 95% of spins accumulate on positions with less bonds to other atoms of the cluster. Through CO adsorption on these clusters bridge structures are made that behave as spin bridge which conduct the spin from the nano-cluster surface to the adsorbate atoms. A better understanding of bridged structures was achieved upon introducing the 'spin bridge' concept. Based on exhaustive spin density analysis, it was found that the reason for the extra negative charge on oxygen in the bridged structures is the relocation of spin from the surface through the bridge.

  6. Design of a 300 GHz Broadband TWT Coupler and RF-Structure

    CERN Document Server

    Krawczyk, F L

    2004-01-01

    Recent LANL activities in millimeter wave structures focus on 94 and 300 GHz structures. They aim at power generation from low power (100–2000 W) with a round electron beam (120 kV, 0.1–1.0 A) to high power (2–100 kW) with a sheet beam structure (120 kV, 20 A). Applications cover basic research, radar and secure communications and remote sensing of biological and chemical agents. In this presentation the design and cold-test measurements of a 300 GHz RF-structure with a broadband (>6% bandwidth) power coupler are presented. The design choice of two input/output waveguides, a special coupling region and the structure parameters themselves are presented. As a benchmark also a scaled up version at 10 GHz was designed and measured. These results will also be presented.

  7. Gas cluster ion beam assisted NiPt germano-silicide formation on SiGe

    Energy Technology Data Exchange (ETDEWEB)

    Ozcan, Ahmet S., E-mail: asozcan@us.ibm.com [IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120 (United States); Lavoie, Christian; Jordan-Sweet, Jean [IBM T. J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, New York 10598 (United States); Alptekin, Emre; Zhu, Frank [IBM Semiconductor Research and Development Center, 2070 Route 52, Hopewell Junction, New York 12533 (United States); Leith, Allen; Pfeifer, Brian D.; LaRose, J. D.; Russell, N. M. [TEL Epion Inc., 900 Middlesex Turnpike, Bldg. 6, Billerica, Massachusetts 01821 (United States)

    2016-04-21

    We report the formation of very uniform and smooth Ni(Pt)Si on epitaxially grown SiGe using Si gas cluster ion beam treatment after metal-rich silicide formation. The gas cluster ion implantation process was optimized to infuse Si into the metal-rich silicide layer and lowered the NiSi nucleation temperature significantly according to in situ X-ray diffraction measurements. This novel method which leads to more uniform films can also be used to control silicide depth in ultra-shallow junctions, especially for high Ge containing devices, where silicidation is problematic as it leads to much rougher interfaces.

  8. A note on the Sumerian expression SI-ge4-de3/dam

    Directory of Open Access Journals (Sweden)

    Widell, Magnus

    2002-12-01

    Full Text Available The expression SI-ge4-dam/de3 appears in some of the loan documents of the Ur III period where it was used to establish the interest rate or the loan fee. In addition, it is sometimes preceded by ki-ba 'in its/this place/ground' or, in some cases, ma2 -a 'in the boat'. The regular verb SI.g was closely related, perhaps even synonymous with, the reduplication verb ḡar/ḡa2-ḡa2 'to put' or 'to place'. While it may be concluded that SI-ge4-dam/de3 had nothing to do with the verb si 'to fill' or gi4 'to return', the correct analysis of the expression remains somewhat uncertain. The article proposes that the SI should be read se and understood as a phonetic writing for the regular verb se3.g 'to put', 'to place'. The combination of the verb with the ki-ba may suggest that a more parochial form of keeping products existed side by side with the large centralized granaries and storehouses of the city.La expresión SI-ge4-dam/de3 aparece en algunos contratos de préstamo del período de Ur III, donde se empleaba para determinar el interés de dicho préstamo. Por otra parte, este término se hallaba a veces precedido de ki-ba 'en su/este lugar/suelo', y en algunos casos por ma2 -a 'en la barca'. El verbo regular SI.g está muy relacionado (quizás es incluso sinónimo con el verbo de la clase de la reduplicación ḡar/ḡa2-ḡa2 'poner' o 'colocar'. Mientras que puede concluirse que SI-ge4-dam/de3 no tiene nada que ver con el verbo si 'llenar', ni con gi4 'regresar, devolver', el análisis correcto de la expresión sigue siendo, de algún modo, incierto. En el artículo se propone que SI puede leerse como se , entendiéndolo como una escritura fonética del verbo regular se3.g 'poner', 'colocar'. La combinación del verbo con ki-ba podría indicar que, junto a los grandes graneros y almacenes centrales de la ciudad, había un modo distinto y más modesto de conservar los productos.

  9. Observation of spin-selective tunneling in SiGe nanocrystals.

    Science.gov (United States)

    Katsaros, G; Golovach, V N; Spathis, P; Ares, N; Stoffel, M; Fournel, F; Schmidt, O G; Glazman, L I; De Franceschi, S

    2011-12-09

    Spin-selective tunneling of holes in SiGe nanocrystals contacted by normal-metal leads is reported. The spin selectivity arises from an interplay of the orbital effect of the magnetic field with the strong spin-orbit interaction present in the valence band of the semiconductor. We demonstrate both experimentally and theoretically that spin-selective tunneling in semiconductor nanostructures can be achieved without the use of ferromagnetic contacts. The reported effect, which relies on mixing the light and heavy holes, should be observable in a broad class of quantum-dot systems formed in semiconductors with a degenerate valence band.

  10. Heavy Ion Microbeam- and Broadbeam-Induced Current Transients in SiGe HBTs

    Science.gov (United States)

    Pellish, Jonathan A.; Reed, R. A.; McMorrow, D.; Vizkelethy, G.; Ferlet-Cavrois, V.; Baggio, J.; Duhamel, O.; Moen, K. A.; Phillips, S. D.; Diestelhorst, R. M.; hide

    2009-01-01

    IBM 5AM SiGe HBT is device-under-test. High-speed measurement setup. Low-impedance current transient measurements. SNL, JYFL, GANIL. Microbeam to broadbeam position inference. Improvement to state-of-the-art. Microbeam (SNL) transients reveal position dependent heavy ion response, Unique response for different device regions Unique response for different bias schemes. Similarities to TPA pulsed-laser data. Broadbeam transients (JYFL and GANIL) provide realistic heavy ion response. Feedback using microbeam data. Overcome issues of LET and ion range with microbeam. **Angled Ar-40 data in full paper. Data sets yield first-order results, suitable for TCAD calibration feedback.

  11. Technology computer aided design for Si, SiGe and GaAs integrated circuits

    CERN Document Server

    Armstrong, GA

    2007-01-01

    The first book to deal with a broad spectrum of process and device design, and modelling issues related to semiconductor devices, bridging the gap between device modelling and process design using TCAD. Examples for types of Si-, SiGe-, GaAs- and InP-based heterostructure MOS and bipolar transistors are compared with experimental data from state-of-the-art devices. With various aspects of silicon heterostructures, this book presents a comprehensive perspective of emerging fields and covers topics ranging from materials to fabrication, devices, modelling and applications. Aimed at research-and-

  12. Results of RIKEN superconducting electron cyclotron resonance ion source with 28 GHz.

    Science.gov (United States)

    Higurashi, Y; Ohnishi, J; Nakagawa, T; Haba, H; Tamura, M; Aihara, T; Fujimaki, M; Komiyama, M; Uchiyama, A; Kamigaito, O

    2012-02-01

    We measured the beam intensity of highly charged heavy ions and x-ray heat load for RIKEN superconducting electron cyclotron resonance ion source with 28 GHz microwaves under the various conditions. The beam intensity of Xe(20+) became maximum at B(min) ∼ 0.65 T, which was ∼65% of the magnetic field strength of electron cyclotron resonance (B(ECR)) for 28 GHz microwaves. We observed that the heat load of x-ray increased with decreasing gas pressure and field gradient at resonance zone. It seems that the beam intensity of highly charged heavy ions with 28 GHz is higher than that with 18 GHz at same RF power.

  13. Design of a 300 GHZ broadband coupler and RF-structure

    International Nuclear Information System (INIS)

    Krawczyk, F.L.; Carlsten, B.E.; Earley, L.M.; Sigler, F.E.; Potter, J.M.; Schulze, M.E.

    2004-01-01

    Recent LANL activities in millimeter wave structures focus on 95 and 300 GHz structures. They aim at power generation from low power (100W-2kW) with a round electron beam (120kV, 0.1-1.0 A) to high power (2-100 kW) with a sheet beam structure (120 kV, 20 A). Applications cover basic research, radar and secure communications and remote sensing of biological and chemical agents. In this presentation the design of a 300 GHz RF-structure with a broadband (> 6% bandwidth) power coupler is presented. The choice of two input/output waveguides, a special coupling region and the structure parameters are presented. As a benchmark also a scaled up version at 10 GHz was designed and measured. These results will also be presented. We are investigating planar micro-fabricated traveling-wave tube amplifiers as sources for the generation of millimeter waves from 95 to 300 GHz. While for low energy applications narrow structures with pencil beams are proposed, for high energy operation flat, thin sheet beams are required. For the latter vane-loaded rectangular waveguides that operate in a slow-wave mode matched to the velocity of the electron beam are especially well suited. The 300 GHz effort initially is limited to narrow structures for pencil beams. The main emphasis for this work are the study of fabrication issues and the understanding of features that allow a broadband operation (5-10% bandwidth).

  14. Commissioning of the superconducting ECR ion source VENUS at 18 GHz

    International Nuclear Information System (INIS)

    Leitner, Daniela; Abbott, Steven R.; Dwinell, Roger D.; Leitner, Matthaeus; Taylor, Clyde E.; Lyneis, Claude M.

    2004-01-01

    During the last year, the VENUS ECR ion source was commissioned at 18 GHz and preparations for 28 GHz operation are now underway. During the commissioning phase with 18 GHz, tests with various gases and metals have been performed with up to 2000 W RF power. The ion source performance is very promising [1,2]. VENUS (Versatile ECR ion source for Nuclear Science) is a next generation superconducting ECR ion source, designed to produce high current, high charge state ions for the 88-Inch Cyclotron at the Lawrence Berkeley National Laboratory. VENUS also serves as the prototype ion source for the RIA (Rare Isotope Accelerator) front end. The goal of the VENUS ECR ion source project as the RIA R and D injector is the production of 240e(micro)A of U 30+ , a high current medium charge state beam. On the other hand, as an injector ion source for the 88-Inch Cyclotron the design objective is the production of 5e(micro)A of U 48+ , a low current, very high charge state beam. To meet these ambitious goals, VENUS has been designed for optimum operation at 28 GHz. This frequency choice has several design consequences. To achieve the required magnetic confinement, superconducting magnets have to be used. The size of the superconducting magnet structure implies a relatively large plasma volume. Consequently, high power microwave coupling becomes necessary to achieve sufficient plasma heating power densities. The 28 GHz power supply has been delivered in April 2004

  15. Visible and infrared emission from Si/Ge nanowires synthesized by metal-assisted wet etching.

    Science.gov (United States)

    Irrera, Alessia; Artoni, Pietro; Fioravanti, Valeria; Franzò, Giorgia; Fazio, Barbara; Musumeci, Paolo; Boninelli, Simona; Impellizzeri, Giuliana; Terrasi, Antonio; Priolo, Francesco; Iacona, Fabio

    2014-02-12

    Multi-quantum well Si/Ge nanowires (NWs) were realized by combining molecular beam epitaxy deposition and metal-assisted wet etching, which is a low-cost technique for the synthesis of extremely dense (about 1011 cm-2) arrays of NWs with a high and controllable aspect ratio. In particular, we prepared ultrathin Si/Ge NWs having a mean diameter of about 8 nm and lengths spanning from 1.0 to 2.7 μm. NW diameter is compatible with the occurrence of quantum confinement effects and, accordingly, we observed light emission assignable to the presence of Si and Ge nanostructures. We performed a detailed study of the photoluminescence properties of the NWs, with particular attention to the excitation and de-excitation properties as a function of the temperature and of the excitation photon flux, evaluating the excitation cross section and investigating the presence of non-radiative phenomena. PACS: 61.46.Km; 78.55.-m; 78.67.Lt.

  16. Ordered Arrays of SiGe Islands from Low-Energy PECVD

    Directory of Open Access Journals (Sweden)

    Chrastina D

    2010-01-01

    Full Text Available Abstract SiGe islands have been proposed for applications in the fields of microelectronics, optoelectronics and thermoelectrics. Although most of the works in literature are based on MBE, one of the possible advantages of low-energy plasma-enhanced chemical vapor deposition (LEPECVD is a wider range of deposition rates, which in turn results in the possibility of growing islands with a high Ge concentration. We will show that LEPECVD can be effectively used for the controlled growth of ordered arrays of SiGe islands. In order to control the nucleation of the islands, patterned Si (001 substrates were obtained by e-beam lithography (EBL and dry etching. We realized periodic circular pits with diameters ranging from 80 to 300 nm and depths from 65 to 75 nm. Subsequently, thin films (0.8–3.2 nm of pure Ge were deposited by LEPECVD, resulting in regular and uniform arrays of Ge-rich islands. LEPECVD allowed the use of a wide range of growth rates (0.01–0.1 nm s−1 and substrates temperatures (600–750°C, so that the Ge content of the islands could be varied. Island morphology was characterized by AFM, while μ-Raman was used to analyze the Ge content inside the islands and the composition differences between islands on patterned and unpatterned areas of the substrate.

  17. Development of frequency step tunable 1 MW gyrotron at 131 to 146.5 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Samartsev, A.; Gantenbein, G.; Dammertz, G.; Illy, S.; Kern, S.; Leonhardt, W.; Schlaich, A.; Schmid, M.; Thumm, M., E-mail: andrey.samartsev@kit.edu [Karlsruhe Institute of Technology, Association EURATOM-KIT, Karlsruhe (Germany)

    2011-07-01

    Effective control of power absorption in tokamaks and stellarators could be achieved by the frequency tuning of ECH and CD power delivered by high-power gyrotrons. In this report some results of the development of a frequency tunable gyrotron with fused-silica Brewster window are presented. Excitation of several modes at 1 MW power level in the range of frequencies from 131 to 146.5 GHz is achieved. (author)

  18. A compact high-gradient 25 MeV 17 GHz RF linac for free-electron laser research

    International Nuclear Information System (INIS)

    Danly, B.G.; Chen, S.C.; Kreischer, K.E.

    1995-01-01

    A new compact high-gradient (60 MeV/m) high-frequency (17.136 GHz) RF linac is presently under construction by Haimson Research Corp. (HRC) for installation at the MIT Plasma Fusion Center in the High-Gradient Accelerator and High Power Microwave Laboratory. This accelerator will utilize an existing traveling-wave relativistic klystron (TWRK) which is now operation at MIT with 25 MW power, 67 dB gain, and 52% efficiency at 17.136 GHz

  19. New technologies of information treatment in the ERP of the Almaraz and Trillo nuclear power plants; Nuevas tecnologias de tratamiento de la informacion en el ERP de las centrales nucleares de Almaraz y Trillo

    Energy Technology Data Exchange (ETDEWEB)

    Martin Lopez-Suevos, C.; Gonzalez Crego, E.

    2013-03-01

    The Almaraz and Trillo Nuclear Power Plants are equipped with an Integrated Operation Management System (SIGE), which covers practically all of their transactional and management needs in all areas, with the exception of some specific engineering and simulation tools. In recent years, applications based on new computer technologies have been developed and integrated into the SIGE, including a Maintenance Dashboard, an Admissions Office ant the use of bar code readers, all of which are described in this article. (Author)

  20. The Relationship between Nanocluster Precipitation and Thermal Conductivity in Si/Ge Amorphous Multilayer Films: Effects of Cu Addition

    Directory of Open Access Journals (Sweden)

    Ahmad Ehsan Mohd Tamidi

    2016-01-01

    Full Text Available We have used a molecular dynamics technique to simulate the relationship between nanocluster precipitation and thermal conductivity in Si/Ge amorphous multilayer films, with and without Cu addition. In the study, the Green-Kubo equation was used to calculate thermal conductivity in these materials. Five specimens were prepared: Si/Ge layers, Si/(Ge + Cu layers, (Si + Cu/(Ge + Cu layers, Si/Cu/Ge/Cu layers, and Si/Cu/Ge layers. The number of precipitated nanoclusters in these specimens, which is defined as the number of four-coordinate atoms, was counted along the lateral direction of the specimens. The observed results of precipitate formation were considered in relation to the thermal conductivity results. Enhancement of precipitation of nanoclusters by Cu addition, that is, densification of four-coordinate atoms, can prevent the increment of thermal conductivity. Cu dopant increases the thermal conductivity of these materials. Combining these two points, we concluded that Si/Cu/Ge is the best structure to improve the conversion efficiency of the Si/Ge amorphous multilayer films.

  1. A 31 GHz Survey of Low-Frequency Selected Radio Sources

    Science.gov (United States)

    Mason, B. S.; Weintraub, L.; Sievers, J.; Bond, J. R.; Myers, S. T.; Pearson, T. J.; Readhead, A. C. S.; Shepherd, M. C.

    2009-10-01

    The 100 m Robert C. Byrd Green Bank Telescope and the 40 m Owens Valley Radio Observatory telescope have been used to conduct a 31 GHz survey of 3165 known extragalactic radio sources over 143 deg2 of the sky. Target sources were selected from the NRAO VLA Sky Survey in fields observed by the Cosmic Background Imager (CBI); most are extragalactic active galactic nuclei (AGNs) with 1.4 GHz flux densities of 3-10 mJy. The resulting 31 GHz catalogs are presented in full online. Using a maximum-likelihood analysis to obtain an unbiased estimate of the distribution of the 1.4-31 GHz spectral indices of these sources, we find a mean 31-1.4 GHz flux ratio of 0.110 ± 0.003 corresponding to a spectral index of α = -0.71 ± 0.01 (S ν vprop να) 9.0% ± 0.8% of sources have α > - 0.5 and 1.2% ± 0.2% have α > 0. By combining this spectral-index distribution with 1.4 GHz source counts, we predict 31 GHz source counts in the range 1 mJy S 31) = (16.7 ± 1.7) deg-2(S 31/1 mJy)-0.80±0.07. We also assess the contribution of mJy-level (S 1.4 GHz < 3.4 mJy) radio sources to the 31 GHz cosmic microwave background power spectrum, finding a mean power of ell(ell + 1)C src ell/(2π) = 44 ± 14 μK2 and a 95% upper limit of 80 μK2 at ell = 2500. Including an estimated contribution of 12 μK2 from the population of sources responsible for the turn-up in counts below S 1.4 GHz = 1 mJy, this amounts to 21% ± 7% of what is needed to explain the CBI high-ell excess signal, 275 ± 63 μK2. These results are consistent with other measurements of the 31 GHz point-source foreground.

  2. 100 GHz Externally Modulated Laser for Optical Interconnects Applications

    DEFF Research Database (Denmark)

    Ozolins, Oskars; Pang, Xiaodan; Iglesias Olmedo, Miguel

    2017-01-01

    We report on a 116 Gb/s on-off keying (OOK), four pulse amplitude modulation (PAM) and 105-Gb/s 8-PAM optical transmitter using an InP-based integrated and packaged externally modulated laser for high-speed optical interconnects with up to 30 dB static extinction ratio and over 100-GHz 3-d......B bandwidth with 2 dB ripple. In addition, we study the tradeoff between power penalty and equalizer length to foresee transmission distances with standard single mode fiber....

  3. The 30/20 GHz experimental communications satellite system

    Science.gov (United States)

    Sivo, J. N.

    NASA is continuing to pursue an agressive satellite communications technology development program focused on the 30/20 GHz frequency band. A review of the program progress to date is presented. Included is a discussion of the technology program status as well as a description of the experimental system concept under study. Expected system performance characteristics together with spacecraft and payload configuration details including weight and power budget is presented. Overall program schedules of both the technology development and the flight system development are included.

  4. A 30 GHz 5-TeV Linear Collider

    International Nuclear Information System (INIS)

    Wilson, Perry B

    2003-01-01

    We present parameters for a linear collider with a 3 to 5 TeV center-of-mass energy that utilizes conventional rf technology operating at a frequency around 30 GHz. We discuss the scaling laws and assumed limitations that lead to the parameters described and we compare the merits and liabilities of different technological options including rf power source, accelerator structure, and final focus system design. Finally, we outline the components of the collider while specifying the required alignment and construction tolerances

  5. Transmission Line for 258 GHz Gyrotron DNP Spectrometry

    Science.gov (United States)

    Bogdashov, Alexandr A.; Belousov, Vladimir I.; Chirkov, Alexey V.; Denisov, Gregory G.; Korchagin, Vyacheslav V.; Kornishin, Sergey Yu.; Tai, Evgeny M.

    2011-06-01

    We describe the design and test results of the transmission line for liquid-state (LS) and solid-state (SS) DNP spectrometers with the second-harmonic 258.6 GHz gyrotron at the Institute of the Biophysical Chemistry Center of Goethe University (Frankfurt). The 13-meter line includes a mode converter, HE11 waveguides, 4 mitre bends, a variable polarizer-attenuator, directional couplers, a water-flow calorimeter and a mechanical switch. A microwave power of about 15 W was obtained in the pure HE11 mode at the spectrometer inputs.

  6. Antenne Design for 24 GHz and 60 GHz Emerging Microwave Applications

    NARCIS (Netherlands)

    Jansen, F.; Dolmans, W.M.C.

    2006-01-01

    In this project integrated antennas on a LAMP3 substrate for automotive radar systems at 24 GHz and wireless networks at 60 GHz have been designed. The most severe requirements on the antennas were the large bandwidth, which can not be met with conventional patch antennas. A tapered slot antenna and

  7. Contactless Investigations of Yeast Cell Cultivation in the 7 GHz and 240 GHz Ranges

    International Nuclear Information System (INIS)

    Wessel, J; Schmalz, K; Meliani, C; Gastrock, G; Cahill, B P

    2013-01-01

    Using a microfluidic system based on PTFE tubes, experimental results of contactless and label-free characterization techniques of yeast cell cultivation are presented. The PTFE tube has an inner diameter of 0.5 mm resulting in a sample volume of 2 μ1 for 1 cm sample length. Two approaches (at frequencies around 7 GHz and 240 GHz) are presented and compared in terms of sensitivity and applicability. These frequency bands are particularly interesting to gain information on the permittivity of yeast cells in Glucose solution. Measurements from 240 GHz to 300 GHz were conducted with a continuous wave spectrometer from Toptica. At 7 GHz band, measurements have been performed using a rat-race based characterizing system realized on a printed circuit board. The conducted experiments demonstrate that by selecting the phase as characterization parameter, the presented contactless and label-free techniques are suitable for cell cultivation monitoring in a PTFE pipe based microfluidic system.

  8. Heterodyne detection at 300 GHz using neon indicator lamp glow discharge detector.

    Science.gov (United States)

    Aharon Akram, Avihai; Rozban, Daniel; Kopeika, Natan S; Abramovich, Amir

    2013-06-10

    A miniature neon indicator lamp, also known as a glow discharge detector (GDD), costing about 50 cents, was found to be an excellent room temperature terahertz radiation detector. Proof-of-concept 300 GHz heterodyne detection using GDD is demonstrated in this paper. Furthermore, a comparison to direct detection was carried out as well. Previous results with the GDD at 10 GHz showed 40 times better sensitivity using heterodyne detection compared to direct detection. Preliminary results at 300 GHz showed better sensitivity by a factor of 20 with only 56 μW local-oscillator power using heterodyne compared to direct detection. The higher the local-oscillator power (P(lo)), the better the sensitivity of the detector. Further improvement can be achieved by employing better quasi-optical design.

  9. Effects of Variable Spot Size on Human Exposure to 95 GHz Millimeter Wave Energy

    Science.gov (United States)

    2017-05-11

    Laboratory. Ross, J. A., Allen, S. J., Beason, C. W., & Johnson, L. R. (2008). Power density measurement of 94-GHz radiofrequency radiation using carbon...effectiveness) at the smallest spot size. 15. SUBJECT TERMS Avoidance, behavior, millimeter waves, nonlethal weapons, radiofrequency 16...System power density measurements (mean ± standard deviation) for the three different power density settings (low, middle, high) used in Experiment 1B

  10. Boron diffusion in strained and strain-relaxed SiGe

    International Nuclear Information System (INIS)

    Wang, C.C.; Sheu, Y.M.; Liu, Sally; Duffy, R.; Heringa, A.; Cowern, N.E.B.; Griffin, P.B.

    2005-01-01

    SiGe has been utilized for aggressive CMOS technologies development recently and there are many references [M. Shima, T. Ueno, T. Kumise, H. Shido, Y. Sakuma, S. Nakamura, Symposium on VLSI Technology Technical Digest, 2002, pp. 94-95; T. Ghani, M. Armstrong, C. Auth, M. Bost, P. Charvat, G. Glass, T. Hoffmann, K. Johnson, C. Kenyon, J. Klaus, B. McIntyre, K. Mistry, A. Murthy, J. Sandford, M. Silberstein, S. Sivakumar, P. Smith, K. Zawadzki, S. Thompson, M. Bohr, International Electron Devices Meeting Technical Digest, December 2003, pp. 978-980; P. Bai, C. Auth, S. Balakrishnan, M. Bost, R. Brain, V. Chikarmane, R. Heussner, M. Hussein, J. Hwang, D. Ingerly, R. James, J. Jeong, C. Kenyon, E. Lee, S. Lee, N. Lindert, M. Liu, Z. Ma, T. Marieb, A. Murthy, R. Nagisetty, S. Natarajan, J. Neirynck, A. Ott, C. Parker, J. Sebastian, R. Shaheed, S. Sivakumar, J. Steigerwald, S. Tyagi, C. Weber, B. Woolery, A. Yeoh, K. Zhang, M. Bohr, International Electron Devices Meeting Technical Digest, December 2004, pp. 657-660] presenting the advantages brought by it. A better understanding regarding the boron diffusion behavior within and in the vicinity of SiGe is necessary to optimize the extension and the source/drain in pMOSFET. In order to achieve the goal, both effects from mechanical strain and Ge doping on boron diffusion have been investigated. However, only a few publications discuss the impacts of both. Furthermore, most researches investigate these two effects under the conditions of low boron concentration [P. Kuo, J.L. Hoyt, J.F. Gibbons, J.E. Turner, D. Lefforge, Appl. Phys. Lett. 66 (January (5)) (1995) 580-582; N.R. Zangenberg, J. Fage-Pedersen, J. Lundsgaard Hansen, A. Nylandsted Larsen, J. Appl. Phys. 94 (September (6)) (2003) 3883-3890] and high thermal budget anneal [P. Kuo, J.L. Hoyt, J.F. Gibbons, J.E. Turner, D. Lefforge, Appl. Phys. Lett. 66 (January (5)) (1995) 580-582; N.R. Zangenberg, J. Fage-Pedersen, J. Lundsgaard Hansen, A. Nylandsted Larsen, J. Appl

  11. Degradation of Au–Ti contacts of SiGe HBTs during electromagnetic field stress

    International Nuclear Information System (INIS)

    Alaeddine, A; Genevois, C; Cuvilly, F; Daoud, K; Kadi, M

    2011-01-01

    This paper addresses electromagnetic field stress effects on SiGe heterojunction bipolar transistors (HBTs)' reliability issues, focusing on the relationship between the stress-induced current and device structure degradations. The origin of leakage currents and electrical parameter shifts in failed transistors has been studied by complementary failure analysis techniques. Characterization of the structure before and after ageing was performed by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). For the stressed samples, interface deformations of the titanium (Ti) thin film around all gold (Au) contacts have been clearly detected. These degradations include localized interface reaction between Au and Ti layers as well as their lateral atomic migration causing a significant reduction of Ti thickness. EDS analysis of the disordered region which is near the Si 3 N 4 interface has shown significant signals from Au. These observations could be attributed to the coupling between high current densities induced by stress and thermal effects due to local heating effects

  12. Examination Of Si-Ge Heterostructure Nanowire Growth Using Monte Carlo Simulation

    International Nuclear Information System (INIS)

    Nastovjak, A. G.; Neizvestny, I. G.; Shwartz, N. L.

    2011-01-01

    The process of Si-Ge heterostructures formation in nanowires (NWs) grown by vapor-liquid-solid mechanism was investigated using Monte Carlo simulation. Dependences of catalyst drop composition on temperature, flux intensity and nanowire diameter were obtained. Periodical oscillations of drop composition near mean value were observed. Oscillation results from layer-by-layer growth at the drop-whisker interface and necessity of supersaturation onset to start new layer formation. It was demonstrated that it is impossible to grow atomically abrupt axial heterojunctions via classical vapor-liquid-solid mechanism due to gradual change of catalyst drop composition when switching the fluxes. This phenomenon is the main reason of heterojunction blurriness. Junction abruptness was found to be dependent on nanowhisker diameter: in adsorption-induced growth mode abruptness of heterojunction decreases with diameter and in diffusion-induced mode it increases.

  13. Anomalous dose rate effects in gamma irradiated SiGe heterojunction bipolar transistors

    International Nuclear Information System (INIS)

    Banerjee, G.; Niu, G.; Cressler, J.D.; Clark, S.D.; Palmer, M.J.; Ahlgren, D.C.

    1999-01-01

    Low dose rate (LDR) cobalt-60 (0.1 rad(Si)/s) gamma irradiated Silicon Germanium (SiGe) Heterojunction Bipolar Transistors (HBTs) were studied. Comparisons were made with devices irradiated with 300 rad(Si)/s gamma radiation to verify if LDR radiation is a serious radiation hardness assurance (RHA) issue. Almost no LDR degradation was observed in this technology up to 50 krad(Si). The assumption of the presence of two competing mechanisms is justified by experimental results. At low total dose (le20 krad), an anomalous base current decrease was observed which is attributed to self-annealing of deep-level traps to shallower levels. An increase in base current at larger total doses is attributed to radiation induced generation-recombination (G/R) center generation. Experiments on gate-assisted lateral PNP transistors and 2D numerical simulations using MEDICI were used to confirm these assertions

  14. Micromachined single-level nonplanar polycrystalline SiGe thermal microemitters for infrared dynamic scene projection

    Science.gov (United States)

    Malyutenko, V. K.; Malyutenko, O. Yu.; Leonov, V.; Van Hoof, C.

    2009-05-01

    The technology for self-supported membraneless polycrystalline SiGe thermal microemitters, their design, and performance are presented. The 128-element arrays with a fill factor of 88% and a 2.5-μm-thick resonant cavity have been grown by low-pressure chemical vapor deposition and fabricated using surface micromachining technology. The 200-nm-thick 60×60 μm2 emitting pixels enforced with a U-shape profile pattern demonstrate a thermal time constant of 2-7 ms and an apparent temperature of 700 K in the 3-5 and 8-12 μm atmospheric transparency windows. The application of the devices to the infrared dynamic scene simulation and their benefit over conventional planar membrane-supported emitters are discussed.

  15. Surface and interfacial structural characterization of MBE grown Si/Ge multilayers

    International Nuclear Information System (INIS)

    Saha, Biswajit; Sharma, Manjula; Sarma, Abhisakh; Rath, Ashutosh; Satyam, P.V.; Chakraborty, Purushottam; Sanyal, Milan K.

    2009-01-01

    Si/Ge multilayer structures have been grown by solid source molecular beam epitaxy (MBE) on Si (1 1 1) and (1 0 0) substrates and were characterized by high-resolution X-ray diffraction (XRD), atomic force microscopy (AFM), high-depth-resolution secondary ion mass spectroscopy (SIMS) and cross-section high-resolution transmission electron microscopy (HRTEM). A reasonably good agreement has been obtained for layer thickness, interfacial structure and diffusion between SIMS and HRTEM measurements. Epitaxial growth and crystalline nature of the individual layer have been probed using cross-sectional HRTEM and XRD measurements. Surface and interface morphological studies by AFM and HRTEM show island-like growth of both Si and Ge nanostructures.

  16. Self-assembly of InAs and Si/Ge quantum dots on structured surfaces

    International Nuclear Information System (INIS)

    Patella, F; Sgarlata, A; Arciprete, F; Nufris, S; Szkutnik, P D; Placidi, E; Fanfoni, M; Motta, N; Balzarotti, A

    2004-01-01

    We discuss the self-aggregation process of InAs and Si-Ge quantum dots (QDs) on natural and patterned GaAs(001) and Si(001) and Si(111) surfaces, with reference to our recent studies with scanning tunnelling and atomic force microscopy and current experimental and theoretical works. Various methods for obtaining naturally structured surfaces are briefly surveyed, as the patterning formed by the surface instability and by the strain in mismatched heteroepitaxy, and the latest methods of pre-patterning and growth at selected sites are discussed. Basic topics are also addressed that determine the final morphology of QDs, such as the wetting layer formation, the elastic strain field and the two-dimensional to three-dimensional phase transition

  17. Impacts of doping on epitaxial germanium thin film quality and Si-Ge interdiffusion

    KAUST Repository

    Zhou, Guangnan

    2018-04-03

    Ge-on-Si structures with three different dopants (P, As and B) and those without intentional doping were grown, annealed and characterized by several different material characterization methods. All samples have a smooth surface (roughness < 1.5 nm), and the Ge films are almost entirely relaxed. B doped Ge films have threading dislocations above 1 × 10 cm, while P and As doping can reduce the threading dislocation density to be less than 10 cm without annealing. The interdiffusion of Si and Ge of different films have been investigated experimentally and theoretically. A quantitative model of Si-Ge interdiffusion under extrinsic conditions across the full x range was established including the dislocationmediated diffusion. The Kirkendall effect has been observed. The results are of technical significance for the structure, doping, and process design of Ge-on-Si based devices, especially for photonic applications.

  18. Reliability of high mobility SiGe channel MOSFETs for future CMOS applications

    CERN Document Server

    Franco, Jacopo; Groeseneken, Guido

    2014-01-01

    Due to the ever increasing electric fields in scaled CMOS devices, reliability is becoming a showstopper for further scaled technology nodes. Although several groups have already demonstrated functional Si channel devices with aggressively scaled Equivalent Oxide Thickness (EOT) down to 5Å, a 10 year reliable device operation cannot be guaranteed anymore due to severe Negative Bias Temperature Instability. This book focuses on the reliability of the novel (Si)Ge channel quantum well pMOSFET technology. This technology is being considered for possible implementation in next CMOS technology nodes, thanks to its benefit in terms of carrier mobility and device threshold voltage tuning. We observe that it also opens a degree of freedom for device reliability optimization. By properly tuning the device gate stack, sufficiently reliable ultra-thin EOT devices with a 10 years lifetime at operating conditions are demonstrated. The extensive experimental datasets collected on a variety of processed 300mm wafers and pr...

  19. Influence of alloy disorder scattering on the hole mobility of SiGe nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Blanque, Celso; Ruiz, Francisco G., E-mail: franruiz@ugr.es; Godoy, Andres, E-mail: agodoy@ugr.es; Marin, Enrique G.; Donetti, Luca; Gámiz, Francisco [Dpto. de Electrónica y Tecnología de Computadores, Facultad de Ciencias, Universidad de Granada, Av. Fuentenueva S/N, 18071 Granada (Spain)

    2014-12-28

    In this work, we analyze the influence of the alloy disorder (AD) scattering on the low-field hole mobility of Si{sub 1-x}Ge{sub x} nanowires (NWs). To do it, the electrostatic description is achieved through a self-consistent solution of the Poisson equation and the six-band k⋅p method in the cross section of the NW. The momentum relaxation time approximation is used to calculate the hole mobility, including alloy disorder and phonon scattering mechanisms, and the use of approximations to calculate the overlap integrals for the scattering matrix elements is discussed. We study the influence of the alloy disorder scattering on the total mobility compared to the phonon contribution, for different values of the AD scattering parameter proposed in the literature, and analyze the performance of SiGe NWs as a function of the Ge molar fraction for both low and high inversion charge densities.

  20. Impacts of doping on epitaxial germanium thin film quality and Si-Ge interdiffusion

    KAUST Repository

    Zhou, Guangnan; Lee, Kwang Hong; Anjum, Dalaver H.; Zhang, Qiang; Zhang, Xixiang; Tan, Chuan Seng; Xia, Guangrui

    2018-01-01

    Ge-on-Si structures with three different dopants (P, As and B) and those without intentional doping were grown, annealed and characterized by several different material characterization methods. All samples have a smooth surface (roughness < 1.5 nm), and the Ge films are almost entirely relaxed. B doped Ge films have threading dislocations above 1 × 10 cm, while P and As doping can reduce the threading dislocation density to be less than 10 cm without annealing. The interdiffusion of Si and Ge of different films have been investigated experimentally and theoretically. A quantitative model of Si-Ge interdiffusion under extrinsic conditions across the full x range was established including the dislocationmediated diffusion. The Kirkendall effect has been observed. The results are of technical significance for the structure, doping, and process design of Ge-on-Si based devices, especially for photonic applications.

  1. Wideband Circularly Polarized Printed Ring Slot Antenna for 5 GHz – 6 GHz

    Science.gov (United States)

    Nasrun Osman, Mohamed; Rahim, Mohamad Helmi A.; Jusoh, Muzammil; Sabapathy, Thennarasan; Rahim, Mohamad Kamal A.; Norlyana Azemi, Saidatul

    2018-03-01

    This paper presents the design of circularly polarized printed slot antenna operating at 5 – 6 GHz. The proposed antenna consists of L-shaped feedline on the top of structure and circular ring slot positioned at the ground plane underneath the substrate as a radiator. A radial and narrow slot in the ground plane provides coupling between the L-shaped feedline and circular ring slot. The circular polarization is realized by implementing the slits perturbation located diagonally to perturb the current flow on the slot structure. The antenna prototype is fabricated on FR4 substrate. The simulated and measured results are compared and analyzed to demonstrate the performance of the antenna. Good measured of simulated results are obtained at the targeted operating frequency. The simulated -10dB reflection coefficient bandwidths and axial ratio are 750 MHz and 165 MHz, respectively. The investigation on the affect of the important parameters towards the reflection coefficient and axial are also presented. The proposed antenna is highly potential to be used for wireless local area network (WLAN) and wireless power transfer (WPT).

  2. Integrated 60GHz RF Beamforming in CMOS

    NARCIS (Netherlands)

    Yu, Yikun; Baltus, P.G.M.; Roermund, van A.H.M.

    2011-01-01

    The 60GHz band is promising for applications such as high-speed short-range wireless personal area network (WPAN), real time video streaming at rates of several Gbps, automotive radar, and mm-Wave imaging, since it provides a large amount of bandwidth that can freely (i.e. without a license) be used

  3. A 24GHz Radar Receiver in CMOS

    NARCIS (Netherlands)

    Kwok, K.C.

    2015-01-01

    This thesis investigates the system design and circuit implementation of a 24GHz-band short-range radar receiver in CMOS technology. The propagation and penetration properties of EM wave offer the possibility of non-contact based remote sensing and through-the-wall imaging of distance stationary or

  4. The Use of a 28 GHz Gyrotron for EBW Startup Experiments on MAST

    Science.gov (United States)

    Caughman, J. B.; Bigelow, T. S.; Diem, S. J.; Peng, Y. K. M.; Rasmussen, D. A.; Shevchenko, V.; Hawes, J.; Lloyd, B.

    2009-11-01

    The use of electron Bernstein waves for non-inductive plasma current startup in MAST has recently been demonstrated [1]. The injection of 100 kW at 28 GHz generated plasma currents of up to 33 kA without the use of solenoid flux, and limited solenoid assist resulted in up to 55 kA of plasma current. A higher power 28 GHz gyrotron, with power levels of up to 300 kW for 0.5 seconds, is currently being commissioned. It is being used to investigate the scaling of startup current with microwave power and power profile as a function of time. Power modulation experiments are also being explored. Gyrotron performance and experimental results will be presented. [4pt] [1] V. Shevchenko, et al., Proceedings of the 15^th Joint Workshop on ECE and ECRH, Yosimite, USA, p. 68 (2009)

  5. Magnetic films for GHz applications (abstract)

    International Nuclear Information System (INIS)

    Korenivski, V.; van Dover, R.B.

    1997-01-01

    Tremendous growth of the communications industry and the increasingly high demand for low-cost light-weight/small-size products drive technology to designs with a high degree of integration. In particular, planar inductors used in integrated circuits with significantly improved inductance per unit area characteristics are needed for further miniaturization of cellular phones operating at 0.95 and 1.9 GHz. Little has been done, however, to use magnetic films to improve the performance and/or reduce size of planar magnetic flux devices. The successful thin-film material would have a high ferromagnetic resonance (FMR) frequency (well above the operating frequency of the device), large permaeability, and low magnetic loss, and very importantly be technologically attractive, i.e., be process compatible with IC technology and have as few preparation steps as possible. Here, we report on fabrication of metallic ferromagnetic films of CoNbZr, CoNbZr/AlN mulitilayered laminates, and exchange-biased structures suitable for GHz applications. Lamination of CoNbZr with thin insulating layers of AlN is shown to significantly improve the microstructure and dc magnetic properties of the films having thicknesses >0.2 μm, as well as to be effective in suppressing eddy current losses at frequencies up to 1 endash 2 GHz. We use exchange biasing to increase the FMR frequency of soft CoNbZr. In-plane unidirectional anisotropy fields of ∼50 Oe are achieved, which result in FMR frequencies >2 GHz. Permeability values of ∼200 with quality factors of ∼10 at 1 GHz are demonstrated. The films are deposited at room temperature and require no postdeposition processing. Application of these films in planar inductors is discussed.copyright 1997 American Institute of Physics

  6. Array of 1- to 2-GHz electrodes for stochastic cooling

    International Nuclear Information System (INIS)

    Voelker, F.; Henderson, T.; Johnson, J.

    1983-03-01

    Described is an array of directional-coupler loop pairs that are to be used as either pickup or kicker electrodes for the frequency range of 1 to 2 GHz. Each coupler pair is a lambda/4 long parallel-plane transmission line that is arranged to be flush with the upper and lower surfaces of a rectangular beam pipe. As pickups, the coupler pairs are used in arrays and are operated at 80 degrees Kelvin for improving the signal-to-noise ratio. The loop output power is added in stripline combiner networks before being fed to a low-noise preamplifier. When the couplers are used as kickers, the combining network serves to split power and distribute it uniformly to each electrode

  7. 47.8 GHz InPHBT quadrature VCO with 22% tuning range

    DEFF Research Database (Denmark)

    Hadziabdic, Dzenan; Johansen, Tom Keinicke; Krozer, Viktor

    2007-01-01

    A 38-47.8 GHz quadrature voltage controlled oscillator (QVCO) in InP HBT technology is presented. The measured output power is - 15 dBm. The simulated phase noise ranges from -84 to -86 dBc/Hz at 1 MHz offset. It is believed that this is the first millimetre-wavc QVCO implemented in InP HBT...

  8. Co-integration of an RF engergy harverster into a 2.4 GHz transceiver

    NARCIS (Netherlands)

    Masuch, J.; Delgado-Restituto, M.; Milosevic, D.; Baltus, P.G.M.

    2013-01-01

    This paper presents an RF energy harvester embedded in a low-power transceiver (TRX) front-end. Both the harvester and the TRX use the same antenna and operate at the same frequency of 2.4 GHz. To decouple the harvester from the TRX, different concepts are proposed regarding the transmitter (TX) and

  9. A self-ordered, body-centered tetragonal superlattice of SiGe nanodot growth by reduced pressure CVD

    Science.gov (United States)

    Yamamoto, Yuji; Zaumseil, Peter; Capellini, Giovanni; Schubert, Markus Andreas; Hesse, Anne; Albani, Marco; Bergamaschini, Roberto; Montalenti, Francesco; Schroeder, Thomas; Tillack, Bernd

    2017-12-01

    Self-ordered three-dimensional body-centered tetragonal (BCT) SiGe nanodot structures are fabricated by depositing SiGe/Si superlattice layer stacks using reduced pressure chemical vapor deposition. For high enough Ge content in the island (>30%) and deposition temperature of the Si spacer layers (T > 700 °C), we observe the formation of an ordered array with islands arranged in staggered position in adjacent layers. The in plane periodicity of the islands can be selected by a suitable choice of the annealing temperature before the Si spacer layer growth and of the SiGe dot volume, while only a weak influence of the Ge concentration is observed. Phase-field simulations are used to clarify the driving force determining the observed BCT ordering, shedding light on the competition between heteroepitaxial strain and surface-energy minimization in the presence of a non-negligible surface roughness.

  10. Evaluation of COTS SiGe, SOI, and Mixed Signal Electronic Parts for Extreme Temperature Use in NASA Missions

    Science.gov (United States)

    Patterson, Richard L.; Hammoud, Ahmad

    2010-01-01

    The NASA Electronic Parts and Packaging (NEPP) Program sponsors a task at the NASA Glenn Research Center titled "Reliability of SiGe, SOI, and Advanced Mixed Signal Devices for Cryogenic Space Missions." In this task COTS parts and flight-like are evaluated by determining their performance under extreme temperatures and thermal cycling. The results from the evaluations are published on the NEPP website and at professional conferences in order to disseminate information to mission planners and system designers. This presentation discusses the task and the 2010 highlights and technical results. Topics include extreme temperature operation of SiGe and SOI devices, all-silicon oscillators, a floating gate voltage reference, a MEMS oscillator, extreme temperature resistors and capacitors, and a high temperature silicon operational amplifier.

  11. Structural, dynamic, and vibrational properties during heat transfer in Si/Ge superlattices: A Car-Parrinello molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Pengfei; Zhang, Yuwen, E-mail: zhangyu@missouri.edu [Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, Missouri 65211 (United States); Yang, Mo [College of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China)

    2013-12-21

    The structural, dynamic, and vibrational properties during heat transfer process in Si/Ge superlattices are studied by analyzing the trajectories generated by the ab initio Car-Parrinello molecular dynamics simulation. The radial distribution functions and mean square displacements are calculated and further discussions are made to explain and probe the structural changes relating to the heat transfer phenomenon. Furthermore, the vibrational density of states of the two layers (Si/Ge) are computed and plotted to analyze the contributions of phonons with different frequencies to the heat conduction. Coherent heat conduction of the low frequency phonons is found and their contributions to facilitate heat transfer are confirmed. The Car-Parrinello molecular dynamics simulation outputs in the work show reasonable thermophysical results of the thermal energy transport process and shed light on the potential applications of treating the heat transfer in the superlattices of semiconductor materials from a quantum mechanical molecular dynamics simulation perspective.

  12. Structural, dynamic, and vibrational properties during heat transfer in Si/Ge superlattices: A Car-Parrinello molecular dynamics study

    International Nuclear Information System (INIS)

    Ji, Pengfei; Zhang, Yuwen; Yang, Mo

    2013-01-01

    The structural, dynamic, and vibrational properties during heat transfer process in Si/Ge superlattices are studied by analyzing the trajectories generated by the ab initio Car-Parrinello molecular dynamics simulation. The radial distribution functions and mean square displacements are calculated and further discussions are made to explain and probe the structural changes relating to the heat transfer phenomenon. Furthermore, the vibrational density of states of the two layers (Si/Ge) are computed and plotted to analyze the contributions of phonons with different frequencies to the heat conduction. Coherent heat conduction of the low frequency phonons is found and their contributions to facilitate heat transfer are confirmed. The Car-Parrinello molecular dynamics simulation outputs in the work show reasonable thermophysical results of the thermal energy transport process and shed light on the potential applications of treating the heat transfer in the superlattices of semiconductor materials from a quantum mechanical molecular dynamics simulation perspective

  13. Structural, dynamic, and vibrational properties during heat transfer in Si/Ge superlattices: A Car-Parrinello molecular dynamics study

    Science.gov (United States)

    Ji, Pengfei; Zhang, Yuwen; Yang, Mo

    2013-12-01

    The structural, dynamic, and vibrational properties during heat transfer process in Si/Ge superlattices are studied by analyzing the trajectories generated by the ab initio Car-Parrinello molecular dynamics simulation. The radial distribution functions and mean square displacements are calculated and further discussions are made to explain and probe the structural changes relating to the heat transfer phenomenon. Furthermore, the vibrational density of states of the two layers (Si/Ge) are computed and plotted to analyze the contributions of phonons with different frequencies to the heat conduction. Coherent heat conduction of the low frequency phonons is found and their contributions to facilitate heat transfer are confirmed. The Car-Parrinello molecular dynamics simulation outputs in the work show reasonable thermophysical results of the thermal energy transport process and shed light on the potential applications of treating the heat transfer in the superlattices of semiconductor materials from a quantum mechanical molecular dynamics simulation perspective.

  14. Nanogrids and Beehive-Like Nanostructures Formed by Plasma Etching the Self-Organized SiGe Islands

    Science.gov (United States)

    Chang, Yuan-Ming; Jian, Sheng-Rui; Juang, Jenh-Yih

    2010-09-01

    A lithography-free method for fabricating the nanogrids and quasi-beehive nanostructures on Si substrates is developed. It combines sequential treatments of thermal annealing with reactive ion etching (RIE) on SiGe thin films grown on (100)-Si substrates. The SiGe thin films deposited by ultrahigh vacuum chemical vapor deposition form self-assembled nanoislands via the strain-induced surface roughening (Asaro-Tiller-Grinfeld instability) during thermal annealing, which, in turn, serve as patterned sacrifice regions for subsequent RIE process carried out for fabricating nanogrids and beehive-like nanostructures on Si substrates. The scanning electron microscopy and atomic force microscopy observations confirmed that the resultant pattern of the obtained structures can be manipulated by tuning the treatment conditions, suggesting an interesting alternative route of producing self-organized nanostructures.

  15. Effect of strain, substrate surface and growth rate on B-doping in selectively grown SiGe layers

    International Nuclear Information System (INIS)

    Ghandi, R.; Kolahdouz, M.; Hallstedt, J.; Wise, R.; Wejtmans, Hans; Radamson, H.H.

    2008-01-01

    In this work, the role of strain and growth rate on boron incorporation in selective epitaxial growth (SEG) of B-doped Si 1-x Ge x (x = 0.15-0.25) layers in recessed or unprocessed (elevated) openings for source/drain applications in CMOS has been studied. A focus has been made on the strain distribution and B incorporation in SEG of SiGe layers

  16. Effect of strain, substrate surface and growth rate on B-doping in selectively grown SiGe layers

    Energy Technology Data Exchange (ETDEWEB)

    Ghandi, R. [School of Information and Communication Technology, KTH (Royal Institute of Technology), Isafjordsg. 22-26, Electrum 229, 16640 Kista (Sweden)], E-mail: ghandi@kth.se; Kolahdouz, M.; Hallstedt, J. [School of Information and Communication Technology, KTH (Royal Institute of Technology), Isafjordsg. 22-26, Electrum 229, 16640 Kista (Sweden); Wise, R.; Wejtmans, Hans [Texas Instrument, 13121 TI Boulevard, Dallas, Tx 75243 (United States); Radamson, H.H. [School of Information and Communication Technology, KTH (Royal Institute of Technology), Isafjordsg. 22-26, Electrum 229, 16640 Kista (Sweden)

    2008-11-03

    In this work, the role of strain and growth rate on boron incorporation in selective epitaxial growth (SEG) of B-doped Si{sub 1-x}Ge{sub x} (x = 0.15-0.25) layers in recessed or unprocessed (elevated) openings for source/drain applications in CMOS has been studied. A focus has been made on the strain distribution and B incorporation in SEG of SiGe layers.

  17. The influence of a Si cap on self-organized SiGe islands and the underlying wetting layer

    International Nuclear Information System (INIS)

    Brehm, M.; Grydlik, M.; Groiss, H.; Hackl, F.; Schaeffler, F.; Fromherz, T.; Bauer, G.

    2011-01-01

    For the prototypical SiGe/Si(001) Stranski-Krastanow (SK) growth system, the influence of intermixing caused by the deposition of a Si cap layer at temperatures T cap between 300 deg. C and 700 deg. C is studied both for the SiGe wetting layer (WL) and the SiGe islands. Systematic growth experiments were carried out with an ultrahigh resolution of down to 0.005 monolayers (ML) of deposited Ge. The properties of the samples were investigated via photoluminescence (PL) spectroscopy, atomic force microscopy (AFM), and transmission electron microscopy. We studied in detail the influence of T cap in the three main coverage regions of SiGe SK growth, which are (i) the WL build-up regime, (ii) the island nucleation regime, where most of the Ge is supplied via material transfer from the WL, and (iii) the saturation regime, where the WL thickness remains initially stable. At T cap = 300 deg. C, we found that both the WL and the island are essentially preserved in composition and shape, whereas at 500 deg. C the WL becomes heavily alloyed during capping, and at 700 deg. C the islands also become alloyed. At T cap = 500 deg. C we found enhanced WL intermixing in the presence of dome-shaped islands, whereas at T cap 700 deg. C the WL properties become dominated by the dissolution of pyramid-shaped islands upon capping. At Ge coverages above ≅6 ML, we found an unexpected thickening of the WL, almost independently of T cap . This finding suggests that the density and the volume of the dome-shaped islands have an upper limit, beyond which excess Ge from the external source again becomes incorporated into the WL. Finally, we compared PL spectra with AFM-based evaluations of the integral island volumes in order to determine in a straightforward manner the average composition of the SiGe islands.

  18. On the interplay between phonon-boundary scattering and phonon-point-defect scattering in SiGe thin films

    Science.gov (United States)

    Iskandar, A.; Abou-Khalil, A.; Kazan, M.; Kassem, W.; Volz, S.

    2015-03-01

    This paper provides theoretical understanding of the interplay between the scattering of phonons by the boundaries and point-defects in SiGe thin films. It also provides a tool for the design of SiGe-based high-efficiency thermoelectric devices. The contributions of the alloy composition, grain size, and film thickness to the phonon scattering rate are described by a model for the thermal conductivity based on the single-mode relaxation time approximation. The exact Boltzmann equation including spatial dependence of phonon distribution function is solved to yield an expression for the rate at which phonons scatter by the thin film boundaries in the presence of the other phonon scattering mechanisms. The rates at which phonons scatter via normal and resistive three-phonon processes are calculated by using perturbation theories with taking into account dispersion of confined acoustic phonons in a two dimensional structure. The vibrational parameters of the model are deduced from the dispersion of confined acoustic phonons as functions of temperature and crystallographic direction. The accuracy of the model is demonstrated with reference to recent experimental investigations regarding the thermal conductivity of single-crystal and polycrystalline SiGe films. The paper describes the strength of each of the phonon scattering mechanisms in the full temperature range. Furthermore, it predicts the alloy composition and film thickness that lead to minimum thermal conductivity in a single-crystal SiGe film, and the alloy composition and grain size that lead to minimum thermal conductivity in a polycrystalline SiGe film.

  19. Influencing factors on the size uniformity of self-assembled SiGe quantum rings grown by molecular beam epitaxy.

    Science.gov (United States)

    Cui, J; Lv, Y; Yang, X J; Fan, Y L; Zhong, Z; Jiang, Z M

    2011-03-25

    The size uniformity of self-assembled SiGe quantum rings, which are formed by capping SiGe quantum dots with a thin Si layer, is found to be greatly influenced by the growth temperature and the areal density of SiGe quantum dots. Higher growth temperature benefits the size uniformity of quantum dots, but results in low Ge concentration as well as asymmetric Ge distribution in the dots, which induces the subsequently formed quantum rings to be asymmetric in shape or even broken somewhere in the ridge of rings. Low growth temperature degrades the size uniformity of quantum dots, and thus that of quantum rings. A high areal density results in the expansion and coalescence of neighboring quantum dots to form a chain, rather than quantum rings. Uniform quantum rings with a size dispersion of 4.6% and an areal density of 7.8×10(8) cm(-2) are obtained at the optimized growth temperature of 640°C.

  20. Delayed plastic relaxation limit in SiGe islands grown by Ge diffusion from a local source

    Energy Technology Data Exchange (ETDEWEB)

    Vanacore, G. M.; Zani, M.; Tagliaferri, A., E-mail: alberto.tagliaferri@polimi.it [CNISM-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Nicotra, G. [IMM-CNR, Stradale Primosole 50, I-95121 Catania (Italy); Bollani, M. [CNR-IFN, LNESS, Via Anzani 42, I-22100 Como (Italy); Bonera, E.; Montalenti, F.; Picco, A.; Boioli, F. [Dipartimento di Scienza dei Materiali and L-NESS, Università Milano-Bicocca, via Cozzi 53, I-20125 Milano (Italy); Capellini, G. [Department of Sciences at the Università Roma Tre, Via Vasca Navale 79, 00146 Roma (Italy); Isella, G. [CNISM, LNESS, Dipartimento di Fisica, Politecnico di Milano (Polo di Como), Via Anzani 42, I-22100 Como (Italy); Osmond, J. [ICFO–The Institute of Photonic Sciences, Av. Carl Friedrich Gauss, 3, E-08860 Castelldefels (Barcelona) (Spain)

    2015-03-14

    The hetero-epitaxial strain relaxation in nano-scale systems plays a fundamental role in shaping their properties. Here, the elastic and plastic relaxation of self-assembled SiGe islands grown by surface-thermal-diffusion from a local Ge solid source on Si(100) are studied by atomic force and transmission electron microscopies, enabling the simultaneous investigation of the strain relaxation in different dynamical regimes. Islands grown by this technique remain dislocation-free and preserve a structural coherence with the substrate for a base width as large as 350 nm. The results indicate that a delay of the plastic relaxation is promoted by an enhanced Si-Ge intermixing, induced by the surface-thermal-diffusion, which takes place already in the SiGe overlayer before the formation of a critical nucleus. The local entropy of mixing dominates, leading the system toward a thermodynamic equilibrium, where non-dislocated, shallow islands with a low residual stress are energetically stable. These findings elucidate the role of the interface dynamics in modulating the lattice distortion at the nano-scale, and highlight the potential use of our growth strategy to create composition and strain-controlled nano-structures for new-generation devices.

  1. Atomistic simulations of thermal transport in Si and SiGe based materials: From bulk to nanostructures

    Science.gov (United States)

    Savic, Ivana; Mingo, Natalio; Donadio, Davide; Galli, Giulia

    2010-03-01

    It has been recently proposed that Si and SiGe based nanostructured materials may exhibit low thermal conductivity and overall promising properties for thermoelectric applications. Hence there is a considerable interest in developing accurate theoretical and computational methods which can help interpret recent measurements, identify the physical origin of the reduced thermal conductivity, as well as shed light on the interplay between disorder and nanostructuring in determining a high figure of merit. In this work, we investigate the capability of an atomistic Green's function method [1] to describe phonon transport in several types of Si and SiGe based systems: amorphous Si, SiGe alloys, planar and nanodot Si/SiGe multilayers. We compare our results with experimental data [2,3], and with the findings of molecular dynamics simulations and calculations based on the Boltzmann transport equation. [1] I. Savic, N. Mingo, and D. A. Stewart, Phys. Rev. Lett. 101, 165502 (2008). [2] S.-M. Lee, D. G. Cahill, and R. Venkatasubramanian, Appl. Phys. Lett. 70, 2957 (1997). [3] G. Pernot et al., submitted.

  2. Feasibility studies for a wireless 60 GHz tracking detector readout

    International Nuclear Information System (INIS)

    Dittmeier, S.; Schöning, A.; Soltveit, H.K.; Wiedner, D.

    2016-01-01

    The amount of data produced by highly granular silicon tracking detectors in high energy physics experiments poses a major challenge to readout systems. At high collision rates, e.g. at LHC experiments, only a small fraction of data can be read out with currently used technologies. To cope with the requirements of future or upgraded experiments new data transfer techniques are required which offer high data rates at low power and low material budget. Wireless technologies operating in the 60 GHz band or at higher frequencies offer high data rates and are thus a promising upcoming alternative to conventional data transmission via electrical cables or optical fibers. Using wireless technology, the amount of cables and connectors in detectors can be significantly reduced. Tracking detectors profit most from a reduced material budget as fewer secondary particle interactions (multiple Coulomb scattering, energy loss, etc.) improve the tracking performance in general. We present feasibility studies regarding the integration of the wireless technology at 60 GHz into a silicon tracking detector. We use spare silicon strip modules of the ATLAS experiment as test samples which are measured to be opaque in the 60 GHz range. The reduction of cross talk between links and the attenuation of reflections is studied. An estimate of the maximum achievable link density is given. It is shown that wireless links can be placed as close as 2 cm next to each other for a layer distance of 10 cm by exploiting one or several of the following measures: highly directive antennas, absorbers like graphite foam, linear polarization and frequency channeling. Combining these measures, a data rate area density of up to 11 Tb/(s·m"2) seems feasible. In addition, two types of silicon sensors are tested under mm-wave irradiation in order to determine the influence of 60 GHz data transmission on the detector performance: an ATLAS silicon strip sensor module and an HV-MAPS prototype for the Mu3e

  3. Amplifier Module for 260-GHz Band Using Quartz Waveguide Transitions

    Science.gov (United States)

    Padmanabhan, Sharmila; Fung, King Man; Kangaslahti, Pekka P.; Peralta, Alejandro; Soria, Mary M.; Pukala, David M.; Sin, Seth; Samoska, Lorene A.; Sarkozy, Stephen; Lai, Richard

    2012-01-01

    Packaging of MMIC LNA (monolithic microwave integrated circuit low-noise amplifier) chips at frequencies over 200 GHz has always been problematic due to the high loss in the transition between the MMIC chip and the waveguide medium in which the chip will typically be used. In addition, above 200 GHz, wire-bond inductance between the LNA and the waveguide can severely limit the RF matching and bandwidth of the final waveguide amplifier module. This work resulted in the development of a low-loss quartz waveguide transition that includes a capacitive transmission line between the MMIC and the waveguide probe element. This capacitive transmission line tunes out the wirebond inductance (where the wire-bond is required to bond between the MMIC and the probe element). This inductance can severely limit the RF matching and bandwidth of the final waveguide amplifier module. The amplifier module consists of a quartz E-plane waveguide probe transition, a short capacitive tuning element, a short wire-bond to the MMIC, and the MMIC LNA. The output structure is similar, with a short wire-bond at the output of the MMIC, a quartz E-plane waveguide probe transition, and the output waveguide. The quartz probe element is made of 3-mil quartz, which is the thinnest commercially available material. The waveguide band used is WR4, from 170 to 260 GHz. This new transition and block design is an improvement over prior art because it provides for better RF matching, and will likely yield lower loss and better noise figure. The development of high-performance, low-noise amplifiers in the 180-to- 700-GHz range has applications for future earth science and planetary instruments with low power and volume, and astrophysics array instruments for molecular spectroscopy. This frequency band, while suitable for homeland security and commercial applications (such as millimeter-wave imaging, hidden weapons detection, crowd scanning, airport security, and communications), also has applications to

  4. Feasibility studies for a wireless 60 GHz tracking detector readout

    Energy Technology Data Exchange (ETDEWEB)

    Dittmeier, S., E-mail: dittmeier@physi.uni-heidelberg.de; Schöning, A.; Soltveit, H.K.; Wiedner, D.

    2016-09-11

    The amount of data produced by highly granular silicon tracking detectors in high energy physics experiments poses a major challenge to readout systems. At high collision rates, e.g. at LHC experiments, only a small fraction of data can be read out with currently used technologies. To cope with the requirements of future or upgraded experiments new data transfer techniques are required which offer high data rates at low power and low material budget. Wireless technologies operating in the 60 GHz band or at higher frequencies offer high data rates and are thus a promising upcoming alternative to conventional data transmission via electrical cables or optical fibers. Using wireless technology, the amount of cables and connectors in detectors can be significantly reduced. Tracking detectors profit most from a reduced material budget as fewer secondary particle interactions (multiple Coulomb scattering, energy loss, etc.) improve the tracking performance in general. We present feasibility studies regarding the integration of the wireless technology at 60 GHz into a silicon tracking detector. We use spare silicon strip modules of the ATLAS experiment as test samples which are measured to be opaque in the 60 GHz range. The reduction of cross talk between links and the attenuation of reflections is studied. An estimate of the maximum achievable link density is given. It is shown that wireless links can be placed as close as 2 cm next to each other for a layer distance of 10 cm by exploiting one or several of the following measures: highly directive antennas, absorbers like graphite foam, linear polarization and frequency channeling. Combining these measures, a data rate area density of up to 11 Tb/(s·m{sup 2}) seems feasible. In addition, two types of silicon sensors are tested under mm-wave irradiation in order to determine the influence of 60 GHz data transmission on the detector performance: an ATLAS silicon strip sensor module and an HV-MAPS prototype for the Mu3e

  5. 105 GHz Notch Filter Design for Collective Thomson Scattering

    DEFF Research Database (Denmark)

    Furtula, Vedran; Michelsen, Poul; Leipold, Frank

    2011-01-01

    A millimeter-wave notch filter with 105-GHz center frequency, >20-GHz passband coverage, and 1-GHz rejection bandwidth has been constructed. The design is based on a fundamental rectangular waveguide with cylindrical cavities coupled by narrow iris gaps, i.e., small elongated holes of negligible...

  6. THz photonic wireless links with 16-QAM modulation in the 375-450 GHz band

    DEFF Research Database (Denmark)

    Jia, Shi; Yu, Xianbin; Hu, Hao

    2016-01-01

    forward error correction (HD-FEC) threshold of 3.8e-3 with 7% overhead. In addition, we also successfully demonstrate hybrid photonic wireless transmission of 40 Gbit/s 16-QAM signal at carrier frequencies of 400 GHz and 425 GHz over 30 km standard single mode fiber (SSMF) between the optical baseband...... signal transmitter and the THz wireless transmitter with negligible induced power penalty.......We propose and experimentally demonstrate THz photonic wireless communication systems with 16-QAM modulation in the 375-450 GHz band. The overall throughput reaches as high as 80 Gbit/s by exploiting four THz channels with 5 Gbaud 16-QAM baseband modulation per channel. We create a coherent optical...

  7. A 94 GHz CMOS based oscillator transmitter with an on-chip meandered dipole antenna

    KAUST Repository

    Cheema, Hammad M.

    2015-10-26

    A miniaturized 94 GHz oscillator transmitter in 65nm CMOS is presented. An extremely small silicon foot-print of 0.25mm2 is achieved through meandering of the top-metal dipole antenna, conjugate matching between the oscillator and the antenna without impedance matching elements and efficient placement of the oscillator circuit within the antenna. The antenna demonstrates bandwidth of 90 to 99 GHz (10%) and a gain of -6dBi. The use of parasitic aware antenna-circuit code-sign strategy results in an accurate measured oscillation frequency of 94.1 GHz. The oscillator exhibits a measured output power of -25 dBm, phase noise of -88 dBc/Hz at 1 MHz offset and consumes 8.4mW from a 1V supply. © 2015 IEEE.

  8. Initial tests of an 11.4 GHz magnicon amplifier

    International Nuclear Information System (INIS)

    Gold, S.H.; Sullivan, C.A.; Manheimer, W.M.; Hafizi, B.

    1994-01-01

    The magnicon, a scanning beam microwave amplifier related to the gyrocon, is a possible replacement for klystron amplifiers in future high-gradient linear accelerators. The magnicon circuit consists of a multicavity deflection system followed by an output cavity. The purpose of the deflection system is to spin up the electron beam phase-coherently to high transverse momentum. In order to do this, the deflection cavities employ rotating TM 11 modes, producing a gyrating electron beam whose centroid rotates about the cavity axis in synchronism with the advance in phase of the rf modes. The output cavity employs a cyclotron resonant mechanism to extract principally the transverse beam momentum. It employs an rf mode that rotates synchronously with the deflection cavity modes, and with the entry point of the electron beam into the output cavity, making possible a highly efficient interaction. The NRL magnicon uses a 100--200 A, 500 keV beam produced by a cold-cathode diode on the NRL Long-Pulse Accelerator Facility. The first cavity is externally driven at 5.7 GHz, while the output cavity is designed to produce megawatts of power at 11.4 GHz in the TM 210 mode. In this paper, the authors present a progress report on the NRL magnicon experiment. They will discuss the procedure used to cold test and calibrate the magnicon circuit, and present initial results from experimental operations

  9. Test results from the LLNL 250 GHz CARM experiment

    International Nuclear Information System (INIS)

    Kulke, B.; Caplan, M.; Bubp, D.; Houck, T.; Rogers, D.; Trimble, D.; VanMaren, R.; Westenskow, G.; McDermott, D.B.; Luhmann, N.C. Jr.; Danly, B.

    1991-01-01

    The authors have completed the initial phase of a 250 GHz CARM experiment, driven by the 2 MeV, 1 kA, 30 ns induction linac at the LLNL ARC facility. A non-Brillouin, solid, electron beam is generated from a flux-threaded, thermionic cathode. As the beam traverses a 10 kG plateau produced by a superconducting magnet, ten percent of the beam energy is converted into rotational energy in a bifilar helix wiggler that produces a spiraling, 50 G, transverse magnetic field. The beam is then compressed to a 5 mm diameter as it drifts into a 30 kG plateau. For the present experiment, the CARM interaction region consisted of a single Bragg section resonator, followed by a smooth-bore amplifier section. Using high-pass filters, they have observed broadband output signals estimated to be at the several megawatt level in the range 140 to over 230 GHz. This is consistent with operation as a superradiant amplifier. Simultaneously, they also observed K a band power levels near 3 MW

  10. Test results from the LLNL 250 GHz CARM experiment

    International Nuclear Information System (INIS)

    Kulke, B.; Caplan, M.; Bubp, D.; Houck, T.; Rogers, D.; Trimble, D.; VanMaren, R.; Westenskow, G.; McDermott, D.B.; Luhmann, N.C. Jr.; Danly, B.

    1991-05-01

    We have completed the initial phase of a 250 GHz CARM experiment, driven by the 2 MeV, 1 kA, 30 ns induction linac at the LLNL ARC facility. A non-Brillouin, solid, electron beam is generated from a flux-threaded, thermionic cathode. As the beam traverses a 10 kG plateau produced by a superconducting magnet, ten percent of the beam energy is converted into rotational energy in a bifilar helix wiggler that produces a spiraling, 50 G, transverse magnetic field. The beam is then compressed to a 5 mm diameter as it drifts into a 30 kG plateau. For the present experiment, the CARM interaction region consisted of a single Bragg section resonator, followed by a smooth-bore amplifier section. Using high-pass filters, we have observed broadband output signals estimated to be at the several megawatt level in the range 140 to over 230 GHz. This is consistent with operation as a superradiant amplifier. Simultaneously, we also observed K a band power levels near 3 MW

  11. 60 GHz wireless data transfer for tracker readout systems—first studies and results

    International Nuclear Information System (INIS)

    Dittmeier, S.; Berger, N.; Schöning, A.; Soltveit, H.K.; Wiedner, D.

    2014-01-01

    To allow highly granular trackers to contribute to first level trigger decisions or event filtering, a fast readout system with very high bandwidth is required. Space, power and material constraints, however, pose severe limitations on the maximum available bandwidth of electrical or optical data transfers. A new approach for the implementation of a fast readout system is the application of a wireless data transfer at a carrier frequency of 60 GHz. The available bandwidth of several GHz allows for data rates of multiple Gbps per link. 60 GHz transceiver chips can be produced with a small form factor and a high integration level. A prototype transceiver currently under development at the University of Heidelberg is briefly described in this paper. To allow easy and fast future testing of the chip's functionality, a bit error rate test has been developed with a commercially available transceiver. Crosstalk might be a big issue for a wireless readout system with many links in a tracking detector. Direct crosstalk can be avoided by using directive antennas, linearly polarized waves and frequency channeling. Reflections from tracking modules can be reduced by applying an absorbing material like graphite foam. Properties of different materials typically used in tracking detectors and graphite foam in the 60 GHz frequency range are presented. For data transmission tests, links using commercially available 60 GHz transmitters and receivers are used. Studies regarding crosstalk and the applicability of graphite foam, Kapton horn antennas and polarized waves are shown

  12. A fully-differential phase-locked loop frequency synthesizer for 60-GHz wireless communication

    International Nuclear Information System (INIS)

    Kuang Lixue; Chi Baoyong; Chen Lei; Wang Zhihua; Jia Wen

    2014-01-01

    A 40-GHz phase-locked loop (PLL) frequency synthesizer for 60-GHz wireless communication applications is presented. The electrical characteristics of the passive components in the VCO and LO buffers are accurately extracted with an electromagnetic simulator HFSS. A differential tuning technique is utilized in the voltage controlled oscillator (VCO) to achieve higher common-mode noise rejection and better phase noise performance. The VCO and the divider chain are powered by a 1.0 V supply while the phase-frequency detector (PFD) and the charge pump (CP) are powered by a 2.5 V supply to improve the linearity. The measurement results show that the total frequency locking range of the frequency synthesizer is from 37 to 41 GHz, and the phase noise from a 40 GHz carrier is −97.2 dBc/Hz at 1 MHz offset. Implemented in 65 nm CMOS, the synthesizer consumes a DC power of 62 mW, including all the buffers. (semiconductor integrated circuits)

  13. A fully-differential phase-locked loop frequency synthesizer for 60-GHz wireless communication

    Science.gov (United States)

    Lixue, Kuang; Baoyong, Chi; Lei, Chen; Wen, Jia; Zhihua, Wang

    2014-12-01

    A 40-GHz phase-locked loop (PLL) frequency synthesizer for 60-GHz wireless communication applications is presented. The electrical characteristics of the passive components in the VCO and LO buffers are accurately extracted with an electromagnetic simulator HFSS. A differential tuning technique is utilized in the voltage controlled oscillator (VCO) to achieve higher common-mode noise rejection and better phase noise performance. The VCO and the divider chain are powered by a 1.0 V supply while the phase-frequency detector (PFD) and the charge pump (CP) are powered by a 2.5 V supply to improve the linearity. The measurement results show that the total frequency locking range of the frequency synthesizer is from 37 to 41 GHz, and the phase noise from a 40 GHz carrier is -97.2 dBc/Hz at 1 MHz offset. Implemented in 65 nm CMOS, the synthesizer consumes a DC power of 62 mW, including all the buffers.

  14. 10 GHz ECRIS for Warsaw Cyclotron

    CERN Document Server

    Sudlitz, K

    1999-01-01

    Cusp type, 10 GHz ECRIS has been built and tested earlier. For obtaining intensive beams, more relevant for cyclotron, cusp geometry has been replaced by hexapole. Discharge chamber (stainless steel, 50 mm diameter, 250 mm long) is an extension of a coaxial line, feeding RF (9,6 GHz, up to 200 W) to the plasma. The NdFeB hexapole (0,52 T on the surface) has been used. The axial magnetic field is created by water cooled coils. The axial injection line dedicated to K160 isochronous heavy ion cyclotron has been constructed. The line consists of Glaser lenses, double focusing magnet, solenoid and mirror type inflector. The system provides sufficient transmission of the beam from ECR ion source to the firsts orbits of the cyclotron for m/q ranging from 7 to 2. After successful initial tests which were done in July 1997 the ECRIS serves as an external source for Warsaw Cyclotron.

  15. Properties of laser-crystallized polycrystalline SiGe thin films

    Energy Technology Data Exchange (ETDEWEB)

    Weizman, Moshe

    2008-06-06

    In this thesis, structural, electrical, and optical properties of laser-crystallized polycrystalline Si{sub 1-x}Ge{sub x} thin films with 0SiGe samples that are exposed to a single laser pulse exhibit a ripple structure that evolves into a hillock structure when the samples are irradiated with additional laser pulses. - It is maintained that the main mechanism behind the structure formation is an instability of the propagating solid-liquid interface during solidification. - The study of defects with electron spin resonance showed that laser-crystallized poly-Si{sub 1-x}Ge{sub x} thin films with 0SiGe films was lower and amounted to N{sub s}=7 x 10{sup 17} cm{sup -3}. - Germanium-rich laser-crystallized poly-SiGe thin films exhibited mostly a broad atypical electric dipole spin resonance (EDSR) signal that was accompanied by a nearly temperature-independent electrical conductivity in the range 20-100 K. - Most likely, the origin of the grain boundary conductance is due to dangling-bond defects and not impurities. Metallic-like conductance occurs when the dangling-bond defect density is above a critical value of about N{sub C} {approx} 10{sup 18} cm{sup -3}. - Laser crystallized poly-Si{sub 1-x}Ge{sub x} thin films with x{>=}0.5 exhibit optical absorption behavior that is characteristic for disordered SiGe, implying that the absorption occurs primarily at the grain boundaries. A sub-band-gap absorption peak was found for

  16. Secondary growth mechanism of SiGe islands deposited on a mixed-phase microcrystalline Si by ion beam co-sputtering.

    Science.gov (United States)

    Ke, S Y; Yang, J; Qiu, F; Wang, Z Q; Wang, C; Yang, Y

    2015-11-06

    We discuss the SiGe island co-sputtering deposition on a microcrystalline silicon (μc-Si) buffer layer and the secondary island growth based on this pre-SiGe island layer. The growth phenomenon of SiGe islands on crystalline silicon (c-Si) is also investigated for comparison. The pre-SiGe layer grown on μc-Si exhibits a mixed-phase structure, including SiGe islands and amorphous SiGe (a-SiGe) alloy, while the layer deposited on c-Si shows a single-phase island structure. The preferential growth and Ostwald ripening growth are shown to be the secondary growth mechanism of SiGe islands on μc-Si and c-Si, respectively. This difference may result from the effect of amorphous phase Si (AP-Si) in μc-Si on the island growth. In addition, the Si-Ge intermixing behavior of the secondary-grown islands on μc-Si is interpreted by constructing the model of lateral atomic migration, while this behavior on c-Si is ascribed to traditional uphill atomic diffusion. It is found that the aspect ratios of the preferential-grown super islands are higher than those of the Ostwald-ripening ones. The lower lateral growth rate of super islands due to the lower surface energy of AP-Si on the μc-Si buffer layer for the non-wetting of Ge at 700 °C and the stronger Si-Ge intermixing effect at 730 °C may be responsible for this aspect ratio difference.

  17. Q-Band (37-41 GHz) Satellite Beacon Architecture for RF Propagation Experiments

    Science.gov (United States)

    Simmons, Rainee N.; Wintucky, Edwin G.

    2012-01-01

    In this paper, the design of a beacon transmitter that will be flown as a hosted payload on a geostationary satellite to enable propagation experiments at Q-band (37-41 GHz) frequencies is presented. The beacon uses a phased locked loop stabilized dielectric resonator oscillator and a solid-state power amplifier to achieve the desired output power. The satellite beacon antenna is configured as an offset-fed cut-paraboloidal reflector.

  18. Q-Band (37 to 41 GHz) Satellite Beacon Architecture for RF Propagation Experiments

    Science.gov (United States)

    Simons, Rainee N.; Wintucky, Edwin G.

    2014-01-01

    In this paper, the design of a beacon transmitter that will be flown as a hosted payload on a geostationary satellite to enable propagation experiments at Q-band (37 to 41 GHz) frequencies is presented. The beacon uses a phased locked loop stabilized dielectric resonator oscillator and a solid-state power amplifier to achieve the desired output power. The satellite beacon antenna is configured as an offset-fed cutparaboloidal reflector.

  19. Operation of a 1.3 GHz, 10 MW Multiple Beam Klystron

    CERN Document Server

    Bohlen, H P; Cattelino, M; Cox, L; Cusick, M; Forrest, S; Friedlander, F; Staprans, A; Wright, E; Zitelli, L

    2004-01-01

    Results will be reported for a 1.3 GHz, 10 MW multiple beam klystron that is being developed for the TESLA linear accelerator facility. The design parameters for the device are 10 MW peak RF output power with 150 kW average power, 1.5 ms pulse length, 65% efficiency, 50 dB gain, and 2.0 A/cm2

  20. Use of the 37-38 GHz and 40-40.5 GHz Ka-bands for Deep Space Communications

    Science.gov (United States)

    Morabito, David; Hastrup, Rolf

    2004-01-01

    This paper covers a wide variety of issues associated with the implementation and use of these frequency bands for deep space communications. Performance issues, such as ground station pointing stability, ground antenna gain, antenna pattern, and propagation effects such as due to atmospheric, charged-particle and space loss at 37 GHz, will be addressed in comparison to the 32 GHz Ka-band deep space allocation. Issues with the use of and competition for this spectrum also will be covered. The state of the hardware developed (or proposed) for operating in this frequency band will be covered from the standpoint of the prospects for achieving higher data rates that could be accommodated in the available bandwidth. Hardware areas to be explored include modulators, digital-to-analog converters, filters, power amplifiers, receivers, and antennas. The potential users of the frequency band will be explored as well as their anticipated methods to achieve the potential high data rates and the implications of the competition for bandwidth.

  1. 60 GHz gyrotron development program. Final report, April 1979-June 1984

    International Nuclear Information System (INIS)

    Shively, J.F.; Bier, R.E.; Caplan, M.

    1986-01-01

    The original objective of this program was to develop a microwave amplifier or oscillator capable of producing 200 kW CW power output at 110 GHz. The use of cyclotron resonance interaction was pursued, and the design phases of this effort are discussed. Later, however, the program's objective was changed to develop a family of oscillators capable of producing 200 kw of peak output power at 60 GHz. Gyrotron behavior studies were performed at 28 GHz to obtain generic design information as quickly as possible. The first experimental device at 60 GHz produced over 200 kw of peak power at a pulse duration of 20 μs. Heating problems and mode interference were encountered. The second experimental tube incorporated an optimized gun location but also suffered from mode interference. The third experimental tube included modifications that reduced mode interference. It demonstrated 200 kw of peak output at 100 ms pulse duration. The fourth experimental tube, which used an older rf circuit design but in a CW configuration, produced 71.5 kW CW. The fifth experimental tube incorporated a thinner double-disc output window which improved window bandwidth and reduced window loss. This tube also incorporated modifications to the drift tunnel and cavity coupling, which had proven successful in the third experimental pulse tube tests. It produced 123 kW of CW output power at 60 GHz rf load coolant boiling and tube window failure terminated the tests. A new waterload was designed and constructed, and alternative window designs were explored

  2. Experiments on a 14.5 GHz ECR source

    International Nuclear Information System (INIS)

    Hill, C.E.; Langbein, K.

    1996-01-01

    The 14.5 GHz ECR4 source supplied to CERN in the framework of the Heavy Ion Facility collaboration provided Pb 27+ operational beams to a new custom built linac in 1994. This source, which operates in the pulsed 'afterglow' mode, quickly met its design specification of 80 eμA and now provides currents >100 eμA regularly. Early source tests showed the existence of extremely stable modes of operation. In the search for higher intensities a number of experiments have been performed on plasma gas composition, RF power matching, extraction, beam pulse compression and a biased dynode. The results of these tests will be presented along with further ideas to improve source performance. (author)

  3. Feasibility studies for a wireless 60 GHz tracking detector readout

    CERN Document Server

    Dittmeier, Sebastian; Soltveit, Hans Kristian; Wiedner, Dirk

    2016-01-01

    The amount of data produced by highly granular silicon tracking detectors in high energy physics experiments poses a major challenge to readout systems. At high collision rates, e.g. at LHC experiments, only a small fraction of data can be read out with currently used technologies. To cope with the requirements of future or upgraded experiments new data transfer techniques are required which offer high data rates at low power and low material budget. Wireless technologies operating in the 60 GHz band or at higher frequencies offer high data rates and are thus a promising upcoming alternative to conventional data transmission via electrical cables or optical fibers. Using wireless technology, the amount of cables and connectors in detectors can be significantly reduced. Tracking detectors profit most from a reduced material budget as fewer secondary particle interactions (multiple Coulomb scattering, energy loss, etc.) improve the tracking performance in general. We present feasibility studies regarding the in...

  4. Suspended mid-infrared fiber-to-chip grating couplers for SiGe waveguides

    Science.gov (United States)

    Favreau, Julien; Durantin, Cédric; Fédéli, Jean-Marc; Boutami, Salim; Duan, Guang-Hua

    2016-03-01

    Silicon photonics has taken great importance owing to the applications in optical communications, ranging from short reach to long haul. Originally dedicated to telecom wavelengths, silicon photonics is heading toward circuits handling with a broader spectrum, especially in the short and mid-infrared (MIR) range. This trend is due to potential applications in chemical sensing, spectroscopy and defense in the 2-10 μm range. We previously reported the development of a MIR photonic platform based on buried SiGe/Si waveguide with propagation losses between 1 and 2 dB/cm. However the low index contrast of the platform makes the design of efficient grating couplers very challenging. In order to achieve a high fiber-to-chip efficiency, we propose a novel grating coupler structure, in which the grating is locally suspended in air. The grating has been designed with a FDTD software. To achieve high efficiency, suspended structure thicknesses have been jointly optimized with the grating parameters, namely the fill factor, the period and the grating etch depth. Using the Efficient Global Optimization (EGO) method we obtained a configuration where the fiber-to-waveguide efficiency is above 57 %. Moreover the optical transition between the suspended and the buried SiGe waveguide has been carefully designed by using an Eigenmode Expansion software. Transition efficiency as high as 86 % is achieved.

  5. Diffusion Mechanisms and Lattice Locations of Thermal-Equilibrium Defects in Si-Ge Alloys

    CERN Multimedia

    Lyutovich, K; Touboltsev, V; Laitinen, P O; Strohm, A

    2002-01-01

    It is generally accepted that Ge and Si differ considerably with respect to intrinsic-point-defect-mediated diffusion. In Ge, the native point defects dominating under thermal-equilibium conditions at all solid-state temperatures accessible in diffusion experiments are vacancies, and therefore Ge self-diffusion is vacancy-controlled. In Si, by contrast, self-interstitials and vacancies co-exist in thermal equilibrium. Whereas in the most thoroughly investigated temperature regime above about 1000$^\\circ$C Si self-diffusion is self-interstitial-controlled, it is vacancy-controlled at lower temperatures. According to the scenario displayed above, self-diffusion in Si-Ge alloys is expected to change from an interstitialcy mechanism on the Si side to a vacancy mechanism on the Ge side. Therefore, $^{71}$Ge self-diffusion experiments in Si$_{1- \\it y}$Ge$_{\\it y}$ as a function of composition Y are highly interesting. In a first series of experiments the diffusion of Ge in 0.4 to 10 $\\mu$m thick, relaxed, low-disl...

  6. Thin SiGe virtual substrates for Ge heterostructures integration on silicon

    International Nuclear Information System (INIS)

    Cecchi, S.; Chrastina, D.; Frigerio, J.; Isella, G.; Gatti, E.; Guzzi, M.; Müller Gubler, E.; Paul, D. J.

    2014-01-01

    The possibility to reduce the thickness of the SiGe virtual substrate, required for the integration of Ge heterostructures on Si, without heavily affecting the crystal quality is becoming fundamental in several applications. In this work, we present 1 μm thick Si 1−x Ge x buffers (with x > 0.7) having different designs which could be suitable for applications requiring a thin virtual substrate. The rationale is to reduce the lattice mismatch at the interface with the Si substrate by introducing composition steps and/or partial grading. The relatively low growth temperature (475 °C) makes this approach appealing for complementary metal-oxide-semiconductor integration. For all the investigated designs, a reduction of the threading dislocation density compared to constant composition Si 1−x Ge x layers was observed. The best buffer in terms of defects reduction was used as a virtual substrate for the deposition of a Ge/SiGe multiple quantum well structure. Room temperature optical absorption and photoluminescence analysis performed on nominally identical quantum wells grown on both a thick graded virtual substrate and the selected thin buffer demonstrates a comparable optical quality, confirming the effectiveness of the proposed approach

  7. Thermal transport in nanocrystalline Si and SiGe by ab initio based Monte Carlo simulation.

    Science.gov (United States)

    Yang, Lina; Minnich, Austin J

    2017-03-14

    Nanocrystalline thermoelectric materials based on Si have long been of interest because Si is earth-abundant, inexpensive, and non-toxic. However, a poor understanding of phonon grain boundary scattering and its effect on thermal conductivity has impeded efforts to improve the thermoelectric figure of merit. Here, we report an ab-initio based computational study of thermal transport in nanocrystalline Si-based materials using a variance-reduced Monte Carlo method with the full phonon dispersion and intrinsic lifetimes from first-principles as input. By fitting the transmission profile of grain boundaries, we obtain excellent agreement with experimental thermal conductivity of nanocrystalline Si [Wang et al. Nano Letters 11, 2206 (2011)]. Based on these calculations, we examine phonon transport in nanocrystalline SiGe alloys with ab-initio electron-phonon scattering rates. Our calculations show that low energy phonons still transport substantial amounts of heat in these materials, despite scattering by electron-phonon interactions, due to the high transmission of phonons at grain boundaries, and thus improvements in ZT are still possible by disrupting these modes. This work demonstrates the important insights into phonon transport that can be obtained using ab-initio based Monte Carlo simulations in complex nanostructured materials.

  8. SiGe HBT cryogenic preamplification for higher bandwidth donor spin read-out

    Science.gov (United States)

    Curry, Matthew; Carr, Stephen; Ten-Eyck, Greg; Wendt, Joel; Pluym, Tammy; Lilly, Michael; Carroll, Malcolm

    2014-03-01

    Single-shot read-out of a donor spin can be performed using the response of a single-electron-transistor (SET). This technique can produce relatively large changes in current, on the order of 1 (nA), to distinguish between the spin states. Despite the relatively large signal, the read-out time resolution has been limited to approximately 100 (kHz) of bandwidth because of noise. Cryogenic pre-amplification has been shown to extend the response of certain detection circuits to shorter time resolution and thus higher bandwidth. We examine a SiGe HBT circuit configuration for cryogenic preamplification, which has potential advantages over commonly used HEMT configurations. Here we present 4 (K) measurements of a circuit consisting of a Silicon-SET inline with a Heterojunction-Bipolar-Transistor (HBT). We compare the measured bandwidth with and without the HBT inline and find that at higher frequencies the signal-to-noise-ratio (SNR) with the HBT inline exceeds the SNR without the HBT inline. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE, Office of Basic Energy Sciences user facility. The work was supported by the Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

  9. Homogeneous SiGe crystal growth in microgravity by the travelling liquidus-zone method

    International Nuclear Information System (INIS)

    Kinoshita, K; Arai, Y; Inatomi, Y; Sakata, K; Takayanagi, M; Yoda, S; Miyata, H; Tanaka, R; Sone, T; Yoshikawa, J; Kihara, T; Shibayama, H; Kubota, Y; Shimaoka, T; Warashina, Y

    2011-01-01

    Homogeneous SiGe crystal growth experiments will be performed on board the ISS 'Kibo' using a gradient heating furnace (GHF). A new crystal growth method invented for growing homogeneous mixed crystals named 'travelling liquidus-zone (TLZ) method' is evaluated by the growth of Si 0.5 Ge 0.5 crystals in space. We have already succeeded in growing homogeneous 2mm diameter Si 0.5 Ge 0.5 crystals on the ground but large diameter homogeneous crystals are difficult to be grown due to convection in a melt. In microgravity, larger diameter crystals can be grown with suppressing convection. Radial concentration profiles as well as axial profiles in microgravity grown crystals will be measured and will be compared with our two-dimensional TLZ growth model equation and compositional variation is analyzed. Results are beneficial for growing large diameter mixed crystals by the TLZ method on the ground. Here, we report on the principle of the TLZ method for homogeneous crystal growth, results of preparatory experiments on the ground and plan for microgravity experiments.

  10. LAPAS: A SiGe Front End Prototype for the Upgraded ATLAS LAr Calorimeter

    CERN Document Server

    Dressnandt, N; Rescia, S; Vernon, E

    2009-01-01

    We have designed and fabricated a very low noise preamplifier and shaper to replace the existing ATLAS Liquid Argon readout for use at the Large Hadron Collider upgrade (sLHC). IBM’s 8WL 130nm SiGe process was chosen for it’s radiation tolerance, low noise bipolar NPN devices, wide voltage rand and potential use in other sLHC detector subsystems. Although the requirements for the final design can not be set at this time, the prototype was designed to accommodate a 16 bit dynamic range. This was accomplished by using a single stage, low noise, wide dynamic range preamp followed by a dual range shaper. The low noise of the preamp is made possible by the low base spreading resistance of the Silicon Germanium NPN bipolar transistors. The relatively high voltage rating of the NPN transistors is exploited to allow a gain of 650V/A in the preamplifier which eases the input voltage noise requirement on the shaper. Each shaper stage is designed as a cascaded differential operational amplifier doublet with a common...

  11. LAPAS: A SiGe Front End Prototype for the Upgraded ATLAS LAr

    CERN Document Server

    Rescia, S; Newcomer, F M; Dressnandt, N

    2009-01-01

    We have designed and fabricated a very low noise preamplifier and shaper with a (RC)2 – CR response to replace the existing ATLAS Liquid Argon readout for use at SLHC. IBM’s 8WL 130nm SiGe process was chosen for its radiation tolerance wide voltage range and potential for use in other LHC detector subsystems. The required dynamic range of 15 bits is accomplished by utilization of a single stage, low noise, wide dynamic range preamp connected to a dual range shaper. The low noise of the preamp (~.01nA / √Hz) is achieved by utilizing the process Silicon Germanium bipolar transistors. The relatively high voltage rating of the npn transistors is exploited to allow a gain of 650V/A. With this gain the equivalent input voltage noise requirement on the shaper to about 2.2nV/ √Hz. Each shaper stage is designed as a cascaded differential op amp doublet with a common mode operating point regulated by an internal feedback loop. The shaper outputs are designed to be compatible with the 130nm CMOS ADC being develo...

  12. Thermal boundary resistance at Si/Ge interfaces by molecular dynamics simulation

    Directory of Open Access Journals (Sweden)

    Tianzhuo Zhan

    2015-04-01

    Full Text Available In this study, we investigated the temperature dependence and size effect of the thermal boundary resistance at Si/Ge interfaces by non-equilibrium molecular dynamics (MD simulations using the direct method with the Stillinger-Weber potential. The simulations were performed at four temperatures for two simulation cells of different sizes. The resulting thermal boundary resistance decreased with increasing temperature. The thermal boundary resistance was smaller for the large cell than for the small cell. Furthermore, the MD-predicted values were lower than the diffusion mismatch model (DMM-predicted values. The phonon density of states (DOS was calculated for all the cases to examine the underlying nature of the temperature dependence and size effect of thermal boundary resistance. We found that the phonon DOS was modified in the interface regions. The phonon DOS better matched between Si and Ge in the interface region than in the bulk region. Furthermore, in interface Si, the population of low-frequency phonons was found to increase with increasing temperature and cell size. We suggest that the increasing population of low-frequency phonons increased the phonon transmission coefficient at the interface, leading to the temperature dependence and size effect on thermal boundary resistance.

  13. Influence of irradiation on mechanical properties of Si-Ge alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sichinava, Avtandil; Bokuchava, Guram; Chubinidze, Giorgi; Archuadze, Giorgi [Ilia Vekua Sukhumi Institute of Physics and Technology, Tbilisi (Georgia); Gapishvili, Nodar [Ilia Vekua Sukhumi Institute of Physics and Technology, Tbilisi (Georgia); Georgian Technical University, Tbilisi (Georgia)

    2017-07-15

    Impact of various irradiation (Ar and He ions, high energy electrons) on microhardness and indentation of monocrystalline Si{sub 0,98}Ge{sub 0,02} alloy is studied. Samples of Si and SiGe alloy are obtained by Czochralski (CZ) method in the [111] direction in the atmosphere of high purity Ar. High energy electron irradiation with fluence of ∝10{sup 12} cm{sup -2} is conducted at the Clinac 2100iX. Ar and He ion implantation is performed on modernized ''VEZUVI-3M'' plant. It is shown that for all types of irradiation the microhardness and indentation modulus versus load are characterized by reverse indentation size effect (ISE). With the increase of fluences of Ar and He ions, the maximum value of the effect increases. At high values of loading force impact on the indenter the mechanical characteristics slowly decrease. Impact of isochronous thermal annealing on mechanical properties of high energy electron irradiated samples is studied. Non-monotonic changes of microhardness and indentation modulus are revealed in the temperature range of 200-260 C. It is proposed that such changes are caused by radiation defects transformation. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Practice guidelines on the use of esophageal manometry - A GISMAD-SIGE-AIGO medical position statement.

    Science.gov (United States)

    Savarino, Edoardo; de Bortoli, Nicola; Bellini, Massimo; Galeazzi, Francesca; Ribolsi, Mentore; Salvador, Renato; Savarino, Vincenzo; Penagini, Roberto

    2016-10-01

    Patients with esophageal symptoms potentially associated to esophageal motor disorders such as dysphagia, chest pain, heartburn and regurgitation, represent one of the most frequent reasons for referral to gastroenterological evaluation. The utility of esophageal manometry in clinical practice is: (1) to accurately define esophageal motor function, (2) to identify abnormal motor function, and (3) to establish a treatment plan based on motor abnormalities. With this in mind, in the last decade, investigations and technical advances, with the introduction of high-resolution esophageal manometry, have enhanced our understanding and management of esophageal motility disorders. The following recommendations were developed to assist physicians in the appropriate use of esophageal manometry in modern patient care. They were discussed and approved after a comprehensive review of the medical literature pertaining to manometric techniques and their recent application. This position statement created under the auspices of the Gruppo Italiano di Studio per la Motilità dell'Apparato Digerente (GISMAD), Società Italiana di Gastroenterologia ed Endoscopia Digestiva (SIGE) and Associazione Italiana Gastroenterologi ed Endoscopisti Digestivi Ospedalieri (AIGO) is intended to help clinicians in applying manometric studies in the most fruitful manner within the context of their patients with esophageal symptoms. Copyright © 2016 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  15. HTS microstrip disk resonator with an upper dielectric layer for 4GHz

    International Nuclear Information System (INIS)

    Yamanaka, Kazunori; Kai, Manabu; Akasegawa, Akihiko; Nakanishi, Teru

    2006-01-01

    We propose HTS microstrip disk resonator with an upper dielectric layer as a candidate resonator structure of HTS compact power filter for 4GHz band. The electromagnetic simulations on the upper dielectric layer examined the current distributions of the HTS resonators that had TM 11 mode resonance of about 4 GHz. By the simulations, it is evaluated that of the maximum current density near the end portion of the disk-shape pattern of the resonator with the thick upper-layered structure decreases by roughly 30-50 percent, as compared with that of the resonator without it. Then, we designed and fabricated the resonator samples with and without the upper dielectrics. The RF power measurement results indicated that the upper dielectric layer leads to an increase in handling power

  16. An FDMA system concept for 30/20 GHz high capacity domestic satellite service

    Science.gov (United States)

    Berk, G.; Jean, P. N.; Rotholz, E.; White, B. E.

    1982-01-01

    The paper summarizes a feasibility study of a multibeam FDMA satellite system operating in the 30/20 GHz band. The system must accommodate a very high volume of traffic within the restrictions of a 5 kW solar cell array and a 2.5 GHz bandwidth. Multibeam satellite operation reduces the DC power demand and allows reuse of the available bandwidth. Interferences among the beams are brought to acceptable levels by appropriate frequency assignments. A transponder design is presented; it is greatly simplified by the application of a regional concept. System analysis shows that MSK modulation is appropriate for a high-capacity system because it conserves the frequency spectrum. Rain attenuation, a serious problem in this frequency band, is combatted with sufficient power margins and with coding. Link budgets, cost analysis, and weight and power calculations are also discussed. A satellite-routed FDMA system compares favorably in performance and cost with a satellite-switched TDMA system.

  17. First lasing of the Dutch Fusion-FEM: 730 kW, 200 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Urbanus, W.H. E-mail: urbanus@rijnh.nl; Bongers, W.A.; Geer, C.A.J. van der; Manintveld, P.; Plomp, J.; Pluygers, J.; Poelman, A.J.; Smeets, P.H.M.; Schueller, F.C.; Verhoeven, A.G.A.; Bratman, V.L.; Denisov, G.G.; Savilov, A.V.; Shmelyov, M.Yu.; Caplan, M.; Varfolomeev, A.A

    1999-06-01

    A high-power electrostatic free-electron maser is operated at various frequencies. An output power of 730 kW at 206 GHz is generated with a 7.2 A, 1.77 MeV electron beam, and 360 kW at 167 GHz is generated with a 7.0 A, 1.61 MeV electron beam. It is shown experimentally and by simulations that, depending on the electron beam energy, the FEM can operate in single-frequency regime. First experiments were done without electron beam energy recovery system, and the pulse length was limited to 12 {mu}s. Nevertheless, many aspects of generation of mm-wave power have been explored, such as the dependency on the electron beam energy and beam current and cavity settings such as the feedback coefficient. The achieved parameters and the FEM dynamics are in good accordance with simulations.

  18. A study of parametric instability in a harmonic gyrotron: Designs of third harmonic gyrotrons at 94 GHz and 210 GHz

    International Nuclear Information System (INIS)

    Saraph, G.P.; Antonsen, T.M. Jr.; Nusinovich, G.S.; Levush, B.

    1995-01-01

    Mode competition can present a major hurdle in achieving stable, efficient operation of a gyrotron at the cyclotron harmonics. A type of mode interaction in which three modes at different cyclotron harmonics are parametrically coupled together is analyzed here. This coupling can lead to parametric excitation or suppression of a mode; cyclic mode hopping; or the coexistence of three modes. Simulation results are presented for the parametric instability involving modes at the fundamental, second harmonic, and third harmonic of the cyclotron frequency. It is shown that the parametric excitation can lead to stable, efficient operation of a high-power gyrotron at the third harmonic. Based on this phenomenon, two practical designs are presented here for the third harmonic operation at 94 and 210 GHz. copyright 1995 American Institute of Physics

  19. The Development of Si and SiGe Technologies for Microwave and Millimeter-Wave Integrated Circuits

    Science.gov (United States)

    Ponchak, George E.; Alterovitz, Samuel A.; Katehi, Linda P. B.; Bhattacharya, Pallab K.

    1997-01-01

    Historically, microwave technology was developed by military and space agencies from around the world to satisfy their unique radar, communication, and science applications. Throughout this development phase, the sole goal was to improve the performance of the microwave circuits and components comprising the systems. For example, power amplifiers with output powers of several watts over broad bandwidths, low noise amplifiers with noise figures as low as 3 dB at 94 GHz, stable oscillators with low noise characteristics and high output power, and electronically steerable antennas were required. In addition, the reliability of the systems had to be increased because of the high monetary and human cost if a failure occurred. To achieve these goals, industry, academia and the government agencies supporting them chose to develop technologies with the greatest possibility of surpassing the state of the art performance. Thus, Si, which was already widely used for digital circuits but had material characteristics that were perceived to limit its high frequency performance, was bypassed for a progression of devices starting with GaAs Metal Semiconductor Field Effect Transistors (MESFETs) and ending with InP Pseudomorphic High Electron Mobility Transistors (PHEMTs). For each new material or device structure, the electron mobility increased, and therefore, the high frequency characteristics of the device were improved. In addition, ultra small geometry lithographic processes were developed to reduce the gate length to 0.1 pm which further increases the cutoff frequency. The resulting devices had excellent performance through the millimeter-wave spectrum.

  20. Low Power Digital Clock Design Using LVCMOS Input/Output Standards on 45nm FPGA

    DEFF Research Database (Denmark)

    Pandey, Sujeet; Mehta, Rishabh; Kalia, Kartik

    2016-01-01

    metal oxide semiconductor i.e. LVCMOS and 45nm Spartan-6 FPGA family is used for simulation and amount of total power consumed is noted down. There is 90.02%, 98.88%, 99.86% and 100% reduction in the clock when we scale down frequency from 100GHz to 10GHz, 1GHz, 0.1GHz, and 0.01GHz respectively....

  1. The Atacama Cosmology Telescope: Extragalactic Sources at 148 GHz in the 2008 Survey

    Science.gov (United States)

    Marriage, T. A.; Juin, J. B.; Lin, Y. T.; Marsden, D.; Nolta, M. R.; Partridge, B.; Ade, P. A. R.; Aguirre, P.; Amiri, M.; Appel, J. W.; hide

    2011-01-01

    We report on extragalactic sources detected in a 455 square-degree map of the southern sky made with data at a frequency of 148 GHz from the Atacama Cosmology Telescope 2008 observing season. We provide a catalog of 157 sources with flux densities spanning two orders of magnitude: from 15 mJy to 1500 mJy. Comparison to other catalogs shows that 98% of the ACT detections correspond to sources detected at lower radio frequencies. Three of the sources appear to be associated with the brightest cluster galaxies of low redshift X-ray selected galaxy clusters. Estimates of the radio to mm-wave spectral indices and differential counts of the sources further bolster the hypothesis that they are nearly all radio sources, and that their emission is not dominated by re-emission from warm dust. In a bright (> 50 mJy) 148 GHz-selected sample with complete cross-identifications from the Australia Telescope 20 GHz survey, we observe an average steepening of the spectra between .5, 20, and 148 GHz with median spectral indices of alp[ha (sub 5-20) = -0.07 +/- 0.06, alpha (sub 20-148) -0.39 +/- 0.04, and alpha (sub 5-148) = -0.20 +/- 0.03. When the measured spectral indices are taken into account, the 148 GHz differential source counts are consistent with previous measurements at 30 GHz in the context of a source count model dominated by radio sources. Extrapolating with an appropriately rescaled model for the radio source counts, the Poisson contribution to the spatial power spectrum from synchrotron-dominated sources with flux density less than 20 mJy is C(sup Sync) = (2.8 +/- 0.3) x 1O (exp-6) micro K(exp 2).

  2. Electron gun simulation for 95 GHz gyrotron

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Udaybir; Kumar, Nitin; Sinha, A.K., E-mail: uday.ceeri@gmail.com, E-mail: aksinha@ceeri.ernet.in [Gyrotron Laboratory, Microwave Tube Area, Central Electronics Engineering Research Institute, Pilani (India); Purohit, L.P. [Department of Physics, Gurukul Kangri Vishwavidyalaya, Haridwar (India)

    2011-07-01

    A triode type Magnetron Injection Gun (MIG) for a 2 MW, 95 GHz Gyrotron has been designed by using commercially available code EGUN and another in-house developed code MIGANS. The operating mode of the gyrotron is TE{sub 24.8} and it is operated in the fundamental harmonic. The operating voltages of the modulating anode and the accelerating anode are 61 kV and 85 kV respectively. The parametric dependences of modulating anode voltage and cathode magnetic field on the beam quality have also been studied. (author)

  3. Electron gun simulation for 95 GHz gyrotron

    International Nuclear Information System (INIS)

    Singh, Udaybir; Kumar, Nitin; Sinha, A.K.; Purohit, L.P.

    2011-01-01

    A triode type Magnetron Injection Gun (MIG) for a 2 MW, 95 GHz Gyrotron has been designed by using commercially available code EGUN and another in-house developed code MIGANS. The operating mode of the gyrotron is TE 24.8 and it is operated in the fundamental harmonic. The operating voltages of the modulating anode and the accelerating anode are 61 kV and 85 kV respectively. The parametric dependences of modulating anode voltage and cathode magnetic field on the beam quality have also been studied. (author)

  4. Surveys of radio sources at 5 GHz

    International Nuclear Information System (INIS)

    Pauliny-Toth, I.I.K.

    1977-01-01

    A number of surveys have been carried out at a frequency of 5 GHz at the National Radio Astronomy Observatory (NRAO) and at the Max-Planck-Institut fuer Radioastronomy (MPIFR) with the aim of determining the number-flux density relation for the sources detected and also of obtaining their radio spectra and optical identifications. The surveys fall into two categories: first, the strong source (S) surveys which are intended in due course to cover the whole northern sky and to be complete above a flux density of about 0.6 Jy; second, surveys of limited areas of sky down to lower levels of the flux density. (Auth.)

  5. Digital Predistortion of 75-110GHzW-Band Frequency Multiplier for Fiber Wireless Short Range Access Systems

    DEFF Research Database (Denmark)

    Zhao, Ying; Pang, Xiaodan; Deng, Lei

    2011-01-01

    We present a digital predistortion technique to effectively compensate high nonlinearity of a sextuple multiplier operating at 99.6GHz. An 18.9dB adjacent-channel power ratio (ACPR) improvement is guaranteed and a W-band fiber-wireless system is experimentally investigated.......We present a digital predistortion technique to effectively compensate high nonlinearity of a sextuple multiplier operating at 99.6GHz. An 18.9dB adjacent-channel power ratio (ACPR) improvement is guaranteed and a W-band fiber-wireless system is experimentally investigated....

  6. Comparison of Stationarity Regions for Wireless Channels From 2 GHz to 30 GHz

    DEFF Research Database (Denmark)

    Yi, Tan; Wang, Chengxiang; Nielsen, Jesper Ødum

    2017-01-01

    Millimeter wave (mmWave) communication works in the frequencies above 6 gigahertz (GHz), with the system bandwidth up to 500 megahertz (MHz) or wider. In this case, the channel situations are dramatically different from the existing wireless channels in Third Generation/Fourth Generation (3G/4G...

  7. The DIII-D 3 MW, 110 GHz ECH System

    International Nuclear Information System (INIS)

    Callis, R.W.; Lohr, J.; Ponce, D.; O'Neill, R.C.; Prater, R.; Luce, T.C.

    1999-01-01

    Three 110 GHz gyrotrons with nominal output power of 1 MW each have been installed and are operational on the DIII-D tokamak. One gyrotron is built by Gycom and has a nominal rating of 1 MW and a 2 s pulse length, with the pulse length being determined by the maximum temperature allowed on the edge cooled Boron Nitride window. The second and third gyrotrons were built by Communications and Power Industries (CPI). The first CPI gyrotron uses a double disc FC-75 cooled sapphire window which has a pulse length rating of 0.8 s at 1 MW, 2s at 0.5 MW and 10s at 0.35 MW. The second CPI gyrotron, utilizes a single disc chemical-vapor-deposition diamond window, that employs water cooling around the edge of the disc. Calculation predict that the diamond window should be capable of full 1 MW cw operation. All gyrotrons are connected to the tokamak by a low-loss-windowless evacuated transmission line using circular corrugated waveguide for propagation in the HEl 1 mode. Each waveguide system incorporates a two mirror launcher which can steer the rf beam poloidally from the center to the outer edge of the plasma. Central current drive experiments with the two gyrotrons with 1.5 MW of injected power drove about 0.17 MA. Results from using the three gyrotron systems will be reported as well as the plans to upgrade the system to 6 MW

  8. Comparative study of the luminescence of structures with Ge nanocrystals formed by dry and wet oxidation of SiGe films

    International Nuclear Information System (INIS)

    RodrIguez, A; Ortiz, M I; Sangrador, J; RodrIguez, T; Avella, M; Prieto, A C; Torres, A; Jimenez, J; Kling, A; Ballesteros, C

    2007-01-01

    The luminescence emission of structures containing Ge nanocrystals embedded in a dielectric matrix obtained by dry and wet oxidation of polycrystalline SiGe layers has been studied as a function of the oxidation time and initial SiGe layer thickness. A clear relationship between the intensity of the luminescence, the structure of the sample, the formation of Ge nanocrystals and the oxidation process parameters that allows us to select the appropriate process conditions to get the most efficient emission has been established. The evolution of the composition and thickness of the growing oxides and the remaining SiGe layer during the oxidation processes has been characterized using Raman spectroscopy, x-ray diffraction, Fourier-transform infrared spectroscopy, Rutherford backscattering spectrometry and transmission electron microscopy. For dry oxidation, the luminescence appears suddenly, regardless of the initial SiGe layer thickness, when all the Si of the SiGe has been oxidized and the remaining layer of the segregated Ge starts to be oxidized forming Ge nanocrystals. Luminescence is observed as long as Ge nanocrystals are present. For wet oxidation, the luminescence appears from the first stages of the oxidation, and is related to the formation of Ge-rich nanoclusters trapped in the mixed (Si and Ge) growing oxide. A sharp increase of the luminescence intensity for long oxidation times is also observed, due to the formation of Ge nanocrystals by the oxidation of the layer of segregated Ge. For both processes the luminescence is quenched when the oxidation time is long enough to cause the full oxidation of the Ge nanocrystals. The intensity of the luminescence in the dry oxidized samples is about ten times higher than in the wet oxidized ones for equal initial thickness of the SiGe layer

  9. Chirped Pulse Spectrometer Operating at 200 GHz

    Science.gov (United States)

    Hindle, Francis; Bray, Cédric; Hickson, Kevin; Fontanari, Daniele; Mouelhi, Meriem; Cuisset, Arnaud; Mouret, Gaël; Bocquet, Robin

    2018-01-01

    The combination of electronic sources operating at high frequencies and modern microwave instrumentation has enabled the recent development of chirped pulse spectrometers for the millimetre and THz bands. This type of instrument can operate at high resolution which is particularly suited to gas-phase rotational spectroscopy. The construction of a chirped pulse spectrometer operating at 200 GHz is described in detail while attention is paid to the phase stability and the data accumulation over many cycles. Validation using carbonyl sulphide has allowed the detection limit of the instrument to be established as function of the accumulation. A large number of OCS transitions were identified using a 10-GHz chirped pulse and include the six most abundant isotopologues, the weakest line corresponding to the fundamental R(17) transition of 16O13C33S with a line strength of 4.3 × 10-26 cm-1/(molecule cm-2). The linearity of the system response for different degrees of data accumulation and transition line strength was confirmed over four orders of magnitudes. A simple analysis of the time-domain data was demonstrated to provide the line-broadening coefficient without the need for conversion by a Fourier transform. Finally, the pulse duration is discussed and optimal values are given for both Doppler-limited and collisional regimes.

  10. KEY COMPARISON: CCEM.RF-K9: International comparison of thermal noise standards between 12.4 GHz and 18 GHz (GT-RF/99-1)

    Science.gov (United States)

    Allal, Djamel; Achkar, Joseph

    2006-01-01

    An international comparison of thermal noise-power measurements has been carried out among five national metrology institutes between 12.4 GHz and 18 GHz. Four transfer standards were measured. The following national institutes participated: BNM-LCIE (France), NPL (United Kingdom), PTB (Germany), NIST (United States of America) and VNIIFTRI (Russia). The Bureau National de Métrologie-Laboratoire Central des Industries Electriques (France) acted as the pilot laboratory for the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  11. 10C survey of radio sources at 15.7 GHz - II. First results

    Science.gov (United States)

    AMI Consortium; Davies, Mathhew L.; Franzen, Thomas M. O.; Waldram, Elizabeth M.; Grainge, Keith J. B.; Hobson, Michael P.; Hurley-Walker, Natasha; Lasenby, Anthony; Olamaie, Malak; Pooley, Guy G.; Riley, Julia M.; Rodríguez-Gonzálvez, Carmen; Saunders, Richard D. E.; Scaife, Anna M. M.; Schammel, Michel P.; Scott, Paul F.; Shimwell, Timothy W.; Titterington, David J.; Zwart, Jonathan T. L.

    2011-08-01

    In a previous paper (Paper I), the observational, mapping and source-extraction techniques used for the Tenth Cambridge (10C) Survey of Radio Sources were described. Here, the first results from the survey, carried out using the Arcminute Microkelvin Imager Large Array (LA) at an observing frequency of 15.7 GHz, are presented. The survey fields cover an area of ≈27 deg2 to a flux-density completeness of 1 mJy. Results for some deeper areas, covering ≈12 deg2, wholly contained within the total areas and complete to 0.5 mJy, are also presented. The completeness for both areas is estimated to be at least 93 per cent. The 10C survey is the deepest radio survey of any significant extent (≳0.2 deg2) above 1.4 GHz. The 10C source catalogue contains 1897 entries and is available online. The source catalogue has been combined with that of the Ninth Cambridge Survey to calculate the 15.7-GHz source counts. A broken power law is found to provide a good parametrization of the differential count between 0.5 mJy and 1 Jy. The measured source count has been compared with that predicted by de Zotti et al. - the model is found to display good agreement with the data at the highest flux densities. However, over the entire flux-density range of the measured count (0.5 mJy to 1 Jy), the model is found to underpredict the integrated count by ≈30 per cent. Entries from the source catalogue have been matched with those contained in the catalogues of the NRAO VLA Sky Survey and the Faint Images of the Radio Sky at Twenty-cm survey (both of which have observing frequencies of 1.4 GHz). This matching provides evidence for a shift in the typical 1.4-GHz spectral index to 15.7-GHz spectral index of the 15.7-GHz-selected source population with decreasing flux density towards sub-mJy levels - the spectra tend to become less steep. Automated methods for detecting extended sources, developed in Paper I, have been applied to the data; ≈5 per cent of the sources are found to be extended

  12. NASA developments in solid state power amplifiers

    Science.gov (United States)

    Leonard, Regis F.

    1990-01-01

    Over the last ten years, NASA has undertaken an extensive program aimed at development of solid state power amplifiers for space applications. Historically, the program may be divided into three phases. The first efforts were carried out in support of the advanced communications technology satellite (ACTS) program, which is developing an experimental version of a Ka-band commercial communications system. These first amplifiers attempted to use hybrid technology. The second phase was still targeted at ACTS frequencies, but concentrated on monolithic implementations, while the current, third phase, is a monolithic effort that focusses on frequencies appropriate for other NASA programs and stresses amplifier efficiency. The topics covered include: (1) 20 GHz hybrid amplifiers; (2) 20 GHz monolithic MESFET power amplifiers; (3) Texas Instruments' (TI) 20 GHz variable power amplifier; (4) TI 20 GHz high power amplifier; (5) high efficiency monolithic power amplifiers; (6) GHz high efficiency variable power amplifier; (7) TI 32 GHz monolithic power amplifier performance; (8) design goals for Hughes' 32 GHz variable power amplifier; and (9) performance goals for Hughes' pseudomorphic 60 GHz power amplifier.

  13. Performance and operation of advanced superconducting electron cyclotron resonance ion source SECRAL at 24 GHz

    International Nuclear Information System (INIS)

    Zhao, H. W.; Zhang, X. Z.; Feng, Y. C.; Guo, J. W.; Li, J. Y.; Guo, X. H.; Sha, S.; Sun, L. T.; Xie, D. Z.; Lu, W.; Cao, Y.

    2012-01-01

    SECRAL (superconducting ECR ion source with advanced design in Lanzhou) ion source has been in routine operation for Heavy Ion Research Facility in Lanzhou (HIRFL) accelerator complex since May 2007. To further enhance the SECRAL performance in order to satisfy the increasing demand for intensive highly charged ion beams, 3-5 kW high power 24 GHz single frequency and 24 GHz +18 GHz double frequency with an aluminum plasma chamber were tested, and some exciting results were produced with quite a few new record highly charged ion beam intensities, such as 129 Xe 35+ of 64 eμA, 129 Xe 42+ of 3 eμA, 209 Bi 41+ of 50 eμA, 209 Bi 50+ of 4.3 eμA and 209 Bi 54+ of 0.2 eμA. In most cases SECRAL is operated at 18 GHz to deliver highly charged heavy ion beams for the HIRFL accelerator, only for those very high charge states and very heavy ion beams such as 209 Bi 36+ and 209 Bi 41+ , SECRAL has been operated at 24 GHz. The total operation beam time provided by SECRAL up to July 2011 has exceeded 7720 hours. In this paper, the latest performance, development, and operation status of SECRAL ion source are presented. The latest results and reliable long-term operation for the HIRFL accelerator have demonstrated that SECRAL performance for production of highly charged heavy ion beams remains improving at higher RF power with optimized tuning.

  14. GHz-rate optical parametric amplifier in hydrogenated amorphous silicon

    International Nuclear Information System (INIS)

    Wang, Ke-Yao; Foster, Amy C

    2015-01-01

    We demonstrate optical parametric amplification operating at GHz-rates at telecommunications wavelengths using a hydrogenated amorphous silicon waveguide through the nonlinear optical process of four-wave mixing. We investigate how the parametric amplification scales with repetition rate. The ability to achieve amplification at GHz-repetition rates shows hydrogenated amorphous silicon’s potential for telecommunication applications and a GHz-rate optical parametric oscillator. (paper)

  15. Alternative Sigma Factors SigF, SigE, and SigG Are Essential for Sporulation in Clostridium botulinum ATCC 3502

    OpenAIRE

    Kirk, David G.; Zhang, Zhen; Korkeala, Hannu; Lindström, Miia

    2014-01-01

    Clostridium botulinum produces heat-resistant endospores that may germinate and outgrow into neurotoxic cultures in foods. Sporulation is regulated by the transcription factor Spo0A and the alternative sigma factors SigF, SigE, SigG, and SigK in most spore formers studied to date. We constructed mutants of sigF, sigE, and sigG in C. botulinum ATCC 3502 and used quantitative reverse transcriptase PCR and electron microscopy to assess their expression of the sporulation pathway on transcription...

  16. High strain amount in recessed junctions induced by selectively deposited boron-doped SiGe layers

    Energy Technology Data Exchange (ETDEWEB)

    Radamson, H.H. [School of Information and Communication Technology, KTH (Royal Institute of Technology) Isafjordsg. 22-26, Electrum 229, 16640 Kista (Sweden)], E-mail: rad@kth.se; Kolahdouz, M.; Ghandi, R.; Ostling, M. [School of Information and Communication Technology, KTH (Royal Institute of Technology) Isafjordsg. 22-26, Electrum 229, 16640 Kista (Sweden)

    2008-12-05

    This work presents the selective epitaxial growth (SEG) of Si{sub 1-x}Ge{sub x} (x = 0.15-0.315) layers with high amount of boron (1 x 10{sup 20}-1 x 10{sup 21} cm{sup -3}) in recessed or unprocessed (elevated) openings for source/drain applications in CMOS has been studied. The influence of the growth rate and strain on boron incorporation has been studied. A focus has been made on the strain distribution and boron incorporation in SEG of SiGe layers.

  17. High strain amount in recessed junctions induced by selectively deposited boron-doped SiGe layers

    International Nuclear Information System (INIS)

    Radamson, H.H.; Kolahdouz, M.; Ghandi, R.; Ostling, M.

    2008-01-01

    This work presents the selective epitaxial growth (SEG) of Si 1-x Ge x (x = 0.15-0.315) layers with high amount of boron (1 x 10 20 -1 x 10 21 cm -3 ) in recessed or unprocessed (elevated) openings for source/drain applications in CMOS has been studied. The influence of the growth rate and strain on boron incorporation has been studied. A focus has been made on the strain distribution and boron incorporation in SEG of SiGe layers

  18. Experimental results for a 1.5 MW, 110 GHz gyrotron oscillator with reduced mode competition

    Science.gov (United States)

    Choi, E. M.; Marchewka, C. D.; Mastovsky, I.; Sirigiri, J. R.; Shapiro, M. A.; Temkin, R. J.

    2006-02-01

    A new result from a 110GHz gyrotron at MIT is reported with an output power of 1.67MW and an efficiency of 42% when operated at 97kV and 41A for 3μs pulses in the TE22,6 mode. These results are a major improvement over results obtained with an earlier cavity design, which produced 1.43MW of power at 37% efficiency. These new results were obtained using a cavity with a reduced output taper angle and a lower ohmic loss when compared with the earlier cavity. The improved operation is shown experimentally to be the result of reduced mode competition from the nearby TE19,7 mode. The reduced mode competition agrees well with an analysis of the startup scenario based on starting current simulations. The present results should prove useful in planning long pulse and CW versions of the 110GHz gyrotron.

  19. Experimental results for a 1.5 MW, 110 GHz gyrotron oscillator with reduced mode competition

    International Nuclear Information System (INIS)

    Choi, E.M.; Marchewka, C.D.; Mastovsky, I.; Sirigiri, J.R.; Shapiro, M.A.; Temkin, R.J.

    2006-01-01

    A new result from a 110 GHz gyrotron at MIT is reported with an output power of 1.67 MW and an efficiency of 42% when operated at 97 kV and 41 A for 3 μs pulses in the TE 22,6 mode. These results are a major improvement over results obtained with an earlier cavity design, which produced 1.43 MW of power at 37% efficiency. These new results were obtained using a cavity with a reduced output taper angle and a lower ohmic loss when compared with the earlier cavity. The improved operation is shown experimentally to be the result of reduced mode competition from the nearby TE 19,7 mode. The reduced mode competition agrees well with an analysis of the startup scenario based on starting current simulations. The present results should prove useful in planning long pulse and CW versions of the 110 GHz gyrotron

  20. TWT design requirements for 30/20 GHz digital communications' satellite

    Science.gov (United States)

    Stankiewicz, N.; Anzic, G.

    1979-01-01

    The rapid growth of communication traffic (voice, data, and video) requires the development of additional frequency bands before the 1990's. The frequencies currently in use for satellite communications at 6/4 GHz are crowded and demands for 14/12 GHz systems are increasing. Projections are that these bands will be filled to capacity by the late 1980's. The next higher frequency band allocated for satellite communications is at 30/20 GHz. For interrelated reasons of efficiency, power level, and system reliability criteria, a candidate for the downlink amplifier in a 30/20 GHz communications' satellite is a dual mode traveling wave tube (TWT) equipped with a highly efficient depressed collector. A summary is given of the analyses which determine the TWT design requirements. The overall efficiency of such a tube is then inferred from a parametric study and from experimental data on multistaged depressed collectors. The expected TWT efficiency at 4 dB below output saturation is 24 percent in the high mode and 22 percent in the low mode.

  1. Flight, orientation, and homing abilities of honeybees following exposure to 2.45-GHz CW microwaves.

    Science.gov (United States)

    Gary, N E; Westerdahl, B B

    1981-01-01

    Foraging-experienced honeybees retained normal flight, orientation, and memory functions after 30 minutes' exposure to 2.45-GHz CW microwaves at power densities from 3 to 50 mW/cm2. These experiments were conducted at power densities approximating and exceeding those that would be present above receiving antennas of the proposed solar power satellite (SPS) energy transmission system and for a duration exceeding that which honeybees living outside a rectenna might be expected to spend within the rectenna on individual foraging trips. There was no evidence that airborne invertebrates would be significantly affected during transient passage through microwaves associated with SPS ground-based microwave receiving stations.

  2. First 200 kW CW operation of a 60 GHz gyrotron

    International Nuclear Information System (INIS)

    Jory, H.; Bier, R.; Evans, S.; Felch, K.; Fox, L.; Huey, H.; Shively, J.; Spang, S.

    1983-01-01

    The gyrotron is a microwave tube which employs the electron cyclotron maser interaction to produce high power output at millimeter wavelengths. It has important and growing applications for heating of plasmas in controlled thermonuclear fusion experiments. The Varian 60 GHz gyrotron has recently generated microwave power in excess of 200 kW during CW operation, wth excellent dynamic range and operating stability. This is the highest average power ever produced by a microwave tube in the millimeter wave region. A description of the gyrotron design and test results are presented

  3. Thermal-Mechanical Study of 3.9 GHz CW Coupler and Cavity for LCLS-II Project

    Energy Technology Data Exchange (ETDEWEB)

    Gonin, Ivan [Fermilab; Harms, Elvin [Fermilab; Khabiboulline, Timergali [Fermilab; Solyak, Nikolay [Fermilab; Yakovlev, Vyacheslav [Fermilab

    2017-05-01

    Third harmonic system was originally developed by Fermilab for FLASH facility at DESY and then was adopted and modified by INFN for the XFEL project [1-3]. In contrast to XFEL project, all cryomodules in LCLS-II project will operate in CW regime with higher RF average power for 1.3 GHz and 3.9 GHz cavities and couplers. Design of the cavity and fundamental power coupler has been modified to satisfy LCLS-II requirements. In this paper we discuss the results of COMSOL thermal and mechanical analysis of the 3.9 GHz coupler and cavity to verify proposed modifica-tion of the design. For the dressed cavity we present simulations of Lorentz force detuning, helium pressure sensitivity df/dP and major mechanical resonances.

  4. Analysis of a prototype of a novel 1.5 MW, 170 GHz coaxial cavity gyrotron

    International Nuclear Information System (INIS)

    Rzesnicki, T.

    2007-06-01

    A 170 GHz, 2 MW coaxial cavity gyrotron is under development at the Institut fuer Hochleistungsimpuls- und Mikrowellentechnik (IHM) at Forschungszentrum Karlsruhe (FZK) which will be used as a high power microwave source for heating, current drive and stability control of plasmas in the International Thermonuclear Experimental Reactor (ITER). At frequencies above about 100 GHz the output power of conventional gyrotrons with cylindrical hollow waveguide cavities is limited to 1 MW in CW operation mainly due to the high Ohmic losses and the space charge voltage depression of the electron beam. The coaxial geometry enables a reduction of the mode competition in the gyrotron resonator and decreases also the influence of the beam voltage depression. As result a very high order operating mode (for example TE34,19 at 170 GHz) can be chosen which ultimately allows to increase the output power of the gyrotron in CW operation to a value as high as 2 MW. A first prototype of the 170 GHz, 2 MW coaxial cavity gyrotron has been designed, built and experimentally tested in short pulse operation at FZK. The main goal of this work was to investigate experimentally the design of the critical gyrotron components such as electron gun, resonator and a quasi-optical RF system. Those components are same as used in the first industrial coaxial prototype gyrotron for ITER. During the experiments a strong instability was observed inside the gyrotron tube due to the excitation of parasitic low frequency oscillations. The mechanism of the oscillations has been studied and possibilities for their suppression of these oscillations are proposed and experimentally verified. The RF output system is one of the most critical components. It is responsible for the coupling of the gyrotron power out of the gyrotron by converting the microwave power generated in the TE 34,19 -mode into a fundamental free space TEM 0,0 ''Gaussian'' mode. The performance of the RF output system has been tested in low

  5. Millimeter-Wave Receiver Concepts for 77 GHz Automotive Radar in Silicon-Germanium Technology

    CERN Document Server

    Kissinger, Dietmar

    2012-01-01

    The book presents the analysis and design of integrated automotive radar receivers in Silicon-Germanium technology, for use in complex multi-channel radar transceiver front-ends in the 77GHz frequency band. The main emphasis of the work is the realization of high-linearity and low-power modular receiver channels as well as the investigation of millimeter-wave integrated test concepts for the receiver front-end.

  6. Indoor Corridor Wideband Radio Propagation Measurements and Channel Models for 5G Millimeter Wave Wireless Communications at 19 GHz, 28 GHz, and 38 GHz Bands

    Directory of Open Access Journals (Sweden)

    Ahmed M. Al-samman

    2018-01-01

    Full Text Available This paper presents millimeter wave (mmWave measurements in an indoor environment. The high demands for the future applications in the 5G system require more capacity. In the microwave band below 6 GHz, most of the available bands are occupied; hence, the microwave band above 6 GHz and mmWave band can be used for the 5G system to cover the bandwidth required for all 5G applications. In this paper, the propagation characteristics at three different bands above 6 GHz (19, 28, and 38 GHz are investigated in an indoor corridor environment for line of sight (LOS and non-LOS (NLOS scenarios. Five different path loss models are studied for this environment, namely, close-in (CI free space path loss, floating-intercept (FI, frequency attenuation (FA path loss, alpha-beta-gamma (ABG, and close-in free space reference distance with frequency weighting (CIF models. Important statistical properties, such as power delay profile (PDP, root mean square (RMS delay spread, and azimuth angle spread, are obtained and compared for different bands. The results for the path loss model found that the path loss exponent (PLE and line slope values for all models are less than the free space path loss exponent of 2. The RMS delay spread for all bands is low for the LOS scenario, and only the directed path is contributed in some spatial locations. For the NLOS scenario, the angle of arrival (AOA is extensively investigated, and the results indicated that the channel propagation for 5G using high directional antenna should be used in the beamforming technique to receive the signal and collect all multipath components from different angles in a particular mobile location.

  7. Circular waveguide mode converters at 140 GHz

    International Nuclear Information System (INIS)

    Trulsen, J.; Woskoboinikow, P.; Temkin, R.J.

    1986-01-01

    A unified derivation of the coupled mode equations for circular waveguide is presented. Also, approximate design criteria for TE/sub 0n/ to TE/sub 0n'/ axisymmetric, TE 01 to TE 11 wriggle, and TE 01 to TM 11 bend converters are reviewed. Numerically solving the coupled mode equations, an optimized set of mode converters has been designed for conversion of a 2 millimeter wave TE 03 mode into TE 11 . This set consists of axisymmetric TE 03 to TE 02 and TE 02 to TE 01 converters followed by a wriggle TE 01 to TE 11 converter. This mode converter set was fabricated and tested using a 3 kW, 137 GHz gyrotron. A TE 11 mode purity of better than 97% was achieved. The TE 01 to TE 11 wriggle converter was experimentally optimized for a measured conversion efficiency of better than 99% not including ohmic losses

  8. Quantum limited quasiparticle mixers at 100 GHz

    International Nuclear Information System (INIS)

    Mears, C.A; Hu, Qing; Richards, P.L.; Worsham, A.H.; Prober, D.E.; Raeisaenen, A.V.

    1990-09-01

    We have made accurate measurements of the noise and gain of superconducting-insulating-superconducting (SIS) mixers employing small area (1μm 2 ) Ta/Ta 2 O 5 /Pb 0.9 Bi 0.1 tunnel junctions. We have measured an added mixer noise of 0.61 +/- 0.31 quanta at 95.0 GHz, which is within 25 percent of the quantum limit of 0.5 quanta. We have carried out a detailed comparison between theoretical predictions of the quantum theory of mixing and experimentally measured noise and gain. We used the shapes of I-V curves pumped at the upper and lower sideband frequencies to deduce values of the embedding admittances at these frequencies. Using these admittances, the mixer noise and gain predicted by quantum theory are in excellent agreement with experiment. 21 refs., 9 figs

  9. Direct satellite TV - The 12-GHz challenge

    Science.gov (United States)

    Fawcette, J.

    1982-02-01

    Manufacturers in Japan and Europe are developing the hardware necessary for commercially feasible direct broadcast satellite TV, including high-frequency circuits and mini-dishes for spacecasting. US companies are lagging behind due to formidable regulatory and legal difficulties. The article focuses on efforts to develop simple, inexpensive receivers which will be able to convert 12-GHz satellite transmissions into high-quality TV images. Three basic receiver designs are being developed: the mixer-downcaster, microwave integrated circuits using FET-preamplifier front ends with transistors connected by bond-wires, and monolithic gallium arsenide integrated circuits. Several companies are on the verge of introducing commercialized receivers utilizing these different basic designs.

  10. Development of two series ingnitron based crowbar protection system for 42 GHz and 82.6 GHz gyroton in SST-1

    International Nuclear Information System (INIS)

    Dhorajiya, Pragnesh; Dalakoti, Shefali; Patel, Harshida; Ingle, Krunal; Patel, Jatin; Sathyanarayana, K.; Rajanbabu; Shukla, B.K.

    2013-01-01

    Gyrotrons are used to generate the high power at microwave frequency that is used to heat the plasma inside a Tokamak. A conventional high voltage power supply is used for the testing of 82.6 GHz, 200 kW/CW and 42 GHz, 500 kW/500ms gyrotrons at our institute. Its maximum operating cathode parameters are -55 kV DC, 20 A. Like any other High RF power tubes gyrotrons need to be protected against arc faults within the tube. If the energy dumped in such arc fault is more than the critical crater energy of the tube, irreparable damage can occur inside the RF tube or microwave tube and rendering it useless. The specified maximum fault energy for the 42 GHz and 82.6 GHz gyrotrons is 10 joules. When conventional HVDC power supplies feed high power RF tubes or microwave tubes, a reliable crowbar protection is required which is tested separately to limit the energy to the tube in case of any type of fault to assure the tube safety. Two series ignitron (NL-37248) based crowbar system developed in-house is used to limit the arc fault energy under the acceptance level by diverting the fault current from the load or Gyrotron. Fault current diversion and interruption are initiated by the sensing element and protection system. The required protection cards are designed and developed in-house and required performance is achieved. With this crowbar system the high voltage switch-off to the gyrotron is achieved within 5 μsec after occurrence of critical faults. The crowbar is tested for voltage hold-off up to 80 kV DC. This paper presents the critical requirement of the time delay for the fault sensing and crowbar trigger generation and necessary protections that are incorporated with the ignitron switch crowbar like over voltage, pulsed over current and continuous over current. The crowbar system developed in-house, tested at rated value. The results obtained during the stand-alone tests and commissioning tests are also mentioned. Using this crowbar system the high voltage power

  11. Development of Low-Noise Small-Area 24 GHz CMOS Radar Sensor

    Directory of Open Access Journals (Sweden)

    Min Yoon

    2016-01-01

    Full Text Available We present a low-noise small-area 24 GHz CMOS radar sensor for automotive collision avoidance. This sensor is based on direct-conversion pulsed-radar architecture. The proposed circuit is implemented using TSMC 0.13 μm RF (radio frequency CMOS (fT/fmax=120/140 GHz technology, and it is powered by a 1.5 V supply. This circuit uses transmission lines to reduce total chip size instead of real bulky inductors for input and output impedance matching. The layout techniques for RF are used to reduce parasitic capacitance at the band of 24 GHz. The proposed sensor has low cost and low power dissipation since it is realized using CMOS process. The proposed sensor showed the lowest noise figure of 2.9 dB and the highest conversion gain of 40.2 dB as compared to recently reported research results. It also showed small chip size of 0.56 mm2, low power dissipation of 39.5 mW, and wide operating temperature range of −40 to +125°C.

  12. TFTR 60 GHz alpha particle collective Thomson Scattering diagnostic

    International Nuclear Information System (INIS)

    Machuzak, J.S.; Woskov, P.P.; Gilmore, J.; Bretz, N.L.; Park, H.K.; Bindslev, H.

    1995-03-01

    A 60 GHz gyrotron collective Thomson Scattering alpha particle diagnostic has been implemented for the D-T period on TFM. Gyrotron power of 0.1-1 kW in pulses of up to 1 second can be launched in X-mode. Efficient corrugated waveguides are used with antennaes and vacuum windows of the TFTR Microwave Scattering system. A multichannel synchronous detector receiver system and spectrum analyzer acquire the scattered signals. A 200 Megasample/sec digitizer is used to resolve fine structure in the frequency spectrum. By scattering nearly perpendicular to the magnetic field, this experiment will take advantage of an enhancement of the scattered signal which results from the interaction of the alpha particles with plasma resonances in the lower hybrid frequency range. Significant enhancements are expected, which will make these measurements possible with gyrotron power less than 1 kW, while maintaining an acceptable signal to noise ratio. We hope to extract alpha particle density and velocity distribution functions from the data. The D and T fuel densities and temperatures may also be obtainable by measurement of the respective ion cyclotron harmonic frequencies

  13. Power

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård; Fogsgaard, Morten

    2016-01-01

    and creativity suggests that when managers give people the opportunity to gain power and explicate that there is reason to be more creative, people will show a boost in creative behaviour. Moreover, this process works best in unstable power hierarchies, which implies that power is treated as a negotiable....... It is thus a central point that power is not necessarily something that breaks down and represses. On the contrary, an explicit focus on the dynamics of power in relation to creativity can be productive for the organisation. Our main focus is to elaborate the implications of this for practice and theory...

  14. Band structure of Si/Ge core-shell nanowires along the [110] direction modulated by external uniaxial strain

    International Nuclear Information System (INIS)

    Peng Xihong; Tang Fu; Logan, Paul

    2011-01-01

    Strain modulated electronic properties of Si/Ge core-shell nanowires along the [110] direction were reported, on the basis of first principles density-functional theory calculations. In particular, the energy dispersion relationship of the conduction/valence band was explored in detail. At the Γ point, the energy levels of both bands are significantly altered by applied uniaxial strain, which results in an evident change of the band gap. In contrast, for the K vectors far away from Γ, the variation of the conduction/valence band with strain is much reduced. In addition, with a sufficient tensile strain (∼1%), the valence band edge shifts away from Γ, which indicates that the band gap of the Si/Ge core-shell nanowires experiences a transition from direct to indirect. Our studies further showed that effective masses of charge carriers can also be tuned using the external uniaxial strain. The effective mass of the hole increases dramatically with tensile strain, while strain shows a minimal effect on tuning the effective mass of the electron. Finally, the relation between strain and the conduction/valence band edge is discussed thoroughly in terms of site-projected wavefunction characters.

  15. Handoff Management in Radio over Fiber 60 GHz Indoor Networks

    NARCIS (Netherlands)

    Bien, V.Q.

    2014-01-01

    Because of high data rate multimedia applications such as HD and UHDTV, online games, etc., the future home networks are expected to support short-range gigabit transmission. With the worldwide availability of 5 GHz spectrum at the 60 GHz band, it creates the opportunity for a promising air

  16. Towards low-cost gigabit wireless systems at 60 GHz

    NARCIS (Netherlands)

    Yang, Haibing

    2008-01-01

    The world-wide availability of the huge amount of license-free spectral space in the 60 GHz band provides wide room for gigabit-per-second (Gb/s) wireless applications. A commercial (read: low-cost) 60-GHz transceiver will, however, provide limited system performance due to the stringent link budget

  17. The 1.4 GHZ light curve of GRB 970508

    NARCIS (Netherlands)

    Galama, TJ; Wijers, RAMJ; Groot, PJ; Strom, RG; De Bruyn, AG; Kouveliotou, C; Robinson, CR; van Paradus, J

    1998-01-01

    We report on Westerbork 1.4 GHz radio observations of the radio counterpart to gamma-ray burst GRB 970508, between 0.80 and 138 days after this event. The 1.4 GHz light curve shows a transition from optically thick to thin emission between 39 and 54 days after the event. We derive the slope p of the

  18. 60 Gbit/s 400 GHz Wireless Transmission

    DEFF Research Database (Denmark)

    Yu, Xianbin; Asif, Rameez; Piels, Molly

    2015-01-01

    We experimentally demonstrate a 400 GHz carrier wireless transmission system with real-time capable detection and demonstrate transmission of a 60 Gbit/s signal derived from optical Nyquist channels in a 12.5 GHz ultra-dense wavelength division multiplexing (UD-WDM) grid and carrying QPSK...

  19. Self-Passivation by Fluorine Plasma Treatment and Low-Temperature Annealing in SiGe Nano wires for Biochemical Sensors

    International Nuclear Information System (INIS)

    Chang, K.; Chen, C.; Kuo, P.; Chen, Y.; Chang, T.; Lai, C.; Whang, A. J.; Lai, Y.; Chen, H.; Hsieh, I.

    2014-01-01

    Nano wires are widely used as highly sensitive sensors for electrical detection of biological and chemical species. Modifying the band structure of strained-Si metal-oxide-semiconductor field-effect transistors by applying the in-plane tensile strain reportedly improves electron and hole mobility. The oxidation-induced Ge condensation increases the Ge fraction in a SiGe-on-insulator (SGOI) and substantially increases hole mobility. However, oxidation increases the number of surface states, resulting in hole mobility degradation. In this work, 3-aminopropyltrimethoxysilane (APTMS) was used as a biochemical reagent. The hydroxyl molecule on the oxide surface was replaced by the methoxy groups of the APTMS molecule. We proposed a surface plasma treatment to improve the electrical properties of SiGe nano wires. Fluorine plasma treatment can result in enhanced rates of thermal oxidation and speed up the formation of a self-passivation oxide layer. Like a capping oxide layer, the self-passivation oxide layer reduces the rate of follow-up oxidation. Pre oxidation treatment also improved the sensitivity of SiGe nano wires because the Si-F binding was held at a more stable interface state compared to bare nano wire on the SiGe surface. Additionally, the sensitivity can be further improved by either the N 2 plasma posttreatment or the low-temperature post annealing due to the suppression of out diffusion of Ge and F atoms from the SiGe nano wire surface.

  20. Measurement of low-frequency base and collector current noise and coherence in SiGe heterojunction bipolar transistors using transimpedance amplifiers

    NARCIS (Netherlands)

    Bruce, S.P.O.; Vandamme, L.K.J.; Rydberg, A.

    1999-01-01

    Transimpedance amplifiers have been used for direct study of current noise in silicon germanium (SiGe) heterojunction bipolar transistors (HBT's) at different biasing conditions. This has facilitated a wider range of resistances in the measurement circuit around the transistor than is possible when

  1. A New 95 GHz Methanol Maser Catalog. I. Data

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Wenjin; Xu, Ye; Lu, Dengrong; Ju, Binggang; Li, Yingjie [Purple Mountain Observatory, Chinese Academy of Science, Nanjing 210008 (China); Chen, Xi [Center for Astrophysics, GuangZhou University, Guangzhou 510006 (China); Ellingsen, Simon P., E-mail: wjyang@pmo.ac.cn, E-mail: xuye@pmo.ac.cn, E-mail: chenxi@shao.ac.cn [School of Physical Sciences, University of Tasmania, Hobart, Tasmania (Australia)

    2017-08-01

    The Purple Mountain Observatory 13.7 m radio telescope has been used to search for 95 GHz (8{sub 0}–7{sub 1}A{sup +}) class I methanol masers toward 1020 Bolocam Galactic Plane Survey (BGPS) sources, leading to 213 detections. We have compared the line width of the methanol and HCO{sup +} thermal emission in all of the methanol detections, and on that basis, we find that 205 of the 213 detections are very likely to be masers. This corresponds to an overall detection rate of 95 GHz methanol masers toward our BGPS sample of 20%. Of the 205 detected masers, 144 (70%) are new discoveries. Combining our results with those of previous 95 GHz methanol maser searches, a total of 481 95 GHz methanol masers are now known. We have compiled a catalog listing the locations and properties of all known 95 GHz methanol masers.

  2. Low noise 874 GHz receivers for the International Submillimetre Airborne Radiometer (ISMAR)

    Science.gov (United States)

    Hammar, A.; Sobis, P.; Drakinskiy, V.; Emrich, A.; Wadefalk, N.; Schleeh, J.; Stake, J.

    2018-05-01

    We report on the development of two 874 GHz receiver channels with orthogonal polarizations for the International Submillimetre Airborne Radiometer. A spline horn antenna and dielectric lens, a Schottky diode mixer circuit, and an intermediate frequency (IF) low noise amplifier circuit were integrated in the same metallic split block housing. This resulted in a receiver mean double sideband (DSB) noise temperature of 3300 K (minimum 2770 K, maximum 3400 K), achieved at an operation temperature of 40 °C and across a 10 GHz wide IF band. A minimum DSB noise temperature of 2260 K at 20 °C was measured without the lens. Three different dielectric lens materials were tested and compared with respect to the radiation pattern and noise temperature. All three lenses were compliant in terms of radiation pattern, but one of the materials led to a reduction in noise temperature of approximately 200 K compared to the others. The loss in this lens was estimated to be 0.42 dB. The local oscillator chains have a power consumption of 24 W and consist of custom-designed Schottky diode quadruplers (5% power efficiency in operation, 8%-9% peak), commercial heterostructure barrier varactor (HBV) triplers, and power amplifiers that are pumped by using a common dielectric resonator oscillator at 36.43 GHz. Measurements of the radiation pattern showed a symmetric main beam lobe with full width half maximum <5° and side lobe levels below -20 dB. Return loss of a prototype of the spline horn and lens was measured using a network analyzer and frequency extenders to 750-1100 GHz. Time-domain analysis of the reflection coefficients shows that the reflections are below -25 dB and are dominated by the external waveguide interface.

  3. An RF energy harvester with supply manangement for co-integration into a 2.4 GHz transceiver

    NARCIS (Netherlands)

    Masuch, J.; Delgado-Restituto, M.; Milosevic, D.; Baltus, P.G.M.

    2012-01-01

    This paper presents an RF energy harvester embedded in a low-power transceiver (TRX) front-end. Both the harvester and the TRX use the same antenna and operate at the same frequency of 2.4 GHz using a new topology with a start-up rectifier and exploiting the nonlinear impedance of the RF-DC

  4. Spectrum response and analysis of 77 GHz band collective Thomson scattering diagnostic for bulk and fast ions in LHD plasmas

    DEFF Research Database (Denmark)

    Nishiura, M.; Kubo, S.; Tanaka, K.

    2014-01-01

    A collective Thomson scattering (CTS) diagnostic was developed and used to measure the bulk and fast ions originating from 180 keV neutral beams in the Large Helical Device (LHD). Electromagnetic waves from a gyrotron at 77 GHz with 1 MW power output function as both the probe and electron cyclot...

  5. Performance of 3.9 GHz SRF cavities at Fermilab's ILCTA_MDB nhorizontal test stand

    Energy Technology Data Exchange (ETDEWEB)

    Harms, Elvin; Hocker, Andy; /Fermilab

    2008-08-01

    Fermilab is building a cryomodule containing four 3.9 GHz superconducting radio frequency (SRF) cavities for the Free electron LASer in Hamburg (FLASH) facility at the Deutsches Elektronen-SYnchrotron (DESY) laboratory. Before assembling the cavities into the cryomodule, each individual cavity is tested at Fermilab's Horizontal Test Stand (HTS). The HTS provides the capability to test fully-dressed SRF cavities at 1.8 K with high-power pulsed RF in order to verify that the cavities achieve performance requirements under these conditions. The performance at the HTS of the 3.9 GHz cavities built for FLASH is presented here.

  6. Towards a 1 MW, 170 GHz gyrotron design for fusion application

    Science.gov (United States)

    Kumar, Anil; Kumar, Nitin; Singh, Udaybir; Bhattacharya, Ranajoy; Yadav, Vivek; Sinha, A. K.

    2013-03-01

    The electrical design of different components of 1 MW, 170 GHz gyrotron such as, magnetron injection gun, cylindrical interaction cavity and collector and RF window is presented in this article. Recently, a new project related to the development of 170 GHz, 1 MW gyrotron has been started for the Indian Tokamak. TE34,10 mode is selected as the operating mode after studied the problem of mode competition. The triode type geometry is selected for the design of magnetron injection gun (MIG) to achieve the required beam parameters. The maximum transverse velocity spread of 3.28% at the velocity ratio of 1.34 is obtained in simulations for a 40 A, 80 kV electron beam. The RF output power of more than 1 MW with 36.5% interaction efficiency without depressed collector is predicted by simulation in single-mode operation at 170 GHz frequency. The simulated single-stage depressed collector of the gyrotron predicted the overall device efficiencies >55%. Due to the very good thermal conductivity and very weak dependency of the dielectric parameters on temperature, PACVD diamond is selected for window design for the transmission of RF power. The in-house developed code MIGSYN and GCOMS are used for initial geometry design of MIG and mode selection respectively. Commercially available simulation tools MAGIC and ANSYS are used for beam-wave interaction and mechanical analysis respectively.

  7. CONDOR simulation of an 11.4-GHz traveling wave output cavity

    International Nuclear Information System (INIS)

    Goren, Y.; Yu, D.

    1991-01-01

    The CONDOR code is used to simulate the cold test and the beam-induced microwave amplification of an 11.4-GHz, six-cell, disk-loaded, traveling wave cavity. Cold test simulation results are in agreement with a modified Slater's theory. Power extraction at the output port is calculated by launching a train of Gaussian electron bunches through the structure. Results are consistent with recent relativistic klystron experiments using a similar TW output cavity. It is further shown that, depending on operating beam parameters, the power extraction efficiency can be maximized by modification of various cells in the TW structure

  8. Results on the interaction of an intense bunched electron beam with resonant cavities at 35 GHz

    CERN Document Server

    Gardelle, J; Rullier, J L; Vermare, C; Wuensch, Walter; Lidia, S M; Westenskow, G A; Donohue, J T; Meurdesoif, Y; Lekston, J M; MacKay, W W

    1999-01-01

    The Two-Beam Accelerator (TBA) concept is currently being investigated both at Lawrence Berkeley National Laboratory (LBNL) and at CERN. As part of this program, a 7 MeV, 1-kA electron beam produced by the PIVAIR accelerator at CESTA has been used to power a free electron laser (FEL) amplifier at 35 GHz. At the FEL exit, the bunched electron beam is transported and focused into a resonant cavity built by the CLIC group at CERN. The power and frequency of the microwave output generated when the bunched beam traverses two different cavities are measured. (7 refs).

  9. RF Behavior of Cylindrical Cavity Based 240 GHz, 1 MW Gyrotron for Future Tokamak System

    Science.gov (United States)

    Kumar, Nitin; Singh, Udaybir; Bera, Anirban; Sinha, A. K.

    2017-11-01

    In this paper, we present the RF behavior of conventional cylindrical interaction cavity for 240 GHz, 1 MW gyrotron for futuristic plasma fusion reactors. Very high-order TE mode is searched for this gyrotron to minimize the Ohmic wall loading at the interaction cavity. The mode selection process is carried out rigorously to analyze the mode competition and design feasibility. The cold cavity analysis and beam-wave interaction computation are carried out to finalize the cavity design. The detail parametric analyses for interaction cavity are performed in terms of mode stability, interaction efficiency and frequency. In addition, the design of triode type magnetron injection gun is also discussed. The electron beam parameters such as velocity ratio and velocity spread are optimized as per the requirement at interaction cavity. The design studies presented here confirm the realization of CW, 1 MW power at 240 GHz frequency at TE46,17 mode.

  10. 11-GHz waveguide Nd:YAG laser CW mode-locked with single-layer graphene.

    Science.gov (United States)

    Okhrimchuk, Andrey G; Obraztsov, Petr A

    2015-06-08

    We report stable, passive, continuous-wave (CW) mode-locking of a compact diode-pumped waveguide Nd:YAG laser with a single-layer graphene saturable absorber. The depressed cladding waveguide in the Nd:YAG crystal is fabricated with an ultrafast laser inscription method. The saturable absorber is formed by direct deposition of CVD single-layer graphene on the output coupler. The few millimeter-long cavity provides generation of 16-ps pulses with repetition rates in the GHz range (up to 11.3 GHz) and 12 mW average power. Stable CW mode-locking operation is achieved by controlling the group delay dispersion in the laser cavity with a Gires-Tournois interferometer.

  11. A 12 GHz wavelength spacing multi-wavelength laser source for wireless communication systems

    Science.gov (United States)

    Peng, P. C.; Shiu, R. K.; Bitew, M. A.; Chang, T. L.; Lai, C. H.; Junior, J. I.

    2017-08-01

    This paper presents a multi-wavelength laser source with 12 GHz wavelength spacing based on a single distributed feedback laser. A light wave generated from the distributed feedback laser is fed into a frequency shifter loop consisting of 50:50 coupler, dual-parallel Mach-Zehnder modulator, optical amplifier, optical filter, and polarization controller. The frequency of the input wavelength is shifted and then re-injected into the frequency shifter loop. By re-injecting the shifted wavelengths multiple times, we have generated 84 optical carriers with 12 GHz wavelength spacing and stable output power. For each channel, two wavelengths are modulated by a wireless data using the phase modulator and transmitted through a 25 km single mode fiber. In contrast to previously developed schemes, the proposed laser source does not incur DC bias drift problem. Moreover, it is a good candidate for radio-over-fiber systems to support multiple users using a single distributed feedback laser.

  12. Development of steady-state 2 MW, 170 GHz gyrotrons for ITER

    International Nuclear Information System (INIS)

    Piosczyk, B.; Arnold, A.; Thumm, M.; Dammertz, G.; Heidinger, R.; Illy, S.; Jin, J.; Koppenburg, K.; Leonhardt, W.; Neffe, G.; Rzesnicki, T.; Schmid, M.; Yang, X.; Alberti, S.; Chavan, R.; Fasel, D.; Goodman, T.; Henderson, M.; Hogge, J.P.; Tran, M.Q.; Yovchev, I.; Erckmann, V.; Laqua, H.P.; Michel, G.; Gantenbein, G.; Kasparek, W.; Mueller, G.; Schwoerer, K.; Bariou, D.; Beunas, A.; Giguet, E.; LeCloarec, G.; Legrand, F.; Lievin, C.; Dumbrajs, O.

    2005-01-01

    A prototype of a 1 MW, CW, 140 GHz conventional gyrotron for the W7-X stellarator in Greifswald/Germany has been tested successfully and the fabrication of series tubes started. In extended studies the feasibility for manufacturing a continuously operated high power coaxial cavity gyrotron has been demonstrated and all needed data for an industrial design has been obtained. Based on this results the fabrication of a first prototype of a 2 MW, CW, 170 GHz coaxial cavity gyrotron started recently in cooperation between European research institutions and European tube industry. The prototype tube is foreseen to be tested in 2006 at CRPP Lausanne where a suitable test facility is under construction. (author)

  13. Measurements of the cosmic microwave background temperature at 1.47 GHz

    Science.gov (United States)

    Bensadoun, M.; Bersanelli, M.; De Amici, G.; Kogut, A.; Levin, S. M.; Limon, M.; Smoot, G. F.; Witebsky, C.

    1993-01-01

    We have used a radio-frequency-gain total-power radiometer to measure the intensity of the cosmic microwave background (CMB) at a frequency of 1.47 GHz (20.4 cm wavelength) from White Mountain, California in 1988 September and from the South Pole in 1989 December. The CMB thermodynamic temperature, T(CMB), is 2.27 +/- 0.25 K (68 percent confidence limit) measured from White Mountain and 2.26 +/- 0.20 K from the South Pole site. The combined result is 2.26 +/- 0.19 K. The correction for Galactic emission has been derived from scaled low-frequency maps and constitutes the main source of error. The atmospheric signal is extrapolated from our zenith scan measurements at higher frequencies. These results are consistent with our previous measurement at 1.41 GHz and about 2.5 sigma from the 2.74 +/- 0.01 K global average CMB temperature.

  14. Design of a Wideband 900 GHz Balanced Frequency Tripler for Radioastronomy

    Science.gov (United States)

    Tripon-Canseliet, Charlotte; Maestrini, Alain; Mehdi, Imran

    2004-01-01

    We report on the design of a fix-tuned split-block waveguide balanced frequency tripler working nominally at 900GHz. It uses a GaAs Schottky planar diode pair in a balanced configuration. The circuit will be fabricated with JPL membrane technology in order to minimize dielectric loading. The multiplier is bias-less to dramatically ease the mounting and the operating procedure. At room temperature, the expected output power is 50- 130 (micro)W in the band 800-970 GHz when the tripler is pumped with 4mW. By modifying the waveguide input and output matching circuit, the multiplier can be tuned to operate at lower frequencies.

  15. Design and simulation of a ~390 GHz seventh harmonic gyrotron using a large orbit electron beam

    Science.gov (United States)

    Li, Fengping; He, Wenlong; Cross, Adrian W.; Donaldson, Craig R.; Zhang, Liang; Phelps, Alan D. R.; Ronald, Kevin

    2010-04-01

    A ~390 GHz harmonic gyrotron based on a cusp electron gun has been designed and numerically modelled. The gyrotron operates at the seventh harmonic of the electron cyclotron frequency with the beam interacting with a TE71 waveguide mode. Theoretical as well as numerical simulation results using the 3D particle-in-cell code MAGIC are presented. The cusp gun generated an axis-encircling, annular shaped electron beam of energy 40 keV, current 1.5 A with a velocity ratio α of 3. Smooth cylindrical waveguides have been studied as the interaction cavities and their cavity Q optimized for 390 GHz operation. In the simulations ~600 W of output power at the design frequency has been demonstrated.

  16. Operational upgrades to the DIII-D 60 GHz electron cyclotron resonant heating system

    International Nuclear Information System (INIS)

    Harris, T.E.; Cary, W.P.

    1993-10-01

    One of the primary components of the DIII-D radio frequency (rf) program over the past seven years has been the 60 GHz electron cyclotron resonant heating (ECRH) system. The system now consists of eight units capable of operating and controlling eight Varian VGE-8006 60 GHz, 200 kW gyrotrons along with their associated waveguide components. This paper will discuss the operational upgrades and the overall system performance. Many modifications were instituted to enhance the system operation and performance. Modifications discussed in this paper include an improved gyrotron tube-fault response network, a computer controlled pulse-timing and sequencing system, and an improved high-voltage power supply control interface. The discussion on overall system performance will include operating techniques used to improve system operations and reliability. The techniques discussed apply to system start-up procedures, operating the system in a conditioning mode, and operating the system during DIII-D plasma operations

  17. Development of end group for 1.3 GHZ nine cell SCRF cavity

    International Nuclear Information System (INIS)

    Yedle, Ajay; Bagre, Manish; Maurya, Tilak; Yadav, Anand; Puntambekar, Avinash; Mahawar, Ashish; Mohania, Praveen; Shrivastava, Purushottam; Joshi, Satish Chandra

    2013-01-01

    Raja Ramanna Centre for Advanced Technology (RRCAT) is developing 1.3 GHz superconducting radio frequency (SCRF) cavities as part of SCRF technology development. The 1.3 GHz nine cell SCRF cavities comprise of multiple cells and end groups at each end. These end groups are important parts of a multi-cell cavity. They serve as interface for putting RF power to cavity, pick up the signal for various RF control and have higher order modes (HOM) coupler. The multiple parts with intricate shape, complex weld geometry and stringent RF requirements pose various challenges in their manufacturing. This paper presents the efforts on development of end groups comprising of manufacturing of various parts, their fabrication by electron beam welding process and pre-qualification including mechanical measurement, vacuum leak testing RF measurement. (author)

  18. The 17 GHz active region number

    Energy Technology Data Exchange (ETDEWEB)

    Selhorst, C. L.; Pacini, A. A. [IP and D-Universidade do Vale do Paraíba-UNIVAP, São José dos Campos (Brazil); Costa, J. E. R. [CEA, Instituto Nacional de Pesquisas Espaciais, São José dos Campos (Brazil); Giménez de Castro, C. G.; Valio, A. [CRAAM, Universidade Presbiteriana Mackenzie, São Paulo (Brazil); Shibasaki, K., E-mail: caius@univap.br [Nobeyama Solar Radio Observatory/NAOJ, Minamisaku, Nagano 384-1305 (Japan)

    2014-08-01

    We report the statistics of the number of active regions (NAR) observed at 17 GHz with the Nobeyama Radioheliograph between 1992, near the maximum of cycle 22, and 2013, which also includes the maximum of cycle 24, and we compare with other activity indexes. We find that NAR minima are shorter than those of the sunspot number (SSN) and radio flux at 10.7 cm (F10.7). This shorter NAR minima could reflect the presence of active regions generated by faint magnetic fields or spotless regions, which were a considerable fraction of the counted active regions. The ratio between the solar radio indexes F10.7/NAR shows a similar reduction during the two minima analyzed, which contrasts with the increase of the ratio of both radio indexes in relation to the SSN during the minimum of cycle 23-24. These results indicate that the radio indexes are more sensitive to weaker magnetic fields than those necessary to form sunspots, of the order of 1500 G. The analysis of the monthly averages of the active region brightness temperatures shows that its long-term variation mimics the solar cycle; however, due to the gyro-resonance emission, a great number of intense spikes are observed in the maximum temperature study. The decrease in the number of these spikes is also evident during the current cycle 24, a consequence of the sunspot magnetic field weakening in the last few years.

  19. Whole-body 35-GHz security scanner

    Science.gov (United States)

    Appleby, Roger; Anderton, Rupert N.; Price, Sean; Sinclair, Gordon N.; Coward, Peter R.

    2004-08-01

    A 35GHz imager designed for Security Scanning has been previously demonstrated. That imager was based on a folded conical scan technology and was constructed from low cost materials such as expanded polystyrene and printed circuit board. In conjunction with an illumination chamber it was used to collect indoor imagery of people with weapons and contraband hidden under their clothing. That imager had a spot size of 20mm and covered a field of view of 20 x 10 degrees that partially covered the body of an adult from knees to shoulders. A new variant of this imager has been designed and constructed. It has a field of view of 36 x 18 degrees and is capable of covering the whole body of an adult. This was achieved by increasing the number of direct detection receivers from the 32 used in the previous design to 58, and by implementing an improved optical design. The optics consist of a front grid, a polarisation device which converts linear to circular polarisation and a rotating scanner. This new design uses high-density expanded polystyrene as a correcting element on the back of the front grid. This gives an added degree of freedom that allows the optical design to be diffraction limited over a very wide field of view. Obscuration by the receivers and associated components is minimised by integrating the post detection electronics at the receiver array.

  20. Strategic Control of 60 GHz Millimeter-Wave High-Speed Wireless Links for Distributed Virtual Reality Platforms

    Directory of Open Access Journals (Sweden)

    Joongheon Kim

    2017-01-01

    Full Text Available This paper discusses the stochastic and strategic control of 60 GHz millimeter-wave (mmWave wireless transmission for distributed and mobile virtual reality (VR applications. In VR scenarios, establishing wireless connection between VR data-center (called VR server (VRS and head-mounted VR device (called VRD allows various mobile services. Consequently, utilizing wireless technologies is obviously beneficial in VR applications. In order to transmit massive VR data, the 60 GHz mmWave wireless technology is considered in this research. However, transmitting the maximum amount of data introduces maximum power consumption in transceivers. Therefore, this paper proposes a dynamic/adaptive algorithm that can control the power allocation in the 60 GHz mmWave transceivers. The proposed algorithm dynamically controls the power allocation in order to achieve time-average energy-efficiency for VR data transmission over 60 GHz mmWave channels while preserving queue stabilization. The simulation results show that the proposed algorithm presents desired performance.

  1. Diamond Based DDR IMPATTs: Prospects and Potentiality as Millimeter-Wave Source at 94 GHz Atmospheric Window

    Directory of Open Access Journals (Sweden)

    A. Acharyya

    2013-06-01

    Full Text Available Large-signal simulation is carried out in this paper to investigate the prospects and potentiality of Double-Drift Region (DDR Impact Avalanche Transit Time (IMPATT device based on semiconducting type-IIb diamond as millimeter-wave source operating at 94 GHz atmospheric window frequency. Large-signal simulation method developed by the authors and presented in this paper is based on non-sinusoidal voltage excitation. The simulation is carried out to obtain the large-signal characteristics such as RF power output, DC to RF conversion efficiency etc. of DDR diamond IMPATT device designed to operate at 94 GHz. The results show that the device is capable of delivering a peak RF power output of 7.01 W with 10.18% DC to RF conversion efficiency for a bias current density of 6.0×10^8 A m^-2 and voltage modulation of 60% at 94 GHz; whereas for the same voltage modulation 94 GHz DDR Si IMPATT can deliver only 693.82 mW RF power with 8.74 efficiency for the bias current density of 3.4×10^8 A m^-2.

  2. The 30/20 GHz communications system functional requirements

    Science.gov (United States)

    Siperko, C. M.; Frankfort, M.; Markham, R.; Wall, M.

    1981-01-01

    The characteristics of 30/20 GHz usage in satellite systems to be used in support of projected communication requirements of the 1990's are defined. A requirements analysis which develops projected market demand for satellite services by general and specialized carriers and an analysis of the impact of propagation and system constraints on 30/20 GHz operation are included. A set of technical performance characteristics for the 30/20 GHz systems which can serve the resulting market demand and the experimental program necessary to verify technical and operational aspects of the proposed systems is also discussed.

  3. Packaging of microwave integrated circuits operating beyond 100 GHz

    Science.gov (United States)

    Samoska, L.; Daniel, E.; Sokolov, V.; Sommerfeldt, S.; Bublitz, J.; Olson, K.; Gilbert, B.; Chow, D.

    2002-01-01

    Several methods of packaging high speed (75-330 GHz) InP HEMT MMIC devices are discussed. Coplanar wirebonding is presented with measured insertion loss of less than 0.5dB and return loss better than -17 dB from DC to 110 GHz. A motherboard/daughterboard packaging scheme is presented which supports minimum loss chains of MMICs using this coplanar wirebonding method. Split waveguide block packaging approaches are presented in G-band (140-220 GHz) with two types of MMIC-waveguide transitions: E-plane probe andantipodal finline.

  4. Development of novel low-voltage free-electron lasers in the 5-500GHz region

    International Nuclear Information System (INIS)

    Zhong, Xiehe

    2002-01-01

    The electromagnetic spectrum from 5GHz to 500GHz is important for many industrial, commercial, and scientific applications. In particular for the 100 - 500GHz region, free electron lasers (FELs) are usually the only viable radiation sources with sizeable output power and as such are an attractive enabling technology for many applications. One major issue for widespread application of free electron lasers is to reduce their cost and size. This is particularly challenging because of the expensive electron accelerator system they employ. To make it significantly more attractive economically for many important applications, the electron energy has to be reduced to below 300keV. In this thesis two novel electron-energy-reduction techniques are investigated for FEL systems operated in the spectrum from 5GHz to 500GHz with the development of a suite of suitable FEL codes. In the microwave to millimetre-wave region, a novel energy reduction technique based on second harmonic waveguide FELs is studied. It is shown that the required electron voltage is approximately half of what is normally required for comparable conventional waveguide FELs. Effect of electron energy spread is studied for second harmonic waveguide FELs both in microwave and millimetre-wave regions. It is shown that strong wiggler field enhances electron hunching thereby increasing the small-signal gain as well as the insusceptibility to electron voltage spread. Saturation behaviour of second harmonic waveguide FELs is also studied because it is important for evaluation of output power. For FEL generation above 300GHz, it is found that second harmonic waveguide FELs need to increase electron energy above 300keV. To this end, a second energy reduction technique is considered based on a novel quasiperiodic wiggler. It is established that by changing the initial phase angle between the two component wigglers, strong radiation can be generated near 1THz with electron energy below 300keV. (author)

  5. Efficient Low-Voltage Operation of a CW Gyrotron Oscillator at 233 GHz.

    Science.gov (United States)

    Hornstein, Melissa K; Bajaj, Vikram S; Griffin, Robert G; Temkin, Richard J

    2007-02-01

    The gyrotron oscillator is a source of high average power millimeter-wave through terahertz radiation. In this paper, we report low beam power and high-efficiency operation of a tunable gyrotron oscillator at 233 GHz. The low-voltage operating mode provides a path to further miniaturization of the gyrotron through reduction in the size of the electron gun, power supply, collector, and cooling system, which will benefit industrial and scientific applications requiring portability. Detailed studies of low-voltage operation in the TE(2) (,) (3) (,) (1) mode reveal that the mode can be excited with less than 7 W of beam power at 3.5 kV. During CW operation with 3.5-kV beam voltage and 50-mA beam current, the gyrotron generates 12 W of RF power at 233.2 GHz. The EGUN electron optics code describes the low-voltage operation of the electron gun. Using gun-operating parameters derived from EGUN simulations, we show that a linear theory adequately predicts the low experimental starting currents.

  6. High power klystrons for efficient reliable high power amplifiers

    Science.gov (United States)

    Levin, M.

    1980-11-01

    This report covers the design of reliable high efficiency, high power klystrons which may be used in both existing and proposed troposcatter radio systems. High Power (10 kW) klystron designs were generated in C-band (4.4 GHz to 5.0 GHz), S-band (2.5 GHz to 2.7 GHz), and L-band or UHF frequencies (755 MHz to 985 MHz). The tubes were designed for power supply compatibility and use with a vapor/liquid phase heat exchanger. Four (4) S-band tubes were developed in the course of this program along with two (2) matching focusing solenoids and two (2) heat exchangers. These tubes use five (5) tuners with counters which are attached to the focusing solenoids. A reliability mathematical model of the tube and heat exchanger system was also generated.

  7. Simulation of thermal stress and buckling instability in Si/Ge and Ge/Si core/shell nanowires.

    Science.gov (United States)

    Das, Suvankar; Moitra, Amitava; Bhattacharya, Mishreyee; Dutta, Amlan

    2015-01-01

    The present study employs the method of atomistic simulation to estimate the thermal stress experienced by Si/Ge and Ge/Si, ultrathin, core/shell nanowires with fixed ends. The underlying technique involves the computation of Young's modulus and the linear coefficient of thermal expansion through separate simulations. These two material parameters are combined to obtain the thermal stress on the nanowires. In addition, the thermally induced stress is perceived in the context of buckling instability. The analysis provides a trade-off between the geometrical and operational parameters of the nanostructures. The proposed methodology can be extended to other materials and structures and helps with the prediction of the conditions under which a nanowire-based device might possibly fail due to elastic instability.

  8. Reduction in the formation temperature of Poly-SiGe alloy thin film in Si/Ge system

    Science.gov (United States)

    Tah, Twisha; Singh, Ch. Kishan; Madapu, K. K.; Sarguna, R. M.; Magudapathy, P.; Ilango, S.

    2018-04-01

    The role of deposition temperature in the formation of poly-SiGe alloy thin film in Si/Ge system is reported. For the set ofsamples deposited without any intentional heating, initiation of alloying starts upon post annealingat ˜ 500 °C leading to the formation of a-SiGe. Subsequently, poly-SiGe alloy phase could formonly at temperature ≥ 800 °C. Whereas, for the set of samples deposited at 500 °C, in-situ formation of poly-SiGe alloy thin film could be observed. The energetics of the incoming evaporated atoms and theirsubsequent diffusionsin the presence of the supplied thermal energy is discussed to understand possible reasons for lowering of formation temperature/energyof the poly-SiGe phase.

  9. The enhancement of the interdiffusion in Si/Ge amorphous artificial multilayers by additions of B and Au

    International Nuclear Information System (INIS)

    Park, B.; Spaepen, F.; Poate, J.M.; Jacobson, D.C.

    1990-01-01

    Amorphous Si/amorphous Ge artificial multilayers were prepared by ion beam sputtering. Boron or gold impurities were introduced into the Si/Ge multilayers by ion implantation or during the sputtering deposition. Diffusion coefficients were determined by measuring the decrease in the intensity of the first order X-ray diffraction peak resulting from the composition modulation. It was found that the interdiffusion of Si and Ge in their amorphous phase can be enhanced by doping. The enhancement factor is independent of the degree of structural relaxation, as observed by the decrease of diffusivity with annealing time, of the amorphous phase. A model is proposed that describes this behavior in terms of electronic effects, introduced by the dopants, on the pre-existing structural defects governing diffusion

  10. Improved high-frequency equivalent circuit model based on distributed effects for SiGe HBTs with CBE layout

    International Nuclear Information System (INIS)

    Sun Ya-Bin; Li Xiao-Jin; Zhang Jin-Zhong; Shi Yan-Ling

    2017-01-01

    In this paper, we present an improved high-frequency equivalent circuit for SiGe heterojunction bipolar transistors (HBTs) with a CBE layout, where we consider the distributed effects along the base region. The actual device structure is divided into three parts: a link base region under a spacer oxide, an intrinsic transistor region under the emitter window, and an extrinsic base region. Each region is considered as a two-port network, and is composed of a distributed resistance and capacitance. We solve the admittance parameters by solving the transmission-line equation. Then, we obtain the small-signal equivalent circuit depending on the reasonable approximations. Unlike previous compact models, in our proposed model, we introduce an additional internal base node, and the intrinsic base resistance is shifted into this internal base node, which can theoretically explain the anomalous change in the intrinsic bias-dependent collector resistance in the conventional compact model. (paper)

  11. Silicon transport under rotating and combined magnetic fields in liquid phase diffusion growth of SiGe

    Energy Technology Data Exchange (ETDEWEB)

    Armour, N.; Dost, S. [Crystal Growth Laboratory, University of Victoria, Victoria, BC, V8W 3P6 (Canada)

    2010-04-15

    The effect of applied rotating and combined (rotating and static) magnetic fields on silicon transport during the liquid phase diffusion growth of SiGe was experimentally studied. 72-hour growth periods produced some single crystal sections. Single and polycrystalline sections of the processed samples were examined for silicon composition. Results show that the application of a rotating magnetic field enhances silicon transport in the melt. It also has a slight positive effect on flattening the initial growth interface. For comparison, growth experiments were also conducted under combined (rotating and static) magnetic fields. The processed samples revealed that the addition of static field altered the thermal characteristics of the system significantly and led to a complete melt back of the germanium seed. Silicon transport in the melt was also enhanced under combined fields compared with experiments with no magnetic field. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Effect of a static magnetic field on silicon transport in liquid phase diffusion growth of SiGe

    Energy Technology Data Exchange (ETDEWEB)

    Armour, N.; Dost, S. [Crystal Growth Laboratory, University of Victoria, Victoria, BC V8W 3P6 (Canada)

    2010-03-15

    Liquid phase diffusion experiments have been performed without and with the application of a 0.4 T static magnetic field using a three-zone DC furnace system. SiGe crystals were grown from the germanium side for a period of 72 h. Experiments have led to the growth of single crystal sections varying from 0 to 10 mm thicknesses. Examination of the processed samples (single and polycrystalline sections) has shown that the effect of the applied static magnetic field is significant. It alters the temperature distribution in the system, reduces mass transport in the melt, and leads to a much lower growth rate. The initial curved growth interface was slightly flattened under the effect of magnetic field. There were no growth striations in the single crystal sections of the samples. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Architecture for a 1-GHz Digital RADAR

    Science.gov (United States)

    Mallik, Udayan

    2011-01-01

    An architecture for a Direct RF-digitization Type Digital Mode RADAR was developed at GSFC in 2008. Two variations of a basic architecture were developed for use on RADAR imaging missions using aircraft and spacecraft. Both systems can operate with a pulse repetition rate up to 10 MHz with 8 received RF samples per pulse repetition interval, or at up to 19 kHz with 4K received RF samples per pulse repetition interval. The first design describes a computer architecture for a Continuous Mode RADAR transceiver with a real-time signal processing and display architecture. The architecture can operate at a high pulse repetition rate without interruption for an infinite amount of time. The second design describes a smaller and less costly burst mode RADAR that can transceive high pulse repetition rate RF signals without interruption for up to 37 seconds. The burst-mode RADAR was designed to operate on an off-line signal processing paradigm. The temporal distribution of RF samples acquired and reported to the RADAR processor remains uniform and free of distortion in both proposed architectures. The majority of the RADAR's electronics is implemented in digital CMOS (complementary metal oxide semiconductor), and analog circuits are restricted to signal amplification operations and analog to digital conversion. An implementation of the proposed systems will create a 1-GHz, Direct RF-digitization Type, L-Band Digital RADAR--the highest band achievable for Nyquist Rate, Direct RF-digitization Systems that do not implement an electronic IF downsample stage (after the receiver signal amplification stage), using commercially available off-the-shelf integrated circuits.

  14. Simulating characteristics of Si/Ge tandem monolithic solar cell with Si1-xGex buffer layer

    Directory of Open Access Journals (Sweden)

    Gnilenko A. B.

    2015-12-01

    Full Text Available In spite of many efforts to propose new semiconductor materials and sophisticated constructions of solar cells, crystalline silicone remains the main photovoltaic material widely used up to now. There are various methods to enhance the efficiency of silicone solar cells. One of them is to combine silicone with an additional semiconductor material with the different bandgap to form a tandem construction. For example, the germanium sub-cell used as the bottom cascade for the silicone sub-cell in the tandem monolithic solar cell makes it possible to utilize the "red" sub-band of solar spectra increasing overall solar cell efficiency. The problem of the 4.2% mismatch in lattice constant between Si and Ge can be resolved in such a case by the use of SiGe buffer layer. In the paper the results of the computer simulation for Si/Ge tandem monolithic solar cell with Si1-xGex buffer layer are presented. In the solar cell under consideration, the step graded Si1-xGex buffer layer is located between the top silicone and the bottom germanium cascades to reduce the threading dislocation density in mismatched materials. The cascades are commutated by the use of the germanium tunnel diode between the bottom sub-cell and the buffer layer. For the solar cell modeling, the physically-based device simulator ATLAS of Silvaco TCAD software is employed to predict the electrical behavior of the semiconductor structure and to provide a deep insight into the internal physical processes. The voltage-current characteristic, photovoltaic parameters and the distribution of basic physical values are obtained for the investigated tandem solar cell. The influence of layer thicknesses on the photovoltaic parameters is studied. The calculated efficiency of the tandem solar cell reaches 13% which is a quarter more than the efficiency of a simple silicone solar cell with the same constructive parameters and under the same illumination conditions.

  15. Investigation of high mobility pseudomorphic SiGe p-channels in Si MOSFETS at low and high electric fields

    International Nuclear Information System (INIS)

    Palmer, Martin John

    2001-01-01

    Silicon Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) for high speed, high current applications are rapidly approaching the physical and financial limits of the technology. This opens opportunities for the incorporation of materials with intrinsically better transport characteristics. An alloy of silicon and germanium is one such material that is gaining much recognition as the active component of MOSFETs and as the secondary structures (such as the gate electrode). This work examines a batch of buried channel Si 0.64 Ge 0.36 p-MOSFETs, with a minimum effective length of 0.35 μm, under different bias conditions and at different temperatures. High current and transconductance enhancements are apparent at long gate lengths. The carrier mobility is up to a factor of 2.5 times that of silicon at room temperature and 7.5 times at 4 K. A clear trend of decreasing peak mobility with decreasing silicon cap thickness is evident. Simulations show that scattering caused by the roughness of the SiO 2 /Si interface dominates, rather than alloy scattering or Si/SiGe roughness, even for a buried channel. This scattering increases with the proximity of the carriers to the interface. An increase of interface trap density with decreasing cap thickness, demonstrates that segregated germanium exists some distance into the cap and interferes with the oxidation process. This will increase scattering through increased SiO 2 /Si roughness and increased trapped charge. The short channel, high field results are comparable or slightly worse than those of silicon due to lower saturation drift velocity. However, fitting to a drift-diffusion model shows an apparent increase in saturation velocity for short channels, especially at low temperatures. This effect correlates with the low field mobility and is greater for devices containing SiGe. This is an indication of velocity overshoot, which may enhance the performance of SiGe MOSFETs at deep submicron gate lengths. (author)

  16. Sulfur passivation for the formation of Si-terminated Al{sub 2}O{sub 3/}SiGe(0 0 1) interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Sardashti, Kasra [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA (United States); Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA (United States); Hu, Kai-Ting [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA (United States); Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA (United States); Tang, Kechao [Department of Materials Science and Engineering, Stanford University, CA (United States); Park, Sangwook; Kim, Hyonwoong [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA (United States); Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA (United States); Madisetti, Shailesh [Department of Nanoscale Science and Engineering, University at Albany—State University of New York, Albany, NY (United States); McIntyre, Paul [Department of Materials Science and Engineering, Stanford University, CA (United States); Oktyabrsky, Serge [Department of Nanoscale Science and Engineering, University at Albany—State University of New York, Albany, NY (United States); Siddiqui, Shariq; Sahu, Bhagawan [TD Research, GLOBALFOUNDRIES USA, Inc., Albany, NY (United States); Yoshida, Noami; Kachian, Jessica [Applied Materials, Inc., Santa Clara, CA (United States); Kummel, Andrew, E-mail: akummel@ucsd.edu [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA (United States)

    2016-03-15

    Graphical abstract: - Highlights: • Effect of wet sulfur passivation on the electrical properties of Al{sub 2}O{sub 3}/SiGe(0 0 1) interfaces has been determined. • EOT of 2.1 nm has been achieved for ALD Al{sub 2}O{sub 3} deposited directly on SiGe(0 0 1) surfaces. • Sulfur passivation has been found to passivate the Al{sub 2}O{sub 3} interface with Si−O−Al bonds. • Sulfur passivation is found to significantly reduce the GeO{sub x} or Ge−O−Al content at the Al{sub 2}O{sub 3}/SiGe interface therefore improving the reliability. • Sulfur passivation extends the surface stability prior to oxide ALD to up to an hour with no dramatic change in D{sub it}, C{sub ox} or V{sub FB} of the resulting devices. - Abstract: Sulfur passivation is used to electrically and chemically passivate the silicon–germanium (SiGe) surfaces before and during the atomic layer deposition (ALD) of aluminum oxide (Al{sub 2}O{sub 3}). The electrical properties of the interfaces were examined by variable frequency capacitance–voltage (C–V) spectroscopy. Interface compositions were determined by angle-resolved X-ray photoelectron spectroscopy (AR-XPS). The sulfur adsorbs to a large fraction of surface sites on the SiGe(0 0 1) surface, protecting the surface from deleterious surface reactions during processing. Sulfur passivation (a) improved the air stability of the cleaned surfaces prior to ALD, (b) increased the stability of the surface during high-temperature deposition, and (c) increased the Al{sub 2}O{sub 3} ALD nucleation density on SiGe, thereby lowering the leakage current. S passivation suppressed formation of Ge−O bonds at the interface, leaving the majority of the Al{sub 2}O{sub 3}–SiGe interface terminated with direct Si−O−Al bonding.

  17. InP-DHBT-on-BiCMOS technology with fT/fmax of 400/350 GHz for heterogeneous integrated millimeter-wave sources

    DEFF Research Database (Denmark)

    Kraemer, Tomas; Ostermay, Ina; Jensen, Thomas

    2013-01-01

    -100 GHz. The 0.8 × 5 μm2 InP DHBTs show fT/fmax of 400/350 GHz with an output power of more than 26 mW at 96 GHz. These are record values for a heterogeneously integrated transistor on silicon. As a circuit example, a 164-GHz signal source is presented. It features a voltage-controlled oscillator in Bi......This paper presents a novel InP-SiGe BiCMOS technology using wafer-scale heterogeneous integration. The vertical stacking of the InP double heterojunction bipolar transistor (DHBT) circuitry directly on top of the BiCMOS wafer enables ultra-broadband interconnects with

  18. Feasibility of automotive radar at frequencies beyond 100 GHz

    OpenAIRE

    Köhler, Mike; Hasch, Jürgen; Blöcher, Hans Ludwig; Schmidt, Lorenz-Peter

    2014-01-01

    Radar sensors are used widely in modern driver assistance systems. Available sensors nowadays often operate in the 77 GHz band and can accurately provide distance, velocity, and angle information about remote objects. Increasing the operation frequency allows improving the angular resolution and accuracy. In this paper, the technical feasibility to move the operation frequency beyond 100 GHz is discussed, by investigating dielectric properties of radome materials, the attenuation of rain and ...

  19. Multiparty quantum secret sharing based on GHZ states

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Tzonelih; Hwang, Cheng-Chieh [Department of Computer Science and Information Engineering, National Cheng Kung University, Tainan, 701 Taiwan (China); Li, Chuan-Ming, E-mail: hwangtl@ismail.csie.ncku.edu.tw [Department of Information Management, Shu-Zen College of Medicine and Management, Kaohsiung, 821 Taiwan (China)

    2011-04-15

    Gao (2009 Commun. Theor. Phys. 52 421-4) has proposed an efficient multiparty quantum secret sharing (MQSS) with two-photon three-dimensional Einstein-Podolsky-Rosen (EPR) pairs. This work shows that a similar idea can also be used to construct an MQSS using the Greenberger-Horne-Zeilinger (GHZ) states. Compared to other MQSSs using GHZ-related states, the newly proposed protocol is more efficient in the aspect of qubit utilization.

  20. Cold test of deep groove plarizer for 170 GHz ECCD system

    International Nuclear Information System (INIS)

    Saigusa, M.; Ookouti, K.; Sazawa, S.; Yuasa, S.; Takei, N.; Takahashi, K.; Sakamoto, K.; Imai, T.

    2001-01-01

    The single deep groove mirror was proposed as a new concept polarizer instead of the conventional two mirror polarizers for producing ordinary (or extraordinary) wave with high mode purity at an arbitrary injection angle in electron cyclotron current drive (ECCD) experiments. The estimated mode purity of O and X waves on the plasma surface is expected to be higher than about 93% for reasonable ECCD experimental conditions. The three types of deep groove mirrors, which are the rectangular groove mirror and the non-rectangular one, are manufactured and tested at the frequency range from 140 GHz to 170 GHz and the power level of 30 mW. The groove parameters are the period of 0.9-1 mm, the ridge width of 0.45-0.5 mm, and the groove depth of 1.98 mm, which is deeper than a wavelength at 170 GHz. The measured results of deep groove polarizers agree with the theoretical predictions, qualitatively. Those prove the feasibility of a single mirror polarizer for ECCD system

  1. Desain Antena Hexagonal Patch Array Berbasis Sistem Transfer Daya Wireless pada Frekuensi 2,4 GHz

    Directory of Open Access Journals (Sweden)

    Herma Nugroho R. A. K.

    2016-06-01

    Full Text Available Pada penelitian ini telah didesain antena hexagonal patch array yang dapat digunakan sebagai perangkat catu daya wireless. Antena hexagonal patch array ini didesain untuk menangkap gelombang radio (RF pada frekuensi 2,4 GHz yang dapat diaplikasikan sebagai antena pada Wireless Local Area Network (WLAN. Desain antena dilakukan menggunakan software CST Microwave studio, kemudian dilakukan pabrikasi dan pengukuran secara riil. Parameter pengujian antena hexagonal patch array meliputi return loss, Voltage Standing Wave Ratio (VSWR, gain, bandwidth, dan daya. Metode yang digunakan adalah pemodelan transmission line dan corporate feed line untuk pengaturan perubahan jarak antar patch antena. Perubahan variabel juga diteliti pengaruhnya terhadap parameter antena khususnya daya terima antena yang kemudian ditransmisikan ke rangkaian power harvester. Nilai parameter antena hasil simulasi menunjukkan nilai return loss adalah -33,38 dB, VSWR sebesar 1,041, gain sebesar 8,81 dBi, bandwidth adalah 0,084 GHz, daya sebesar 0,499 W (-3 dBm. Sedangkan parameter hasil pengukuran dari antena yang telah dipabrikasi adalah nilai return loss sebesar -33,21 dB, VSWR sebesar 1,048, gain sebesar 5 dBi, bandwidth adalah 0,145 GHz, daya sebesar -33 dBm.

  2. ARCADE 2 MEASUREMENT OF THE ABSOLUTE SKY BRIGHTNESS AT 3-90 GHz

    International Nuclear Information System (INIS)

    Fixsen, D. J.; Kogut, A.; Wollack, E.; Levin, S.; Seiffert, M.; Limon, M.; Lubin, P.; Mirel, P.; Singal, J.; Villela, T.; Wuensche, C. A.

    2011-01-01

    The ARCADE 2 instrument has measured the absolute temperature of the sky at frequencies 3, 8, 10, 30, and 90 GHz, using an open-aperture cryogenic instrument observing at balloon altitudes with no emissive windows between the beam-forming optics and the sky. An external blackbody calibrator provides an in situ reference. Systematic errors were greatly reduced by using differential radiometers and cooling all critical components to physical temperatures approximating the cosmic microwave background (CMB) temperature. A linear model is used to compare the output of each radiometer to a set of thermometers on the instrument. Small corrections are made for the residual emission from the flight train, balloon, atmosphere, and foreground Galactic emission. The ARCADE 2 data alone show an excess radio rise of 54 ± 6 mK at 3.3 GHz in addition to a CMB temperature of 2.731 ± 0.004 K. Combining the ARCADE 2 data with data from the literature shows an excess power-law spectrum of T = 24.1 ± 2.1 (K) (ν/ν 0 ) -2.599±0.036 from 22 MHz to 10 GHz (ν 0 = 310 MHz) in addition to a CMB temperature of 2.725 ± 0.001 K.

  3. Comparison of OQPSK and CPM for Communications at 60 GHz with a Nonideal Front End

    Directory of Open Access Journals (Sweden)

    Jimmy Nsenga

    2007-03-01

    Full Text Available Short-range digital communications at 60 GHz have recently received a lot of interest because of the huge bandwidth available at those frequencies. The capacity offered to the users could finally reach 2 Gbps, enabling the deployment of new multimedia applications. However, the design of analog components is critical, leading to a possible high nonideality of the front end (FE. The goal of this paper is to compare the suitability of two different air interfaces characterized by a low peak-to-average power ratio (PAPR to support communications at 60 GHz. On one hand, we study the offset-QPSK (OQPSK modulation combined with a channel frequency-domain equalization (FDE. On the other hand, we study the class of continuous phase modulations (CPM combined with a channel time-domain equalizer (TDE. We evaluate their performance in terms of bit error rate (BER considering a typical indoor propagation environment at 60 GHz. For both air interfaces, we analyze the degradation caused by the phase noise (PN coming from the local oscillators; and by the clipping and quantization errors caused by the analog-to-digital converter (ADC; and finally by the nonlinearity in the PA.

  4. Novel Radio Architectures for UWB, 60 GHz, and Cognitive Wireless Systems

    Directory of Open Access Journals (Sweden)

    Cabric Danijela

    2006-01-01

    Full Text Available There are several new radio systems which exploit novel strategies being made possible by the regulatory agencies to increase the availability of spectrum for wireless applications. Three of these that will be discussed are ultra-wideband (UWB, 60 GHz, and cognitive radios. The UWB approach attempts to share the spectrum with higher-priority users by transmitting at power levels that are so low that they do not cause interference. On the other hand, cognitive radios attempt to share spectra by introducing a spectrum sensing function, so that they are able to transmit in unused portions at a given time, place, and frequency. Another approach is to exploit the advances in CMOS technology to operate in frequency bands in the millimeter-wave region. 60 GHz operation is particularly attractive because of the 7 GHz of unlicensed spectrum that has been made available there. In this paper, we present an overview of novel radio architecture design approaches and address challenges dealing with high-frequencies, wide-bandwidths, and large dynamic-range signals encountered in these future wireless systems.

  5. Theoretical models for designing a 220-GHz folded waveguide backward wave oscillator

    International Nuclear Information System (INIS)

    Cai Jin-Chi; Chen Huai-Bi; Hu Lin-Lin; Ma Guo-Wu; Chen Hong-Bin; Jin Xiao

    2015-01-01

    In this paper, the basic equations of beam-wave interaction for designing the 220 GHz folded waveguide (FW) backward wave oscillator (BWO) are described. On the whole, these equations are mainly classified into small signal model (SSM), large signal model (LSM), and simplified small signal model (SSSM). Using these linear and nonlinear one-dimensional (1D) models, the oscillation characteristics of the FW BWO of a given configuration of slow wave structure (SWS) can be calculated by numerical iteration algorithm, which is more time efficient than three-dimensional (3D) particle-in-cell (PIC) simulation. The SSSM expressed by analytical formulas is innovatively derived for determining the initial values of the FW SWS conveniently. The dispersion characteristics of the FW are obtained by equivalent circuit analysis. The space charge effect, the end reflection effect, the lossy wall effect, and the relativistic effect are all considered in our models to offer more accurate results. The design process of the FW BWO tube with output power of watt scale in a frequency range between 215 GHz and 225 GHz based on these 1D models is demonstrated. The 3D PIC method is adopted to verify the theoretical design results, which shows that they are in good agreement with each other. (paper)

  6. Comparison of OQPSK and CPM for Communications at 60 GHz with a Nonideal Front End

    Directory of Open Access Journals (Sweden)

    Nsenga Jimmy

    2007-01-01

    Full Text Available Short-range digital communications at 60 GHz have recently received a lot of interest because of the huge bandwidth available at those frequencies. The capacity offered to the users could finally reach 2 Gbps, enabling the deployment of new multimedia applications. However, the design of analog components is critical, leading to a possible high nonideality of the front end (FE. The goal of this paper is to compare the suitability of two different air interfaces characterized by a low peak-to-average power ratio (PAPR to support communications at 60 GHz. On one hand, we study the offset-QPSK (OQPSK modulation combined with a channel frequency-domain equalization (FDE. On the other hand, we study the class of continuous phase modulations (CPM combined with a channel time-domain equalizer (TDE. We evaluate their performance in terms of bit error rate (BER considering a typical indoor propagation environment at 60 GHz. For both air interfaces, we analyze the degradation caused by the phase noise (PN coming from the local oscillators; and by the clipping and quantization errors caused by the analog-to-digital converter (ADC; and finally by the nonlinearity in the PA.

  7. 60-GHz Millimeter-wave Over Fiber with Directly Modulated Dual-mode Laser Diode

    Science.gov (United States)

    Tsai, Cheng-Ting; Lin, Chi-Hsiang; Lin, Chun-Ting; Chi, Yu-Chieh; Lin, Gong-Ru

    2016-01-01

    A directly modulated dual-mode laser diode (DMLD) with third-order intermodulation distortion (IMD3) suppression is proposed for a 60-GHz millimeter-wave over fiber (MMWoF) architecture, enabling new fiber-wireless communication access to cover 4-km single-mode-fiber (SMF) and 3-m wireless 16-QAM OFDM transmissions. By dual-mode injection-locking, the throughput degradation of the DMLD is mitigated with saturation effect to reduce its threshold, IMD3 power and relative intensity noise to 7.7 mA, −85 dBm and −110.4 dBc/Hz, respectively, providing huge spurious-free dynamic range of 85.8 dB/Hz2/3. This operation suppresses the noise floor of the DMLD carried QPSK-OFDM spectrum by 5 dB. The optical receiving power is optimized to restrict the power fading effect for improving the bit error rate to 1.9 × 10−3 and the receiving power penalty to 1.1 dB. Such DMLD based hybrid architecture for 60-GHz MMW fiber-wireless access can directly cover the current optical and wireless networks for next-generation indoor and short-reach mobile communications. PMID:27297267

  8. Design of 2.5 GHz broad bandwidth microwave bandpass filter at operating frequency of 10 GHz using HFSS

    Science.gov (United States)

    Jasim, S. E.; Jusoh, M. A.; Mahmud, S. N. S.; Zamani, A. H.

    2018-04-01

    Development of low losses, small size and broad bandwidth microwave bandpass filter operating at higher frequencies is an active area of research. This paper presents a new route used to design and simulate microwave bandpass filter using finite element modelling and realized broad bandwidth, low losses, small dimension microwave bandpass filter operating at 10 GHz frequency using return loss method. The filter circuit has been carried out using Computer Aid Design (CAD), Ansoft HFSS software and designed with four parallel couple line model and small dimension (10 × 10 mm2) using LaAlO3 substrate. The response of the microwave filter circuit showed high return loss -50 dB at operating frequency at 10.4 GHz and broad bandwidth of 2.5 GHz from 9.5 to 12 GHz. The results indicate the filter design and simulation using HFSS is reliable and have the opportunity to transfer from lab potential experiments to the industry.

  9. New results in development of MW output power gyrotrons for fusion systems

    International Nuclear Information System (INIS)

    Litvak, A.G.; Denisov, G.G.; Ilin, V.I.; Kurbatov, V.I.; Myasnikov, V.E.; Soluyanova, E.A.; Tai, E.M.; Usachev, S.V.; Zapevalov, V.E.

    2005-01-01

    The paper presents the latest achievements of the Russian gyrotron team in development of MW power gyrotrons for fusion installations. During two last years four new gyrotrons were designed and tested: a new version of 170 GHz gyrotron for ITER; multi-frequency (105-140 GHz) gyrotron for Asdex-Up, 84GHz gyrotron for LHD and 82.7 GHz gyrotron for SST-1. All these gyrotrons are equipped with diamond CVD windows and depressed collectors

  10. 77 FR 48097 - Operation of Radar Systems in the 76-77 GHz Band

    Science.gov (United States)

    2012-08-13

    ... modify the emission limits for vehicular radar systems operating within the 76-77 GHz band. Specifically.... 15.253 of the rules for vehicular radar systems operating in the 76-77 GHz band. Vehicular radars can... sensors operating in the 76-77 GHz band, the spectrum shall be investigated up to 231 GHz. (f) Fundamental...

  11. Capacitor-less memory cell fabricated on nano-scale strained Si on a relaxed SiGe layer-on-insulator

    International Nuclear Information System (INIS)

    Kim, Tae-Hyun; Park, Jea-Gun

    2013-01-01

    We investigated the combined effect of the strained Si channel and hole confinement on the memory margin enhancement for a capacitor-less memory cell fabricated on nano-scale strained Si on a relaxed SiGe layer-on-insulator (ε-Si SGOI). The memory margin for the ε-Si SGOI capacitor-less memory cell was higher than that of the memory cell fabricated on an unstrained Si-on-insulator (SOI) and increased with increasing Ge concentration of the relaxed SiGe layer; i.e. the memory margin for the ε-Si SGOI capacitor-less memory cell (138.6 µA) at a 32 at% Ge concentration was 3.3 times higher than the SOI capacitor-less memory cell (43 µA). (paper)

  12. Growth of light-emitting SiGe heterostructures on strained silicon-on-insulator substrates with a thin oxide layer

    Energy Technology Data Exchange (ETDEWEB)

    Baidakova, N. A., E-mail: banatale@ipmras.ru [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Bobrov, A. I. [University of Nizhny Novgorod (Russian Federation); Drozdov, M. N.; Novikov, A. V. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Pavlov, D. A. [University of Nizhny Novgorod (Russian Federation); Shaleev, M. V.; Yunin, P. A.; Yurasov, D. V.; Krasilnik, Z. F. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

    2015-08-15

    The possibility of using substrates based on “strained silicon on insulator” structures with a thin (25 nm) buried oxide layer for the growth of light-emitting SiGe structures is studied. It is shown that, in contrast to “strained silicon on insulator” substrates with a thick (hundreds of nanometers) oxide layer, the temperature stability of substrates with a thin oxide is much lower. Methods for the chemical and thermal cleaning of the surface of such substrates, which make it possible to both retain the elastic stresses in the thin Si layer on the oxide and provide cleaning of the surface from contaminating impurities, are perfecte. It is demonstrated that it is possible to use the method of molecular-beam epitaxy to grow light-emitting SiGe structures of high crystalline quality on such substrates.

  13. 47 CFR 25.136 - Licensing provisions for user transceivers in the 1.6/2.4 GHz, 1.5/1.6 GHz, and 2 GHz Mobile...

    Science.gov (United States)

    2010-10-01

    ...) Incorporation of ancillary terrestrial component base station into an L-band mobile-satellite service system... ancillary terrestrial component (ATC) base stations as defined in § 25.201 at its own risk and subject to... Applications and Licenses Earth Stations § 25.136 Licensing provisions for user transceivers in the 1.6/2.4 GHz...

  14. 60-GHz Millimeter-Wave Radio: Principle, Technology, and New Results

    Directory of Open Access Journals (Sweden)

    Nan Guo

    2006-12-01

    Full Text Available The worldwide opening of a massive amount of unlicensed spectra around 60 GHz has triggered great interest in developing affordable 60-GHz radios. This interest has been catalyzed by recent advance of 60-GHz front-end technologies. This paper briefly reports recent work in the 60-GHz radio. Aspects addressed in this paper include global regulatory and standardization, justification of using the 60-GHz bands, 60-GHz consumer electronics applications, radio system concept, 60-GHz propagation and antennas, and key issues in system design. Some new simulation results are also given. Potentials and problems are explained in detail.

  15. A Novel Oscillating Rectenna for Wireless Microwave Power Transmission

    Science.gov (United States)

    McSpadden, J. O.; Dickinson, R. M.; Fan, L.; Chang, K.

    1998-01-01

    A new concept for solid state wireless microwave power transmission is presented. A 2.45 GHz rectenna element that was designed for over 85% RF to dc power conversion efficiency has been used to oscillate at 3.3 GHz with an approximate 1% dc to RF conversion efficiency.

  16. A SiGe Quadrature Pulse Modulator for Superconducting Qubit State Manipulation

    Science.gov (United States)

    Kwende, Randy; Bardin, Joseph

    Manipulation of the quantum states of microwave superconducting qubits typically requires the generation of coherent modulated microwave pulses. While many off-the-shelf instruments are capable of generating such pulses, a more integrated approach is likely required if fault-tolerant quantum computing architectures are to be implemented. In this work, we present progress towards a pulse generator specifically designed to drive superconducing qubits. The device is implemented in a commercial silicon process and has been designed with energy-efficiency and scalability in mind. Pulse generation is carried out using a unique approach in which modulation is applied directly to the in-phase and quadrature components of a carrier signal in the 1-10 GHz frequency range through a unique digital-analog conversion process designed specifically for this application. The prototype pulse generator can be digitally programmed and supports sequencing of pulses with independent amplitude and phase waveforms. These amplitude and phase waveforms can be digitally programmed through a serial programming interface. Detailed performance of the pulse generator at room temperature and 4 K will be presented.

  17. 45-110 GHz Quad-Ridge Horn With Stable Gain and Symmetric Beam

    Science.gov (United States)

    Manafi, Sara; Al-Tarifi, Muhannad; Filipovic, Dejan S.

    2017-09-01

    A quad-ridge horn antenna with stabilized gain and minimum difference between Eand H-plane half-power beamwidths (HPBWs) is demonstrated for operation over 45-110 GHz bandwidth. Multistep flaring and corrugations on a finite ground plane are applied to obtain stable radiation patterns with 16-dBi minimum gain over the entire range. The computational studies are validated through measurements of a 3-D printed prototype using the direct metal laser sintering (DMLS) process. Accurate fabrication with achieved surface roughness of DMLS is a viable fabrication process for wideband horn antennas at millimeter-wave frequencies.

  18. Numerical design and analysis of parasitic mode oscillations for 95 GHz gyrotron beam tunnel

    Science.gov (United States)

    Kumar, Nitin; Singh, Udaybir; Yadav, Vivek; Kumar, Anil; Sinha, A. K.

    2013-05-01

    The beam tunnel, equipped with the high lossy ceramics, is designed for 95 GHz gyrotron. The geometry of the beam tunnel is optimized considering the maximum RF absorption (ideally 100%) and the suppression of parasitic oscillations. The excitation of parasitic modes is a concerning problem for high frequency, high power gyrotrons. Considering the problem of parasitic mode excitation in beam tunnel, a detail analysis is performed for the suppression of these kinds of modes. Trajectory code EGUN and CST Microwave Studio are used for the simulations of electron beam trajectory and electromagnetic analysis, respectively.

  19. Design of 28 GHz, 200 kW Gyrotron for ECRH Applications

    Science.gov (United States)

    Yadav, Vivek; Singh, Udaybir; Kumar, Nitin; Kumar, Anil; Deorani, S. C.; Sinha, A. K.

    2013-01-01

    This paper presents the design of 28 GHz, 200 kW gyrotron for Indian TOKAMAK system. The paper reports the designs of interaction cavity, magnetron injection gun and RF window. EGUN code is used for the optimization of electron gun parameters. TE03 mode is selected as the operating mode by using the in-house developed code GCOMS. The simulation and optimization of the cavity parameters are carried out by using the Particle-in-cell, three dimensional (3-D)-electromagnetic simulation code MAGIC. The output power more than 250 kW is achieved.

  20. Remote-Steering Antennas for 140 GHz Electron Cyclotron Heating of the Stellarator W7-X

    Directory of Open Access Journals (Sweden)

    Lechte C.

    2017-01-01

    Full Text Available For electron cyclotron resonance heating of the stellarator W7-X at IPP Greifswald, a 140 GHz/10 MW cw millimeter wave system has been built. Two out of 12 launchers will employ a remote-steering design. This paper describes the overall design of the two launchers, and design issues like input coupling structures, manufacturing of corrugated waveguides, optimization of the steering range, integration of vacuum windows, mitrebends and vacuum valves into the launchers, as well as low power tests of the finished waveguides.

  1. Ultra compact 45 GHz CMOS compatible Germanium waveguide photodiode with low dark current.

    Science.gov (United States)

    DeRose, Christopher T; Trotter, Douglas C; Zortman, William A; Starbuck, Andrew L; Fisher, Moz; Watts, Michael R; Davids, Paul S

    2011-12-05

    We present a compact 1.3 × 4 μm2 Germanium waveguide photodiode, integrated in a CMOS compatible silicon photonics process flow. This photodiode has a best-in-class 3 dB cutoff frequency of 45 GHz, responsivity of 0.8 A/W and dark current of 3 nA. The low intrinsic capacitance of this device may enable the elimination of transimpedance amplifiers in future optical data communication receivers, creating ultra low power consumption optical communications.

  2. SP-100 space nuclear power system

    International Nuclear Information System (INIS)

    Given, R.W.; Morgan, R.E.; Chi, J.W.H.; Westinghouse Electric Corp., Madison, PA)

    1984-01-01

    A baseline design concept for a 100 kWe nuclear reactor space power system is described. The concept was developed under contract from JPL as part of a joint program of the DOE, DOD, and NASA. The major technical and safety constraints influencing the selection of reactor operating parameters are discussed. A lithium-cooled compact fast reactor was selected as the best candidate system. The material selected for the thermoelectric conversion system was silicon germanium (SiGe) with gallium phosphide doping. Attention is given to the improved safety of the seven in-core control rod configuration

  3. The role of SiGe buffer in growth and relaxation of Ge on free-standing Si(001) nano-pillars.

    Science.gov (United States)

    Zaumseil, P; Kozlowski, G; Schubert, M A; Yamamoto, Y; Bauer, J; Schülli, T U; Tillack, B; Schroeder, T

    2012-09-07

    We study the growth and relaxation processes of Ge nano-clusters selectively grown by chemical vapor deposition on free-standing 90 nm wide Si(001) nano-pillars with a thin Si(0.23)Ge(0.77) buffer layer. We found that the dome-shaped SiGe layer with a height of about 28 nm as well as the Ge dot deposited on top of it partially relaxes, mainly by elastic lattice bending. The Si nano-pillar shows a clear compliance behavior-an elastic response of the substrate on the growing film-with the tensile strained top part of the pillar. Additional annealing at 800 °C leads to the generation of misfit dislocation and reduces the compliance effect significantly. This example demonstrates that despite the compressive strain generated due to the surrounding SiO(2) growth mask it is possible to realize an overall tensile strain in the Si nano-pillar and following a compliant substrate effect by using a SiGe buffer layer. We further show that the SiGe buffer is able to improve the structural quality of the Ge nano-dot.

  4. Influence of the crystallization process on the luminescence of multilayers of SiGe nanocrystals embedded in SiO2

    International Nuclear Information System (INIS)

    Avella, M.; Prieto, A.C.; Jimenez, J.; Rodriguez, A.; Sangrador, J.; Rodriguez, T.; Ortiz, M.I.; Ballesteros, C.

    2008-01-01

    Multilayers of SiGe nanocrystals embedded in an oxide matrix have been fabricated by low-pressure chemical vapor deposition of SiGe and SiO 2 onto Si wafers (in a single run at 390 deg. C and 50 mTorr, using GeH 4 , Si 2 H 6 and O 2 ) followed by a rapid thermal annealing treatment to crystallize the SiGe nanoparticles. The main emission band is located at 400 nm in both cathodoluminescence and photoluminescence experiments at 80 K and also at room temperature. The annealing conditions (temperatures ranging from 700 to 1000 deg. C and for times of 30 and 60 s) have been investigated in samples with different diameter of the nanoparticles (from ∼3 to ≥5 nm) and oxide interlayer thickness (15 and 35 nm) in order to establish a correlation between the crystallization of the nanoparticles, the degradation of their composition by Ge diffusion and the intensity of the luminescence emission band. Structures with small nanoparticles (3-4.5 nm) separated by thick oxide barriers (∼35 nm) annealed at 900 deg. C for 60 s yield the maximum intensity of the luminescence. An additional treatment at 450 deg. C in forming gas for dangling-bond passivation increases the intensity of the luminescence band by 25-30%

  5. Test result of 5 GHz, 500 kW CW prototype klystron for KSTAR LHCD system

    Energy Technology Data Exchange (ETDEWEB)

    Do, H., E-mail: heejindo@nfri.re.kr [Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Park, S. [Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Jeong, J.H.; Bae, Y.S.; Yang, H.L. [National Fusion Research Institute, Daejeon 350-333 (Korea, Republic of); Delpech, L.; Magne, R.; Hoang, G.T. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Park, H.; Cho, M.H.; Namkung, W. [Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

    2011-10-15

    A 5 GHz LHCD system is being designed for current drive and profile modification necessary for AT mode and steady-state operation of the KSTAR tokamak. A prototype 500 kW CW klystron operating at 5 GHz was developed for the steady-state RF source. In this klystron, a multi-cell cavity is introduced to reduce cavity voltage and ohmic power loss. The klystron is designed with a triode system for optimization of gain, efficiency and beam control. The high voltage for the cathode is turned by using a thyristor switching system at the low voltage transformer unit. For anode voltage control, a mod-anode voltage divider system is used which utilize the parallel-circuit of the FET switch and Zener diodes. The RF output power of the klystron was 300 kW for 800 s and 450 kW for 20 s. The maximal temperature at collector top surface was 83 deg. C and power loss at the tube body did not exceed 10 kW, the interlock level for the protection of the klystron. Detailed results of the klystron system test and commissioning are presented.

  6. Chronic exposure of a honey bee colony to 2.45 GHz continuous wave microwaves

    Science.gov (United States)

    Westerdahl, B. B.; Gary, N. E.

    1981-01-01

    A honey bee colony (Apis mellifera L.) was exposed 28 days to 2.45 GHz continuous wave microwaves at a power density (1 mW/sq cm) expected to be associated with rectennae in the solar power satellite power transmission system. Differences found between the control and microwave-treated colonies were not large, and were in the range of normal variation among similar colonies. Thus, there is an indication that microwave treatment had little, if any, effect on (1) flight and pollen foraging activity, (2) maintenance of internal colony temperature, (3) brood rearing activity, (4) food collection and storage, (5) colony weight, and (6) adult populations. Additional experiments are necessary before firm conclusions can be made.

  7. Design of a 5 GHz window in a lower hybrid r.f. system

    International Nuclear Information System (INIS)

    Maebara, S.; Ikeda, Y.; Seki, M.; Imai, T.

    1995-01-01

    A new pill-box window at a frequency of 5GHz, which has an oversized length in both the axial and the radial direction, has been designed to reduce the r.f. power density and the electric field strength at the ceramics. The dimension of the new pill-box is optimized from the numerical calculation and a voltage standing-wave ratio of less than 1.02 is obtained. The r.f. power density and the maximum electric field strength are reduced to about 40% and 66% of the standard pill-box window respectively. It is evaluated that the power capability of the new oversized pill-box window by cooling edge of ceramics is more than 500kW with continuous-wave operation. ((orig.))

  8. A 311-GHz Fundamental Oscillator Using InP HBT Technology

    Science.gov (United States)

    Gaier, Todd; Fung, King Man; Samoska, Lorene; Radisic, Vesna; Sawdai, Donald; Scott, Dennis; Deal, W.R.

    2010-01-01

    amount of feedback than the common-emitter design, therefore preserving device gain, and was chosen for the oscillator design. The submillimeter-wave region offers several advantages for sensors and communication systems, such as high resolution and all-weather imaging due to the short-wavelength, and improved communication speeds by access to greater frequency bandwidth. This oscillator circuit is a prototype of the first HBT oscillator operating above 300 GHz. Additional development is necessary to increase the output power of the circuit for radar and imaging applications.

  9. Icecube: Spaceflight Validation of an 874-GHz Submillimeter Wave Radiometer for Ice Cloud Remote Sensing

    Science.gov (United States)

    Wu, D. L.; Esper, J.; Ehsan, N.; Piepmeier, J. R.; Racette, P.

    2014-12-01

    Ice clouds play a key role in the Earth's radiation budget, mostly through their strong regulation of infrared radiation exchange. Submillimeter wave remote sensing offers a unique capability to improve cloud ice measurements from space. At 874 GHz cloud scattering produces a larger brightness temperature depression from cirrus than lower frequencies, which can be used to retrieve vertically-integrated cloud ice water path (IWP) and ice particle size. The objective of the IceCube project is to retire risks of 874-GHz receiver technology by raising its TRL from 5 to 7. The project will demonstrate, on a 3-U CubeSat in a low Earth orbit (LEO) environment, the 874-GHz receiver system with noise equivalent differential temperature (NEDT) of ~0.2 K for 1-second integration and calibration error of 2.0 K or less as measured from deep-space observations. The Goddard Space Flight Center (GSFC) is partnering with Virginia Diodes, Inc (VDI) to qualify commercially available 874-GHz receiver technology for spaceflight, and demonstrate the radiometer performance. The instrument (submm-wave cloud radiometer, or SCR), along with the CubeSat system developed and integrated by GSFC, will be ready for launch in two years. The instrument subsystem includes a reflector antenna, sub-millimeter wave mixer, frequency multipliers and stable local oscillator, an intermediate frequency (IF) circuit with noise injection, and data-power boards. The mixer and frequency multipliers are procured from VDI with GSFC insight into fabrication and testing processes to ensure scalability to spaceflight beyond TRL 7. The remaining components are a combination of GSFC-designed and commercial off-the-shelf (COTS) at TRLs of 5 or higher. The spacecraft system is specified by GSFC and comprises COTS components including three-axis stabilizer and sun sensor, GPS receiver, deployable solar arrays, UHF radio, and 2 GB of on-board storage. The spacecraft and instrument are integrated and flight qualified

  10. Controlled and secure direct communication using GHZ state and teleportation

    International Nuclear Information System (INIS)

    Gao, T.

    2004-01-01

    A theoretical scheme for controlled and secure direct communication is proposed. The communication is based on GHZ state and controlled quantum teleportation. After insuring the security of the quantum channel (a set of qubits in the GHZ state), alice encodes the secret message directly on a sequence of particle states in the GHZ state and transmits them to Bob, supervised by Charlie using controlled quantum teleportation. Bob can read out the encoded messages directly by the measurement on his qubits. In this scheme, the controlled quantum teleportation transmits alice's message without revealing any information to a potential eavesdropper. Because there is not a transmission of the qubit carrying the secret messages between Alice and Bob in the public channel, it is completely secure for controlled and direct secret communication if a perfect quantum channel is used. The feature of this scheme is that the communication between two sides depends on the agreement of a third side. (orig.)

  11. A CMOS frequency generation module for 60-GHz applications

    International Nuclear Information System (INIS)

    Zhou Chunyuan; Zhang Lei; Wang Hongrui; Qian He

    2012-01-01

    A frequency generation module for 60-GHz transceivers and phased array systems is presented in this paper. It is composed of a divide-by-2 current mode logic divider (CML) and a doubler in push-push configuration. Benefiting from the CML structure and push-push configuration, the proposed frequency generation module has a wide operating frequency range to cover process, voltage, and temperature variation. It is implemented in a 90-nm CMOS process, and occupies a chip area of 0.64 × 0.65 mm 2 including pads. The measurement results show that the designed frequency generation module functions properly with input frequency over 15 GHz to 25 GHz. The whole chip dissipates 12.1 mW from a 1.2-V supply excluding the output buffers. (semiconductor integrated circuits)

  12. Feasibility study of the EU home team on a 170 GHz 1 MW CW gyrotron for ECH on ITER

    International Nuclear Information System (INIS)

    Iatrou, C.T.; Kern, S.; Thumm, M.; Moebius, A.; Nickel, H.U.; Horajitra, P.; Wien, A.; Tran, T.M.; Bon Mardion, G.; Pain, M.; Tonon, G.

    1995-03-01

    The gyrotron system for ECH and burn control on ITER requires at least 50 MW of RF power at frequencies near 170 GHz operating in CW. To meet these requirements, high efficiency gyrotron tubes with ≥1 MW power output capability are necessary, as well as simple coupling to either a quasi-optical or waveguide transmission line. The paper reports the feasibility study on the design of an ITER-relevant gyrotron oscillator at 170 GHz, 1 MW CW employing a diode electron gun, an advanced internal quasi-optical converter, a cryogenically cooled single disk sapphire window, and a depressed potential collector. The operating mode selection and the cavity design is a compromise between many design constraints. (author) 18 figs., 6 tabs., 21 refs

  13. Validation of the superconducting 3.9 GHz cavity package for the European X-ray Free Electron Laser

    Science.gov (United States)

    Maiano, C. G.; Branlard, J.; Hüning, M.; Jensch, K.; Kostin, D.; Matheisen, A.; Möller, W.-D.; Sulimov, A.; Vogel, E.; Bosotti, A.; Chen, J. F.; Moretti, M.; Paparella, R.; Pierini, P.; Sertore, D.

    2017-04-01

    A full test of the cavity package concept under realistic operating condition was a necessary step before the assembly of the European XFEL (EXFEL) 3.9 GHz superconducting system and its installation in the accelerator. One cavity, equipped with magnetic shielding, power coupler and frequency tuner has been tested in a specially designed single cavity cryostat in one of the test benches of the DESY Accelerator Module Test Facility (AMTF). The cavity was operated at high pulsed power up to an accelerating field of 24 MV /m , above the quench accelerating field of 21 MV /m achieved during the continuous wave (CW) vertical qualification test and with a large margin with respect to the EXFEL maximum operating specification of 15 MV /m for the 3.9 GHz system. All subsystems under test—coupler, tuner, waveguide tuners, low level radio-frequency (LLRF) system—were qualified to their design performances.

  14. Demonstration of a Submillimeter-Wave HEMT Oscillator Module at 330 GHz

    Science.gov (United States)

    Radisic, Vesna; Deal, W. R.; Mei, X. B.; Yoshida, Wayne; Liu, P. H.; Uyeda, Jansen; Lai, Richard; Samoska, Lorene; Fung, King Man; Gaier, Todd; hide

    2010-01-01

    In this work, radial transitions have been successfully mated with a HEMT-based MMIC (high-electron-mobility-transistor-based monolithic microwave integrated circuit) oscillator circuit. The chip has been assembled into a WR2.2 waveguide module for the basic implementation with radial E-plane probe transitions to convert the waveguide mode to the MMIC coplanar waveguide mode. The E-plane transitions have been directly integrated onto the InP substrate to couple the submillimeter-wave energy directly to the waveguides, thus avoiding wire-bonds in the RF path. The oscillator demonstrates a measured 1.7 percent DC-RF efficiency at the module level. The oscillator chip uses 35-nm-gate-length HEMT devices, which enable the high frequency of oscillation, creating the first demonstration of a packaged waveguide oscillator that operates over 300 GHz and is based on InP HEMT technology. The oscillator chip is extremely compact, with dimensions of only 1.085 x 320 sq mm for a total die size of 0.35 sq mm. This fully integrated, waveguide oscillator module, with an output power of 0.27 mW at 330 GHz, can provide low-mass, low DC-power-consumption alternatives to existing local oscillator schemes, which require high DC power consumption and large mass. This oscillator module can be easily integrated with mixers, multipliers, and amplifiers for building high-frequency transmit and receive systems at submillimeter wave frequencies. Because it requires only a DC bias to enable submillimeter wave output power, it is a simple and reliable technique for generating power at these frequencies. Future work will be directed to further improving the applicability of HEMT transistors to submillimeter wave and terahertz applications. Commercial applications include submillimeter-wave imaging systems for hidden weapons detection, airport security, homeland security, and portable low-mass, low-power imaging systems

  15. Microwave sintering of zirconia toughened alumina at 28GHz

    International Nuclear Information System (INIS)

    Samandi, M.; Ji, H.; Miyake, S.

    1998-01-01

    Microwave radiation from a 10 kW, CW gyrotron operating at 28 GHz was employed to sinter 10% zirconia toughened alumina (ZTA) ceramic samples. It has been established that the use of millimetre wave radiation circumvents the difficulties encountered during the sintering of ceramics, i e. formation of hot spot, by radiation at industrially permissible frequency of 2.45GHz. Further, careful density measurement and microstructural characterisation of mm- wave and conventionally sintered samples by XRD, SEM and TEM has unequivocally demonstrated the effectiveness of mm-wave radiation for obtaining high density ceramics at lower sintering temperatures. Copyright (1998) Australasian Ceramic Society

  16. 24 GHz cmWave Radio Propagation Through Vegetation

    DEFF Research Database (Denmark)

    Rodriguez, Ignacio; Abreu, Renato Barbosa; Portela Lopes de Almeida, Erika

    2016-01-01

    This paper presents a measurement-based analysis of cm-wave radio propagation through vegetation at 24 GHz. A set of dedicated directional measurements were performed with horn antennas located close to street level inside a densely-vegetated area illuminated from above. The full azimuth was exam......This paper presents a measurement-based analysis of cm-wave radio propagation through vegetation at 24 GHz. A set of dedicated directional measurements were performed with horn antennas located close to street level inside a densely-vegetated area illuminated from above. The full azimuth...

  17. Characterization of a 300-GHz Transmission System for Digital Communications

    Science.gov (United States)

    Hudlička, Martin; Salhi, Mohammed; Kleine-Ostmann, Thomas; Schrader, Thorsten

    2017-08-01

    The paper presents the characterization of a 300-GHz transmission system for modern digital communications. The quality of the modulated signal at the output of the system (error vector magnitude, EVM) is measured using a vector signal analyzer. A method using a digital real-time oscilloscope and consecutive mathematical processing in a computer is shown for analysis of signals with bandwidths exceeding that of state-of-the-art vector signal analyzers. The uncertainty of EVM measured using the real-time oscilloscope is open to analysis. Behaviour of the 300-GHz transmission system is studied with respect to various modulation schemes and different signal symbol rates.

  18. Ultra-wideband and 60 GHz communications for biomedical applications

    CERN Document Server

    Yuce, Mehmet R

    2013-01-01

    This book investigates the design of devices, systems, and circuits for medical applications using the two recently established frequency bands: ultra-wideband (3.1-10.6 GHz) and 60 GHz ISM band. These two bands provide the largest bandwidths available for communication technologies and present many attractive opportunities for medical applications. The applications of these bands in healthcare are wireless body area network (WBAN), medical imaging, biomedical sensing, wearable and implantable devices, fast medical device connectivity, video data transmission, and vital signs monitoring. The r

  19. Molecular astronomy using heterodyne detection at 691 GHz

    International Nuclear Information System (INIS)

    Fetterman, H.R.; Buhl, D.

    1984-01-01

    Observations of the CO J 6 - 5 transition at 691 GHz in new interstellar and planetary sources have been made. The heterodyne receiver uses an optically pumped laser local oscillator and a quasi-optical Schottky diode mixer, with measured noise temperatures consistently under 4000 K (double sideband). Continued improvements in system performance and antenna coupling have made possible the mapping of 691 GHz emission from W3, and the detection of CO J 5 - 6 absorption in the atmosphere of Venus. A detailed description of the instrumentation and recent observational data are provided. 14 references

  20. Experimental evidence of E × B plasma rotation in a 2.45 GHz hydrogen discharge

    Energy Technology Data Exchange (ETDEWEB)

    Cortázar, O. D., E-mail: daniel.cortazar@uclm.es [Institute for Energy Research-INEI, University of Castilla-La Mancha, C.J. Cela s/n, 13170 Ciudad Real (Spain); Megía-Macías, A. [CERN, BE-ABP-HSL Department, CH1211 Geneva (Switzerland); E.S.S. Bilbao, Polígono Ugaldeguren III, A-7B, 48170 Zamudio (Spain); Tarvainen, O.; Koivisto, H. [Department of Physics, Accelerator Laboratory, University of Jyväskylä, PO Box 35 (YFL), 40500 Jyväskylä (Finland)

    2015-12-15

    An experimental observation of a rotating plasma structure in a 2.45 GHz microwave-driven hydrogen discharge is reported. The rotation is presumably produced by E × B drift. The formation of the rotating plasma structure is sensitive to the strength of the off-resonance static magnetic field. The rotation frequency is on the order of 10 kHz and is affected by the neutral gas pressure and applied microwave power.

  1. Experimental evidence of E × B plasma rotation in a 2.45 GHz hydrogen discharge

    International Nuclear Information System (INIS)

    Cortázar, O. D.; Megía-Macías, A.; Tarvainen, O.; Koivisto, H.

    2015-01-01

    An experimental observation of a rotating plasma structure in a 2.45 GHz microwave-driven hydrogen discharge is reported. The rotation is presumably produced by E × B drift. The formation of the rotating plasma structure is sensitive to the strength of the off-resonance static magnetic field. The rotation frequency is on the order of 10 kHz and is affected by the neutral gas pressure and applied microwave power

  2. RECENT DEVELOPMENTS ON THE 110 GHz ELECTRON CYCLOTRON INSTATLLATION ON THE DIII-D TOKAMAK

    International Nuclear Information System (INIS)

    PONCE, D.; CALLIS, R.W.; CARY, W.P.; FERRON, J.R.; GREEN, M.; GRUNLOH, H.J.; GORELOV, Y.; LOHR, J.; ELLIS, R.A.

    2002-01-01

    OAK A271 RECENT DEVELOPMENTS ON THE 110 GHZ ELECTRON CYCLOTRON INSTALLATION ON THE DIII-D TOKAMAK. Significant improvements are being implement4ed to the capability of the 110 GHz electron cyclotron system on the DIII-D tokamak. Chief among these is the addition of the fifth and sixth 1 MW class gyrotrons, increasing the power available for auxiliary heating and current drive by nearly 60%. These tubes use artificially grown diamond rf output windows to obtain high power with long pulse capability. The beams from these tubes are nearly Gaussian, facilitating coupling to the waveguide. A new fully articulating dual launcher capable of high speed spatial scanning has been designed and tested. The launcher has two axis independent steering for each waveguide. the mirrors can be rotated at up to 100 o /s. A new feedback system linking the DIII-D Plasma Control System (PCS) with the gyrotron beam voltage waveform generators permits real-time feedback control of some plasma properties such as electron temperature. The PCS can use a variety of plasma monitors to generate its control signal, including electron cyclotron emission and Mirnov probes. Electron cyclotron heating and electron cyclotron current drive (ECH and ECCD) were used during this year's DIII-D experimental campaign to control electron temperature, density, and q profiles, induce an ELM-free H-mode, and suppress the m=2/n=1 neoclassical tearing mode. The new capabilities have expanded the role of EC systems in tokamak plasma control

  3. Performance enhancement in p-channel charge-trapping flash memory devices with Si/Ge super-lattice channel and band-to-band tunneling induced hot-electron injection

    International Nuclear Information System (INIS)

    Liu, Li-Jung; Chang-Liao, Kuei-Shu; Jian, Yi-Chuen; Wang, Tien-Ko; Tsai, Ming-Jinn

    2013-01-01

    P-channel charge-trapping flash memory devices with Si, SiGe, and Si/Ge super-lattice channel are investigated in this work. A Si/Ge super-lattice structure with extremely low roughness and good crystal structure is obtained by precisely controlling the epitaxy thickness of Ge layer. Both programming and erasing (P/E) speeds are significantly improved by employing this Si/Ge super-lattice channel. Moreover, satisfactory retention and excellent endurance characteristics up to 10 6 P/E cycles with 3.8 V memory window show that the degradation on reliability properties is negligible when super-lattice channel is introduced. - Highlights: ► A super-lattice structure is proposed to introduce more Ge content into channel. ► Super-lattice structure possesses low roughness and good crystal structure. ► P-channel flash devices with Si, SiGe, and super-lattice channel are investigated. ► Programming/erasing speeds are significantly improved. ► Reliability properties can be kept for device with super-lattice channel

  4. Characterization of Nanocrystalline SiGe Thin Film Solar Cell with Double Graded-Dead Absorption Layer

    Directory of Open Access Journals (Sweden)

    Chao-Chun Wang

    2012-01-01

    Full Text Available The nanocrystalline silicon-germanium (nc-SiGe thin films were deposited by high-frequency (27.12 MHz plasma-enhanced chemical vapor deposition (HF-PECVD. The films were used in a silicon-based thin film solar cell with graded-dead absorption layer. The characterization of the nc-SiGe films are analyzed by scanning electron microscopy, UV-visible spectroscopy, and Fourier transform infrared absorption spectroscopy. The band gap of SiGe alloy can be adjusted between 0.8 and 1.7 eV by varying the gas ratio. For thin film solar cell application, using double graded-dead i-SiGe layers mainly leads to an increase in short-circuit current and therefore cell conversion efficiency. An initial conversion efficiency of 5.06% and the stabilized efficiency of 4.63% for an nc-SiGe solar cell were achieved.

  5. High-aspect-ratio and high-flatness Cu3(SiGe) nanoplatelets prepared by chemical vapor deposition.

    Science.gov (United States)

    Klementová, Mariana; Palatinus, Lukás; Novotný, Filip; Fajgar, Radek; Subrt, Jan; Drínek, Vladislav

    2013-06-01

    Cu3(SiGe) nanoplatelets were synthesized by low-pressure chemical vapor deposition of a SiH3C2H5/Ge2(CH3)6 mixture on a Cu-substrate at 500 degrees C, total pressure of 110-115 Pa, and Ge/Si molar ratio of 22. The nanoplatelets with composition Cu76Si15Ge12 are formed by the 4'-phase, and they are flattened perpendicular to the [001] direction. Their lateral dimensions reach several tens of micrometers in size, but they are only about 50 nm thick. Their surface is extremely flat, with measured root mean square roughness R(q) below 0.2 nm. The nanoplatelets grow via the non-catalytic vapor-solid mechanism and surface growth. In addition, nanowires and nanorods of various Cu-Si-Ge alloys were also obtained depending on the experimental conditions. Morphology of the resulting Cu-Si-Ge nanoobjects is very sensitive to the experimental parameters. The formation of nanoplatelets is associated with increased amount of Ge in the alloy.

  6. Depth profile of strain and composition in Si/Ge dot multilayers by microscopic phonon Raman spectroscopy

    International Nuclear Information System (INIS)

    Tan, P.H.; Bougeard, D.; Abstreiter, G.; Brunner, K.

    2005-01-01

    We characterized strain and Ge content depending on depth in a self-assembled Si/Ge dot multilayer by scanning a microscopic Raman probe at a (110) cleavage plane. The multilayer structure was deposited by molecular-beam epitaxy on a (001) Si substrate and consisted of 80 periods, each of them composed by 25 nm Si spacers and 8 monolayer Ge forming laterally and vertically uncorrelated islands with a height of 2 nm and a lateral diameter of about 20 nm. An average biaxial strain of -3.5% within the core regions of islands is determined from the splitting of longitudinal and transversal optical Ge-Ge phonon modes observed in polarized Raman measurements. The absolute mode frequencies further enable analysis of a Ge content of 0.82. The analyzed strain and composition of islands are nearly independent from depths below the sample surface. This indicates well-controlled deposition parameters and negligible intermixing during deposition of subsequent layers. These Raman results are in agreement with x-ray diffraction data. Small, local Raman frequency shifts were observed and discussed with respect to partial elastic strain relaxation of the multilayer stack after cleavage, undefined Raman-scattering geometries at the sample edge, and local heating by the laser probe

  7. Amorphous-crystalline interface evolution during Solid Phase Epitaxy Regrowth of SiGe films amorphized by ion implantation

    International Nuclear Information System (INIS)

    D'Angelo, D.; Piro, A.M.; Mirabella, S.; Bongiorno, C.; Romano, L.; Terrasi, A.; Grimaldi, M.G.

    2007-01-01

    Transmission Electron Microscopy was combined with Time Resolved Reflectivity to study the amorphous-crystalline (a-c) interface evolution during Solid Phase Epitaxy Regrowth (SPER) of Si 0.83 Ge 0.17 films deposited on Si by Molecular Beam Epitaxy and amorphized with Ge + ion implantation. Starting from the Si/SiGe interface, a 20 nm thick layer regrows free of defects with the same SPER rate of pure Si. The remaining SiGe regrows with planar defects and dislocations, accompanied by a decrease of the SPER velocity. The sample was also studied after implantation with B or P. In these cases, the SPER rate raises following the doping concentration profile, but no difference in the defect-free layer thickness was observed compared to the un-implanted sample. On the other hand, B or P introduction reduces the a-c interface roughness, while B-P co-implantation produces roughness comparable to the un-implanted sample

  8. 4 GHz ionospheric scintillations observed at Taipei

    International Nuclear Information System (INIS)

    Huang, Y.N.; Jeng, B.S.

    1978-01-01

    In a study of ionospheric scintillations 3950 MHz beacon signals from geostationary communication satellites Intelsat-IV-F8 and Intelsat-IV-F1 were recorded on a strip chart and magnetic tape at the Taipei Earth Station. While the strip charts were used to monitor the occurrence of the scintillation, the magnetic tape output was digitized and processed by a computerized system to yield a detailed analysis of scintillation events. It was found that diurnal variations were similar to the diurnal patterns of sporadic E at greater than 5 MHz and VHF band ionospheric scintillations during daytime as reported by Huang (1978). Eight typical scintillation events were selected for the calculation of the scintillation index, S4, and other parameters. The mean S4 index for the 8 events was found to be 0.15. Numerical and graphic results are presented for the cumulative amplitude distributions, message reliability, autocorrelation functions and power spectra

  9. 10 GHz multicharged-heavy-ion source CAPRICE for all metallic and gaseous elements

    International Nuclear Information System (INIS)

    Bourg, F.; Geller, R.; Jacquot, B.

    1987-01-01

    A new compact multiply charged E.C.R. ion source completely enclosed by an iron return yoke is described. A new coaxial 10 GHz microwave accessibility is operating. This allows a very compact two stages source in an entirely removable vacuum chamber and a very easy increasing possibility of the axial magnetic field value. Then two different working modes are possible. A classical mode (ω ce =ω rf , 100% cw, rf power 300 W, coils supply 20 kW) gives same performance than all the other reliable larger 10 GHz sources. A second mode (100% cw, rf power 600 W, coils supply 33 kW) operates with an additional resonant surface ω ce =2ω rf and increases by a factor 3 or 4 all currents on high charge states. Total extraction current is multiplied by a factor of 4 just as it would do by using a classical 20 GHz source by increase in density. This new resonant surface is unfortunately stopped in its radial part by the wall of the vacuum chamber due to a too low 10 GHz sextupole (0,4 T). Presently a better sextupole (0,8 T) is being built in order to work with both whole resonant surfaces inside the plasma chamber and perhaps so to improve charge states distribution by rising the plasma life time. On the other hand both the removable vacuum chamber and the coaxial rf feeder are well fitted to produce all metallic ions in long run and high intensity by working without any insulator inside the plasma chamber and by a good cleaning possibility. One shows cw spectra of 10 metallic elements from Al to Au and one can observe an exponential decrease for Ca, Ag and Au. This remark indicates a possible easy way to yield high charge states of all metals. One can expect to regulate all the lightest elements like Al, Si, Fe, Ni, Mo, Ta and W for 100 h. For example a good (within 1%) regulation of a 15 μA 56 Fe 7+ for 10 h is partly shown. (orig.)

  10. Variability of GPS Radio Sources at 5 GHz

    Indian Academy of Sciences (India)

    GPS) radio sources at 5 GHz and find that about one-third of them show considerable Inter-Month Variability (IMV), and these IMV phenomena are likely to be caused by interstellar scintillation (ISS). Furthermore, we find that those showing IMV ...

  11. Laboratory Heterodyne Spectrometers Operating at 100 and 300 GHZ

    Science.gov (United States)

    Maßen, Jakob; Wehres, Nadine; Hermanns, Marius; Lewen, Frank; Heyne, Bettina; Endres, Christian; Graf, Urs; Honingh, Netty; Schlemmer, Stephan

    2017-06-01

    Two new laboratory heterodyne emission spectrometers are presented that are currently used for high-resolution rotational spectroscopy of complex organic molecules. The room temperature heterodyne receiver operating between 80-110 GHz, as well as the SIS heterodyne receiver operating between 270-370 GHz allow access to two very important frequency regimes, coinciding with Bands 3 and 7 of the ALMA (Atacama Large Millimeter Array) telescope. Taking advantage of recent progresses in the field of mm/submm technology, we build these two spectrometers using an XFFFTS (eXtended Fast Fourier Transform Spectrometer) for spectral acquisition. The instantaneous bandwidth is 2.5 GHz in a single sideband, spread over 32768 channels. Thus, the spectral resolution is about 76 kHz per channel and thus comparable to high resolution spectra from telescopes. Both receivers are operated in double sideband mode resulting in a total instantaneous bandwidth of 5 GHz. The system performances, in particular the noise temperatures and stabilities are presented. Proof-of-concept is demonstrated by showing spectra of methyl cyanide obtained with both spectrometers. While the transition frequencies for this molecule are very well known, intensities of those transitions can also be determined with high accuracy using our new instruments. This additional information shall be exploited in future measurements to improve spectral predictions for astronomical observations. Other future prospects concern the study of more complex organic species, such as ethyl cyanide. These aspects of the new instruments as well as limitations of the two distinct receivers will be discussed.

  12. Characterisation of propagation in 60 GHz radio channels (invited)

    NARCIS (Netherlands)

    Smulders, P.F.M.; Correia, L.M.

    1997-01-01

    Narrowband as well as wideband measurements have been performed in various indoor and outdoor environments in order to enable the development of reliable prediction models for 60 GHz radio channels. In addition, results of deterministic modelling on the basis of geometric ray-tracing have been

  13. Sideband Separating Mixer for 600-720 GHz

    NARCIS (Netherlands)

    Khudchenko, Andrey; Hesper, Ronald; Barychev, Andrey; Gerlofma, Gerrit; Mena, Patricio; Zijlstra, Tony; Klapwijk, Teun; Spaans, Marco; Kooi, Jacob W.; Zhang, C; Zhang, XC; Siegel, PH; He, L; Shi, SC

    2010-01-01

    The ALMA Band 9 receiver cartridge (600-720 GHz) based on Dual Sideband (DSB) superconductor-insulator-superconductor (SIS) mixer is currently in full production. In the case of spectral line observations, the integration time to reach a certain signal-to-noise level can be reduced by about a factor

  14. Rain-induced bistatic scattering at 60 GHz

    NARCIS (Netherlands)

    Zanden, van der H.T.; Watson, R.J.; Herben, M.H.A.J.

    2007-01-01

    This paper presents the results of a study into the modeling and prediction of rain-induced bistatic scattering at 60 GHz. The bistatic radar equation together withMie theory is applied as the basis for calculating the scattering. Together with the attenuation induced by the medium before and after

  15. Logo Antenna for 5.8 GHz Wireless Communications (invited)

    DEFF Research Database (Denmark)

    Jørgensen, Kasper Lüthje; Jakobsen, Kaj Bjarne

    2016-01-01

    A logo antenna for the 5.8 GHz ISM band is presented. The idea behind the logo antenna is to use the company or university logo as part of the antenna. When disguised as a logo, it may be more acceptable to place the antenna at optimal locations to obtain good coverage. In the present work...

  16. Logo Antenna for 5.8 GHz Wireless Communications

    DEFF Research Database (Denmark)

    Jørgensen, Kasper Lüthje; Jakobsen, Kaj Bjarne

    2016-01-01

    A logo antenna for the 5.8 GHz ISM band is presented. The idea behind the logo antenna is to use the company or university logo as part of the antenna. When disguised as a logo, it may be more acceptable to place the antenna at optimal locations to obtain good coverage. In the present work...

  17. Lightning and 85-GHz MCSs in the Global Tropics

    Science.gov (United States)

    Toracinta, E. Richard; Zipser, E. J.

    1999-01-01

    Numerous observations of tropical convection show that tropical continental mesoscale convective systems (MCSs) are much more prolific lightning producers than their oceanic counterparts. Satellite-based climatologies using 85-GHz passive microwave ice-scattering signatures from the Special Sensor Microwave/Imager (SSM/I) indicate that MCSs of various size and intensity are found throughout the global tropics. In contrast, global lightning distributions show a strong land bias with an order of magnitude difference between land and ocean lightning. This is somewhat puzzling, since 85-GHz ice-scattering and the charge separation processes that lead to lightning are both thought to depend upon the existence of large graupel particles. The fact that low 85-GHz brightness temperatures are observed in tropical oceanic MCSs containing virtually no lightning leads to the postulate that tropical oceanic and tropical continental MCSs have fundamentally different hydrometeor profiles through the mixed phase region of the cloud (0 C Lightning Imaging Sensor (LIS), and the first space-borne radar, facilitates high-resolution case studies of MCS structure throughout the global tropics. An important precursor, however, is to better understand the distribution of MCSs and lightning in the tropics. With that objective in mind, this research undertakes a systematic comparison of 85-GHz-defined MCSs and lightning over the global tropics for a full year, as an initial step toward quantifying differences between land and ocean convective systems.

  18. A 60-GHz rectenna for monolithic wireless sensor tags

    NARCIS (Netherlands)

    Gao, H.; Johannsen, U.; Matters - Kammerer, M.; Milosevic, D.; Smolders, A.B.; Roermund, van A.H.M.; Baltus, P.G.M.

    2013-01-01

    This paper presents the design of a 60-GHz rectenna with an on-chip antenna and rectifier in 65nm CMOS technology. The rectenna is often the bottleneck in realizing a fully-integrated monolithic wireless sensor tag. In this paper, problems of the mm-wave rectifier are discussed, and the

  19. Wearable Shell Antenna for 2.4 GHz Hearing Instruments

    DEFF Research Database (Denmark)

    Ruaro, Andrea; Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2016-01-01

    A novel concept for an electrically-small on-body antenna targeted for 2.4 GHz ISM band custom in-the-ear (ITE) hearing instrument (HI) applications is introduced. The antenna is based upon a cavity-backed design in order to take advantage of the maximum volume available in the ear while providin...

  20. Design of the 1-Mw, 200-Ghz, Fom Fusion Fem

    NARCIS (Netherlands)

    Urbanus, W. H.; Best, R. W. B.; Bongers, W. A.; Vaningen, A. M.; Manintveld, P.; Sterk, A. B.; Verhoeven, A. G. A.; van der Wiel, M. J.; Caplan, M.; Bratman, V. L.; Denisov, G. G.; Varfolomeev, A. A.; Khlebnikov, A. S.

    1993-01-01

    The FOM Institute for Plasma Physics has obtained funding for the development of a 1 MW, long pulse, 140-250 GHz free-electron maser. The engineering design is presently being performed in an international collaboration. In this paper the main components of the free-electron maser, the electron beam

  1. 47 CFR 15.251 - Operation within the bands 2.9-3.26 GHz, 3.267-3.332 GHz, 3.339-3.3458 GHz, and 3.358-3.6 GHz.

    Science.gov (United States)

    2010-10-01

    ... exceed 3000 microvolts/meter/MHz at 3 meters in any direction. Further, an AVIS, when in its operating position, shall not produce a field strength greater than 400 microvolts/meter/MHz at 3 meters in any... maximum of 100 microvolts/meter/MHz at 3 meters, measured from 30 MHz to 20 GHz for the complete system...

  2. Elements of a realistic 17 GHz FEL/TBA design

    International Nuclear Information System (INIS)

    Hopkins, D.B.; Halbach, K.; Hoyer, E.H.; Sessler, A.M.; Sternbach, E.J.

    1989-01-01

    Recently, renewed interest in an FEL version of a two-beam accelerator (TBA) has prompted a study of practical system and structure designs for achieving the specified physics goals. This paper presents elements of a realistic design for an FEL/TBA suitable for a 1 TeV, 17 GHz linear collider. 13 refs., 8 figs., 2 tabs

  3. Microscopic investigation of RF surfaces of 3 GHz niobium accelerator cavities following RF processing

    International Nuclear Information System (INIS)

    Graber, J.; Barnes, P.; Flynn, T.; Kirchgessner, J.; Knobloch, J.; Moffat, D.; Muller, H.; Padamsee, H.; Sears, J.

    1993-01-01

    RF processing of Superconducting accelerating cavities is achieved through a change in the electron field emission (FE) characteristics of the RF surface. The authors have examined the RF surfaces of several single-cell 3 GHz cavities, following RF processing, in a Scanning Electron Microscope (SEM). The RF processing sessions included both High Peak Power (P ≤ 50 kW) pulsed processing, and low power (≤ 20 W) continuous wave processing. The experimental apparatus also included a thermometer array on the cavity outer wall, allowing temperature maps to characterize the emission before and after RF processing gains. Multiple sites have been located in cavities which showed improvements in cavity behavior due to RF processing. Several SEM-located sites can be correlated with changes in thermometer signals, indicating a direct relationship between the surface site and emission reduction due to RF processing. Information gained from the SEM investigations and thermometry are used to enhance the theoretical model of RF processing

  4. Pierce-Wiggler electron beam system for 250 GHz GYRO-BWO: Final report

    International Nuclear Information System (INIS)

    Pirkle, D.R.; Alford, C.W.; Anderson, M.H.; Garcia, R.F.; Legarra, J.R.; Nordquist, A.L.

    1989-01-01

    This final report summarizes the design and performance of the VUW-8028 Pierce-Wiggler electron beam systems, which can be used to power high frequency gyro-BWO's. The operator's manual for this gyro-BWO beamstick is included as appendix A. Researchers at Lawrence Livermore National Laboratory (LLNL) are developing a gyro-BWO with a center frequency of 250 GHz, 6% bandwidth, and 10 kV peak output power. The gyro-BWO will be used to drive a free electron laser amplifier at LLNL. The electron beam requirements of the gyro-BWO application are: Small beam size, .100 inch at 2500 gauss axial magnetic field; a large fraction of the electron energy in rotational velocity; ability to vary the electrons' axial velocity easily, for electronic tuning; and low velocity spread i.e. little variation in the axial velocities of the electrons in the interaction region. 1 ref., 13 figs

  5. Electrostatic Vibration Energy Harvester Pre-charged Wirelessly at 2.45 GHz

    Science.gov (United States)

    Saddi, Z.; Takhedmit, H.; Karami, A.; Basset, P.; Cirio, L.

    2016-11-01

    This paper reports the design, fabrication and experiments of an electrostatic vibration harvester (e-VEH), pre-charged wirelessly for the first time by using an electromagnetic waves harvester at 2.4 GHz. The rectenna uses the Cockcroft-Walton voltage doubler rectifier. It is designed and optimized to operate at low power densities and provides high voltage levels: 0.5 V at 0.5 μW/cm2 and 0.8 V at 1 μW/cm2 The e-VEH uses the Bennet doubler as conditioning circuit. Experiments show 23 V voltage across the transducer terminal when the harvester is excited at 25 Hz by 1.5 g of external acceleration. An accumulated energy of 275 μJ and a maximum power of 0.4 μW are available for the load.

  6. Electrostatic vibration energy harvester with 2.4-GHz Cockcroft-Walton rectenna start-up

    Science.gov (United States)

    Takhedmit, Hakim; Saddi, Zied; Karami, Armine; Basset, Philippe; Cirio, Laurent

    2017-02-01

    In this paper, we propose the design, fabrication and experiments of a macro-scale electrostatic vibration energy harvester (e-VEH), pre-charged wirelessly for the first time with a 2.4-GHz Cockcroft-Walton rectenna. The rectenna is designed and optimized to operate at low power densities and provide high voltage levels: 0.5 V at 0.76 μW/cm2 and 1 V at 1.53 μW/cm2. The e-VEH uses a Bennet doubler as a conditioning circuit. Experiments show a 23-V voltage across the transducer terminal, when the harvester is excited at 25 Hz by 1.5 g of external acceleration. An accumulated energy of 275 μJ and a maximum available power of 0.4 μW are achieved. xml:lang="fr"

  7. Electrostatic Vibration Energy Harvester Pre-charged Wirelessly at 2.45 GHz

    International Nuclear Information System (INIS)

    Saddi, Z.; Takhedmit, H.; Basset, P.; Cirio, L.; Karami, A.

    2016-01-01

    This paper reports the design, fabrication and experiments of an electrostatic vibration harvester (e-VEH), pre-charged wirelessly for the first time by using an electromagnetic waves harvester at 2.4 GHz. The rectenna uses the Cockcroft-Walton voltage doubler rectifier. It is designed and optimized to operate at low power densities and provides high voltage levels: 0.5 V at 0.5 μW/cm 2 and 0.8 V at 1 μW/cm 2 The e-VEH uses the Bennet doubler as conditioning circuit. Experiments show 23 V voltage across the transducer terminal when the harvester is excited at 25 Hz by 1.5 g of external acceleration. An accumulated energy of 275 μJ and a maximum power of 0.4 μW are available for the load. (paper)

  8. Dynamic nuclear polarization by frequency modulation of a tunable gyrotron of 260GHz.

    Science.gov (United States)

    Yoon, Dongyoung; Soundararajan, Murari; Cuanillon, Philippe; Braunmueller, Falk; Alberti, Stefano; Ansermet, Jean-Philippe

    2016-01-01

    An increase in Dynamic Nuclear Polarization (DNP) signal intensity is obtained with a tunable gyrotron producing frequency modulation around 260GHz at power levels less than 1W. The sweep rate of frequency modulation can reach 14kHz, and its amplitude is fixed at 50MHz. In water/glycerol glassy ice doped with 40mM TEMPOL, the relative increase in the DNP enhancement was obtained as a function of frequency-sweep rate for several temperatures. A 68 % increase was obtained at 15K, thus giving a DNP enhancement of about 80. By employing λ/4 and λ/8 polarizer mirrors, we transformed the polarization of the microwave beam from linear to circular, and achieved an increase in the enhancement by a factor of about 66% for a given power. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Non-thermal effects of 94 GHz radiation on bacterial metabolism

    Science.gov (United States)

    Raitt, Brittany J.

    Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae were used to investigate the non-thermal effects of terahertz (THz) radiation exposure on bacterial cells. The THz source used was a 94 GHz (0.94 THz) Millitech Gunn Diode Oscillator with a power density of 1.3 mW/cm2. The cultures were placed in the middle sixty wells of two 96-well microplates, one serving as the experimental plate and one serving as a control. The experimental plate was placed on the radiation source for either two, eighteen, or twenty-four hours and the metabolism of the cells was measured in a spectrophotometer using the tetrazolium dye XTT. The results showed no consistent significant differences in either the growth rates or the metabolism of any of the bacterial species at this frequency and power density.

  10. Experimental Performance Comparison of 60 GHz DCM OFDM and Impulse BPSK Ultra-Wideband with Combined Optical Fibre and Wireless Transmission

    DEFF Research Database (Denmark)

    Beltrán, Marta; Jensen, Jesper Bevensee; Yu, Xianbin

    2010-01-01

    We present an experimental performance comparison of 1.44Gbps dual-carrier modulation OFDM and BPSK impulse-radio ultra-wideband in the 60GHz band with combined fibre, up to 40km, and 5m wireless transmission. Impulse-radio exhibits better dispersion tolerance requiring lower optical power....

  11. Enhancement of Ar sup 8 sup + ion beam intensity from RIKEN 18 GHz electron cyclotron resonance ion source by optimizing the magnetic field configuration

    CERN Document Server

    Higurashi, Y; Kidera, M; Kase, M; Yano, Y; Aihara, T

    2003-01-01

    We successfully produced a 1.55 emA Ar sup 8 sup + ion beam using the RIKEN 18 GHz electron cyclotron resonance ion source at a microwave power of 700 W. To produce such an intense beam, we optimized the minimum magnetic field of mirror magnetic field and plasma electrode position. (author)

  12. 37 GHz Direct-Modulation Bandwidth of Multi-Section InGaAsP/InP DBR-Laser with weakly coupled active grating section

    DEFF Research Database (Denmark)

    Kaiser, W.; Bach, L.; Reithmaier, J. P.

    2003-01-01

    37 GHz direct-modulation bandwidth could be obtained by a multi-section design with an integrated weakly coupled DBR grating. The laser shows side mode suppression ratios of 45 dB and output powers exceeding 20 mW....

  13. Analysis of coexistence between IEEE 802.15. 4, BLE and IEEE 802.11 in the 2.4 GHz ISM band

    NARCIS (Netherlands)

    Natarajan, R.; Zand, P.; Nabi, M.

    2016-01-01

    The rapid growth of the Internet-of-Things (IoT) has led to a proliferation of low-power wireless technologies. A major challenge in designing an IoT network is to achieve coexistence between different wireless technologies sharing the unlicensed 2.4 GHz ISM spectrum. Although there is significant

  14. Design and evaluation of noise suppression sheet for GHz band utilizing magneto-elastic effect

    Science.gov (United States)

    Igarashi, Toshiyuki; Kondo, Koichi; Yoshida, Shigeyoshi

    2017-12-01

    Feasibility of realizing a noise suppression sheet (NSS) coping with the low SHF band such as the 5 GHz band was investigated, which was composed of soft magnetic metal flakes dispersed in a polymer. For suppressing noises, the higher frequency one of the bimodal frequency dispersion (lower frequency one: Dispersion DII, higher frequency one: Dispersion DIII) seen in the imaginary permeability (μ″; magnetic loss component) spectrum of the NSS was aimed to utilize. Referring to the previous finding that Dispersion DIII is originated from a magneto-elastic effect, several magnetic composite sheets were prepared using various alloy flakes with different saturation magnetostriction (λs), and their frequency (fr(DIII)) and magnitude (μ″(DIII)) of Dispersion DIII were investigated. It was found that the NSS containing flakes with higher λs exhibited higher fr(DIII) and higher μ″(DIII)/μ″(DII), which was ratio of μ″(DIII) to the magnitude of Dispersion DII (μ″(DII)). The fr(DIII) for the NSS having the highest λs containing Fe-Co alloy flake reached 7.45 GHz and μ″ in the 5 GHz band was approximately twice as high as the conventional NSS containing Fe-Si-Al alloy flake. For transmission attenuation power ratio (Rtp) when an NSS was placed on a microstrip line with characteristic impedance of 50 Ω, NSS with larger fr(DIII)2 · μ″(DIII) ∝ Ms2 (Ms: saturation magnetization), which theoretically gave the frequency limit of imaginary permeability for a thin film, exhibited larger Rtp in the low SHF band. These results suggested that an NSS containing a magnetic flake material with both large λs and Ms was suitable for suppressing low SHF band noises.

  15. Lunar Reconnaissance Orbiter K-Band (26 GHz) Signal Analysis: Initial Study Results

    Science.gov (United States)

    Morabito, D. D.; Heckman, D.

    2017-11-01

    Lower frequency telemetry bands are becoming more limited in bandwidth due to increased competition between flight projects and other entities. Higher frequency bands offer significantly more bandwidth and hence the prospect of much higher data rates. Future or prospective flight projects considering higher frequency bands such as Ka-band (32 GHz) for deep-space and K-band (26 GHz) for near-Earth telemetry links are interested in past flight experience with available received data at these frequencies. Given that there is increased degradation due to the atmosphere at these higher frequencies, there is an effort to retrieve flight data of received signal strength to analyze performance under a variety of factors. Such factors include elevation angle, season, and atmospheric conditions. This article reports on the analysis findings of over 10 million observations of received signal strength of the Lunar Reconnaissance Orbiter (LRO) spacecraft collected between 2014 and 2017. We analyzed these data to characterize link performance over a wide range of weather conditions, season, and as a function of elevation angle. Based on this analysis, we have confirmed the safety of using a 3-dB margin for preflight planning purposes. These results suggest that a 3-dB margin with respect to adverse conditions will ensure a 98 to 99 percent data return under 95 percent weather conditions at 26 GHz (K-band), thus confirming expectations from link budget predictions. The results suggest that this margin should be applicable for all elevation angles above 10 deg. Thus, missions that have sufficient power for their desired data rates may opt to use 10 deg as their minimum elevation angle. Limitations of this study include climate variability and the fact that the observations require removal of hotbody noise in order to perform an adequate cumulative distribution function (CDF) analysis, which is planned for a future comprehensive study. Flight projects may use other link margins

  16. Cold test of cylindrical open resonator for 42 GHz, 200 kW gyrotron

    Indian Academy of Sciences (India)

    particular quality factor for TE mode at the frequency 42 GHz. The perturbation tech ... frequency 42 GHz. The good agreement ... see its performance before the final assembly of the device. This paper .... theoretical work was found. The results ...

  17. A SiGe BiCMOS double-balanced mixer with active balun for X-band Doppler radar

    DEFF Research Database (Denmark)

    Michaelsen, Rasmus S.; Johansen, Tom K.; Tamborg, Kjeld M.

    2015-01-01

    and a miniaturized Marchand balun on the LO port. Experimental results shows a conversion gain of +4 dB at 10.5 GHz with an LO drive level of 15 dBm. The LO-IF and RF-IF isolation is better than 36 dB and 26 dB, respectively, in the entire band of operation. The input referred 1 dB compression point is better than...... -11 dBm. The IIP2 is +13 dBm at a supply voltage of 3 V and +16.5 dBm at a supply voltage of 6 V. The measured noise figure is found to be ~6.5 dB at 10.5 GHz....

  18. Penerapan Metode Monte-Carlo untuk Analisis Toleransi Perubahan Nilai Komponen Terhadap Kinerja Osilator Frekuensi 2,3 GHz

    Directory of Open Access Journals (Sweden)

    Teguh Firmansyah

    2017-01-01

    Full Text Available In telecommunications equipment, an oscillator has a function to generate a carrier signal. As the carrier signal, a high stability performance is required. The frequency shift caused by component tolerances. In this research, a Monte-Carlo method was used to analyze a component tolerance on the performance of the oscillator at a frequency 2.3 GHz. A simulation was performed by software Advance Design System (ADS. In this research, the iterations were carried out as many as 212 times with tolerance component values by 10%. The analyzed performance consists of a fundamental frequency shift, a phase noise, the value of power fundamental, and a harmonic power. Meanwhile, the oscillator has a structure of bias BJT common base-bias BFR183 with Vcc = 20 V, Vce = 8.2 V and Ic = 15 mA and a dielectric resonator as a resonator. The oscillator has a fundamental frequency 2.3 GHz, phase noise -135.6 dBc / Hz, power fundamental 10.8 dBm, and harmonic power -11.2 dBm. The simulation results showed that the oscillator has a good performance with a high degree of stability on a fundamental frequency by 73%, stability phase noise 100%, stability power fundamental 64%, and stability harmonic power 61%. This simulation has a confidence level of 95.4%, an error ± 3%, and the estimation accuracy 95%.

  19. EBT-S 28-GHz, 200-kW, CW, mixed-mode, quasi-optical plasma heating system

    International Nuclear Information System (INIS)

    White, T.L.; Kimrey, H.D.; Bigelow, T.S.; Bates, D.D.; Eason, H.O.

    1984-07-01

    The ELMO Bumpy Torus-Scale (EBT-S) 28-GHz, 200-kW, cw, plasma heating system consists of a gyrotron oscillator, an oversized waveguide two-bend transmission system, and a quasi-optical mixed-mode microwave distribution manifold that feeds microwave power to the 24 plasma loads of the EBT-S fusion experiment. Balancing power to the 24 loads of the EBT-S fusion experiment. Balancing power to the 24 loads was achieved by adjusting the areas at 24 coupling irises. System performance is easily measured using system calorimetry. The distribution manifold mixed-mode power transmission, reflection, and loss coefficients are 89%, 6%, and 5%, respectively. The overall system efficiency (plasma power/gyrotron power) is 80%, but with some modifications to the distribution manifold we believe the ultimate efficiency can approach 90%. The system reliability is outstanding with a world's record 1 x 10 5 kW h of 28-GHz energy delivered to the EBT-S device with well over 1 x 10 3 operating hours

  20. Design of a 3.7 GHz oscillator for the solid state drive of the LHCD system

    International Nuclear Information System (INIS)

    Sainkar, Sandeep; Dixit, Harish; Cheeran, Alice; Sharma, P.K.

    2017-01-01

    The LHCD system is commissioned on the SST-1 tokamak for the current drive. It has a capability to generate power of 2 MW CW at 3.7 GHz and deliver the power to the tokamak via a grill antenna through a phased array of wave guides. The system relies on 4 Klystrons (TH-2103D) each generating 500 kW CW power. The klystrons act as an amplifier providing a gain of 40 dB with a bandwidth of 10 MHz and amplify the input power provided by a solid state driver. The klystron requires a supply of 65 kV and 20A for its operation and has to be extensively conditioned before it can be operated even for obtaining lower power levels. This paper describes the design of oscillator for this system. The oscillator is based on bipolar junction transistor BFR360F. Linear and non-linear analysis has been performed on the design to ascertain its performance. The oscillator delivered a power of 20 mW at 3.7 GHz

  1. Development program for a 200 kW, CW, 28 GHz gyroklystron. Final report, April 1976-September 1980

    International Nuclear Information System (INIS)

    Shively, J.; Conner, C.; Evans, S.

    1980-01-01

    The objective of this program was to develop a microwave amplifier or oscillator capable of producing 200 kW, CW power output at 28 GHz. The use of the gyrotron or cyclotron resonance interaction was pursued. A room temperature hollow core solenoid magnet with an iron case was designed to produce the magnetic field required for electron cyclotron resonance. Three pulsed gyroklystron amplifiers were built providing increasing stable output powers of 6, 65 and 76 kW. A back-up pulsed gyrotron oscillator produced 248 kW. A ceramic cone broadband water load was developed. Tests are described for the various tubes that were developed

  2. Design concepts and performance tests of the 60 GHz electron cyclotron heating (ECH) system for the JFT-2M tokamak

    International Nuclear Information System (INIS)

    Hoshino, Katsumichi; Yamamoto, Takumi; Kawashima, Hisato; Shibata, Takatoshi; Shibuya, Toshihiro

    1985-11-01

    60 GHz overmoded microwave launch system for the JFT-2M tokamak is described. The basic design concepts, specifications of each microwave component and the results of the performance tests are reported. The transmission of the microwave power is done in the circular TE 01 mode which has a low loss along the overmoded circular transmission components of 33 m in length. The microwave power of 80 - 90 kW, pulse width 100 ms in the circular TE 11 mode is finally launched into the JFT-2M tokamak plasma. (author)

  3. Design of a broadband passive X-band double-balanced mixer in SiGe HBT technology

    DEFF Research Database (Denmark)

    Michaelsen, Rasmus Schandorph; Johansen, Tom Keinicke; Tamborg, Kjeld M.

    2014-01-01

    ) and the radio frequency (RF) port. A break out of the Marchand balun is measured. This demonstrates good phase and magnitude match of 0.7° and 0.11 dB, respectively. The Marchand baluns are broadband with a measured 3 dB bandwidth of 6.4 GHz, while still having a magnitude imbalance better than 0.4 d...... frequency of 8.5 GHz is −9.8 dB at an LO drive level of 15 dBm. The whole mixer is very broadband with 3 dB bandwidth from 7 to 12 GHz covering the entire X-band. The LO–IF, RF–IF, and RF–LO isolation is better than 46, 36, and 36 dB, respectively, in the entire band of operation.......B and a phase imbalance better than 5°. Unfortunately with a rather high loss of 2.5 dB, mainly due to the low Q-factor of the inductors used. The mixer is optimized for use in doppler radars and is highly linear with a 1 dB compression point above 12 dBm IIP2 of 66 dBm. The conversion gain at the center...

  4. Computational dosimetry in embryos exposed to electromagnetic plane waves over the frequency range of 10 MHz-1.5 GHz

    International Nuclear Information System (INIS)

    Kawai, Hiroki; Nagaoka, Tomoaki; Watanabe, Soichi; Saito, Kazuyuki; Takahashi, Masaharu; Ito, Koichi

    2010-01-01

    This paper presents calculated specific absorption rate (SAR) dosimetry in 4 and 8 week Japanese pregnant-woman models exposed to plane waves over the frequency range of 10 MHz-1.5 GHz. Two types of 2 mm spatial-resolution pregnant-woman models comprised a woman model, which is similar to the average-sized Japanese adult female in height and weight, with a cubic (4 week) embryo or spheroidal (8 week) one. The averaged SAR in the embryos exposed to vertically and horizontally polarized plane waves at four kinds of propagation directions are calculated from 10 MHz to 1.5 GHz. The results indicate that the maximum average SAR in the embryos exposed to plane waves is lower than 0.08 W kg -1 when the incident power density is at the reference level of ICNIRP guideline for general public environment. (note)

  5. Design and simulation of a {approx}390 GHz seventh harmonic gyrotron using a large orbit electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Li Fengping; He Wenlong; Cross, Adrian W; Donaldson, Craig R; Zhang Liang; Phelps, Alan D R; Ronald, Kevin, E-mail: Fengping.li@strath.ac.u [SUPA, Department of Physics, University of Strathclyde, Glasgow, G4 0NG (United Kingdom)

    2010-04-21

    A {approx}390 GHz harmonic gyrotron based on a cusp electron gun has been designed and numerically modelled. The gyrotron operates at the seventh harmonic of the electron cyclotron frequency with the beam interacting with a TE{sub 71} waveguide mode. Theoretical as well as numerical simulation results using the 3D particle-in-cell code MAGIC are presented. The cusp gun generated an axis-encircling, annular shaped electron beam of energy 40 keV, current 1.5 A with a velocity ratio {alpha} of 3. Smooth cylindrical waveguides have been studied as the interaction cavities and their cavity Q optimized for 390 GHz operation. In the simulations {approx}600 W of output power at the design frequency has been demonstrated.

  6. A 65 nm CMOS high efficiency 50 GHz VCO with regard to the coupling effect of inductors

    International Nuclear Information System (INIS)

    Ye Yu; Tian Tong

    2013-01-01

    A 50 GHz cross-coupled voltage controlled oscillator (VCO) considering the coupling effect of inductors based on a 65 nm standard complementary metal oxide semiconductor (CMOS) technology is reported. A pair of inductors has been fabricated, measured and analyzed to characterize the coupling effects of adjacent inductors. The results are then implemented to accurately evaluate the VCO's LC tank. By optimizing the tank voltage swing and the buffer's operation region, the VCO achieves a maximum efficiency of 11.4% by generating an average output power of 2.5 dBm while only consuming 19.7 mW (including buffers). The VCO exhibits a phase noise of −87 dBc/Hz at 1 MHz offset, leading to a figure of merit (FoM) of −167.5 dB/Hz and a tuning range of 3.8% (from 48.98 to 50.88 GHz). (semiconductor integrated circuits)

  7. The effect of fluorine in low thermal budget polysilicon emitters for SiGe heterojunction bipolar transistors

    International Nuclear Information System (INIS)

    Schiz, F.J.W.

    1999-03-01

    results are explained by the different evolution of defects in as-deposited α-Si and p-Si. The application of fluorine in low thermal budget polysilicon emitters is demonstrated ill a novel self-aligned SiGe heterojunction bipolar transistor concept which is implemented using selective and non-selective epitaxy. The process has the advantage of layer growth ill a single epitaxy step, no growth interfaces in the depletion regions, and oxide isolation as all intrinsic part of the device structure. The device electrical results demonstrate the feasibility of the transistor concept. A detailed analysis of leakage currents is performed and a correlation made with cross-section TEM micrographs. It is shown that E/C leakage is due to punch through at the perimeter of the transistor where the SiGe base is thinner. E/B is explained by the penetration of the E/B depletion region into the extrinsic at the perimeter of the emitter. By directing the extrinsic base implant into single crystal material at the perimeter of the base, both leakage mechanisms can be avoided. (author)

  8. Effect of Si/Ge ratio on resistivity and thermopower in Gd{sub 5}Si{sub x}Ge{sub 4-x} magnetocaloric compounds

    Energy Technology Data Exchange (ETDEWEB)

    Raj Kumar, D.M. [Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad 500058 (India); Manivel Raja, M., E-mail: mraja@dmrl.drdo.i [Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad 500058 (India); Prabahar, K.; Chandrasekaran, V. [Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad 500058 (India); Poddar, Asok; Ranganathan, R. [Saha Institute of Nuclear Physics, Kolkata 700064 (India); Suresh, K.G. [Indian Institute of Technology Bombay, Mumbai 400076 (India)

    2011-07-15

    The effect of Si/Ge ratio on resistivity and thermopower behavior has been investigated in the magnetocaloric ferromagnetic Gd{sub 5}Si{sub x}Ge{sub 4-x} compounds with x=1.7-2.3. Microstructural studies reveal the presence of Gd{sub 5}(Si,Ge){sub 4}-matrix phase (5:4-type) along with traces of secondary phases (5:5 or 5:3-type). The x=1.7 and 2.0 samples display the presence of a first order structural transition from orthorhombic to monoclinic phase followed by a magnetic transition of the monoclinic phase. The alloys with x=2.2 and 2.3 display only magnetic transitions of the orthorhombic phase. A low temperature feature apparent in the AC susceptibility and resistivity data below 100 K reflects an antiferromagnetic transition of secondary phase(s) present in these compounds. The resistivity behavior study correlates with microstructural studies. A large change in thermopower of -8 {mu}V/K was obtained at the magneto-structural transition for the x=2 compound. - Research highlights: Effect of Si/Ge ratio on microstructure, magneto-structural transitions, resistivity ({rho}) and thermopower S(T) behaviour has been investigated in Gd{sub 5}Si{sub x}Ge{sub 4-x} compounds with x=1.7, 2.0, 2.2 and 2.3. Microstructural studies reveal the presence of a Gd{sub 5}(Si,Ge){sub 4} -matrix phase (5:4-type) along with traces of secondary phases (5:5 or 5:3-type). The resistivity behaviour has shown good correlation with the microstructural studies. A large change in thermopower of -8{mu}V/K was obtained at the magneto-structural transition for the x=2 compound. The resistivity and change in thermopower values were high for the alloys with Si/Ge ratio {<=}1 compared to that of the alloys with Si/Ge ratio >1.

  9. Capas de SiGe policristalino hidrogenado y su aplicación en transistores de película delgada

    Directory of Open Access Journals (Sweden)

    Rodríguez, A.

    2004-04-01

    Full Text Available The hydrogenation of polycrystalline SiGe layers, obtained by solid phase crystallization, by an electron ciclotron resonance hydrogen plasma and the influence of this hydrogenation process on the electrical characteristics of thin film transistors fabricated using this material as active layer have been studied. The hydrogenation processes were carried out at 150 and 250 ºC for several times, up to 11 hours. Infrared transmission spectra of these samples show only the absorption bands corresponding to Si-H bonds, indicating that hydrogen atoms are bonded mainly to silicon atoms. Ultraviolet reflectance measurements show that the surface damage caused by the plasma exposure increases as the Ge content of the film does. The transistors fabricated using polycrystalline SiGe films as active layer show a degradation phenomenon, consisting of a progressive decrease of the drain current at constant gate and drain bias. The degradation slows down as the hydrogenation time increases at constant temperature.

    En este trabajo se ha caracterizado el proceso de hidrogenación en un plasma generado por resonancia ciclotrónica de electrones de capas de SiGe policristalino obtenidas mediante cristalización en fase sólida y el efecto de la hidrogenación en las características eléctricas de transistores de película delgada fabricados usando dicho material. Los procesos de hidrogenación se realizaron a 150 y 250 ºC, con duraciones de hasta 11 horas. Los espectros de transmitancia en infrarrojo muestran solamente las bandas de absorción características de los enlaces Si-H. Estas bandas indican que el hidrógeno se incorpora al material enlazándose principalmente con los átomos de silicio. Las medidas de reflectancia en el ultravioleta indican que se crea daño en la superficie de la muestra y que éste aumenta a medida que lo hace el contenido en Ge. Los transistores de película delgada con capa activa de SiGe policristalino muestran un fen

  10. Si/SiGe heterointerfaces in one-, two-, and three-dimensional nanostructures: their impact on SiGe light emission

    Science.gov (United States)

    Lockwood, David; Wu, Xiaohua; Baribeau, Jean-Marc; Mala, Selina; Wang, Xialou; Tsybeskov, Leonid

    2016-03-01

    Fast optical interconnects together with an associated light emitter that are both compatible with conventional Si-based complementary metal-oxide- semiconductor (CMOS) integrated circuit technology is an unavoidable requirement for the next-generation microprocessors and computers. Self-assembled Si/Si1-xGex nanostructures, which can emit light at wavelengths within the important optical communication wavelength range of 1.3 - 1.55 μm, are already compatible with standard CMOS practices. However, the expected long carrier radiative lifetimes observed to date in Si and Si/Si1-xGex nanostructures have prevented the attainment of efficient light-emitting devices including the desired lasers. Thus, the engineering of Si/Si1-xGex heterostructures having a controlled composition and sharp interfaces is crucial for producing the requisite fast and efficient photoluminescence (PL) at energies in the range 0.8-0.9 eV. In this paper we assess how the nature of the interfaces between SiGe nanostructures and Si in heterostructures strongly affects carrier mobility and recombination for physical confinement in three dimensions (corresponding to the case of quantum dots), two dimensions (corresponding to quantum wires), and one dimension (corresponding to quantum wells). The interface sharpness is influenced by many factors such as growth conditions, strain, and thermal processing, which in practice can make it difficult to attain the ideal structures required. This is certainly the case for nanostructure confinement in one dimension. However, we demonstrate that axial Si/Ge nanowire (NW) heterojunctions (HJs) with a Si/Ge NW diameter in the range 50 - 120 nm produce a clear PL signal associated with band-to-band electron-hole recombination at the NW HJ that is attributed to a specific interfacial SiGe alloy composition. For three-dimensional confinement, the experiments outlined here show that two quite different Si1-xGex nanostructures incorporated into a Si0.6Ge0.4 wavy

  11. A 5.2/5.8 GHz Dual Band On-Off Keying Transmitter Design for Bio-Signal Transmission

    Science.gov (United States)

    Wu, Chang-Hsi; You, Hong-Cheng; Huang, Shun-Zhao

    2018-02-01

    An architecture of 5.2/5.8-GHz dual-band on-off keying (DBOOK) modulated transmitter is designed in a 0.18-μm CMOS technology. The proposed DBOOK transmitter is used in the biosignal transmission system with high power efficiency and small area. To reduce power consumption and enhance output swing, two pairs of center-tapped transformers are used as both LC tank and source grounding choke for the designed voltage controlled oscillator (VCO). Switching capacitances are used to achieve dual band operations, and a complemented power combiner is used to merge the differential output power of VCO to a single-ended output. Besides, the linearizer circuits are used in the proposed power amplifier with wideband output matching to improve the linearity both at 5.2/5.8-GHz bands. The designed DBOOK transmitter is implemented by dividing it into two chips. One chip implements the dual-band switching VCO and power combiner, and the other chip implements a linear power amplifier including dual-band operation. The first chip drives an output power of 2.2mW with consuming power of 5.13 mW from 1.1 V supply voltage. With the chip size including pad of 0.61 × 0.91 m2, the measured data rate and transmission efficiency attained are 100 Mb/s and 51 pJ/bit, respectively. The second chip, for power enhanced mode, exhibits P1 dB of -9 dBm, IIP3 of 1 dBm, the output power 1 dB compression point of 12.42 dBm, OIP3 of about 21 dBm, maximum output power of 17.02/16.18 dBm, and power added efficiency of 17.13/16.95% for 5.2/ 5.8 GHz. The chip size including pads is 0:693 × 1:084mm2.

  12. Development of a thermionic magnicon amplifier at 11.4 GHz

    International Nuclear Information System (INIS)

    Gold, S.H.; Hafizi, B.; Fliflet, A.W.; Kinkead, A.K.; True, R.

    1997-01-01

    The magnicon is a scanning-beam microwave amplifier tube that is being developed as an rf source for the proposed TeV Next Linear Collider. In it, a solid electron beam is spun up to high transverse momentum in a series of deflection cavities containing synchronously rotating TM modes, and then spun down again in an output cavity whose mode is synchronous with that of the deflection cavities. A recent magnicon experiment at NRL, using a ∼ 650 kV, 225 A, 5.5-mm-diam. electron beam produced from a cold cathode driven by a single-shot Marx generator, demonstrated 14 MW (±3 dB) at 11.12 GHz with 105 efficiency in the synchronous magnicon mode, but was limited by plasma loading in the deflection cavities to a regime in which the last cavity of the deflection system (the penultimate cavity) was unstable. A new 11.4 GHz rep-rated thermionic magnicon experiment is being assembled, using an advanced ultra-high-convergence electron gun driven by a 10 Hz, 1.5 microsecond modulator top produce a 500 kV, 210 A, 2-mm diameter electron beam. The magnicon circuit has been optimized for minimum surface rf fields and maximum efficiency, and will be engineered for high temperature bakeout and high vacuum operation. This experiment should begin operation in the Summer of 1997. The predicted power is 60 MW at ∼ 60% efficiency

  13. Ray-Based Statistical Propagation Modeling for Indoor Corridor Scenarios at 15 GHz

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2016-01-01

    Full Text Available According to the demands for fifth-generation (5G communication systems, high frequency bands (above 6 GHz need to be adopted to provide additional spectrum. This paper investigates the characteristics of indoor corridor channels at 15 GHz. Channel measurements with a vector network analyzer in two corridors were conducted. Based on a ray-optical approach, a deterministic channel model covering both antenna and propagation characteristic is presented. The channel model is evaluated by comparing simulated results of received power and root mean square delay spread with the corresponding measurements. By removing the impact of directional antennas from the transmitter and receiver, a path loss model as well as small-scale fading properties for typical corridors is presented based on the generated samples from the deterministic model. Results show that the standard deviation of path loss variation is related to the Tx height, and placing the Tx closer to the ceiling leads to a smaller fluctuation of path loss.

  14. A dual-mode 6-9 GHz transmitter for OFDM-UWB

    International Nuclear Information System (INIS)

    Chen Yunfeng; Gao Ting; Li Wei; Li Ning; Ren Junyan

    2011-01-01

    This paper presents a fully integrated dual-mode 6 to 9 GHz transmitter for both WiMedia and China MB-OFDM UWB applications. The proposed transmitter consists of a dual-mode I/QLPF, an up-conversion mixer, a two-stage power driver amplifier and a broadband high-speed frequency divider with LO buffers for I/Q LO carrier generation. The measurement results show that the gain ripple of the transmitter is within ±1.5/±2.8 dB from 6 to 8.7/9 GHz. The output IP3 is about +13.2 dBm, the output 1dBCP is around +2.8 dBm, and the LO leakage/sideband rejection ratio is about -35/-38 dBc. The ESD protected chip is fabricated with a TSMC 0.13 μm RFCMOS process with a die size of 1.6 x 1.3 mm 2 and the core circuit consumes only 46 mA under a 1.2 V supply. (semiconductor integrated circuits)

  15. A dual-mode 6-9 GHz transmitter for OFDM-UWB

    Energy Technology Data Exchange (ETDEWEB)

    Chen Yunfeng; Gao Ting; Li Wei; Li Ning; Ren Junyan, E-mail: jyren@fudan.edu.cn, E-mail: w-li@fudan.edu.cn [State Key Laboratory of ASIC and System, Fudan University, Shanghai 201203 (China)

    2011-05-15

    This paper presents a fully integrated dual-mode 6 to 9 GHz transmitter for both WiMedia and China MB-OFDM UWB applications. The proposed transmitter consists of a dual-mode I/QLPF, an up-conversion mixer, a two-stage power driver amplifier and a broadband high-speed frequency divider with LO buffers for I/Q LO carrier generation. The measurement results show that the gain ripple of the transmitter is within {+-}1.5/{+-}2.8 dB from 6 to 8.7/9 GHz. The output IP3 is about +13.2 dBm, the output 1dBCP is around +2.8 dBm, and the LO leakage/sideband rejection ratio is about -35/-38 dBc. The ESD protected chip is fabricated with a TSMC 0.13 {mu}m RFCMOS process with a die size of 1.6 x 1.3 mm{sup 2} and the core circuit consumes only 46 mA under a 1.2 V supply. (semiconductor integrated circuits)

  16. Measurements by a Vector Network Analyzer at 325 to 508 GHz

    Science.gov (United States)

    Fung, King Man; Samoska, Lorene; Chattopadhyay, Goutam; Gaier, Todd; Kangaslahti, Pekka; Pukala, David; Lau, Yuenie; Oleson, Charles; Denning, Anthony

    2008-01-01

    Recent experiments were performed in which return loss and insertion loss of waveguide test assemblies in the frequency range from 325 to 508 GHz were measured by use of a swept-frequency two-port vector network analyzer (VNA) test set. The experiments were part of a continuing effort to develop means of characterizing passive and active electronic components and systems operating at ever increasing frequencies. The waveguide test assemblies comprised WR-2.2 end sections collinear with WR-3.3 middle sections. The test set, assembled from commercially available components, included a 50-GHz VNA scattering- parameter test set and external signal synthesizers, augmented with recently developed frequency extenders, and further augmented with attenuators and amplifiers as needed to adjust radiofrequency and intermediate-frequency power levels between the aforementioned components. The tests included line-reflect-line calibration procedures, using WR-2.2 waveguide shims as the "line" standards and waveguide flange short circuits as the "reflect" standards. Calibrated dynamic ranges somewhat greater than about 20 dB for return loss and 35 dB for insertion loss were achieved. The measurement data of the test assemblies were found to substantially agree with results of computational simulations.

  17. Measurements of the cosmic microwave background temperature at 1.47 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Bensadoun, Marc John [Univ. of California, Berkeley, CA (United States)

    1991-11-01

    A radiofrequency-gain total power radiometer measured the intensity of the cosmic microwave background (CMB) at a frequency of 1.47 GHz (20.4 cm wavelength) from White Mountain, California, in September 1988 and from the South Pole, Antarctica, in December 1989. The CMB thermodynamic temperature, TCMB, is 2.27 ± 0.25 K (68% C.L.) measured from White Mountain and 2.26 ± 0.21 K from the South Pole site. The combined result is 2.27 ± 0.19 K. The correction for galactic emission has been derived from scaled low-frequency maps and constitutes the main source, of error. The atmospheric signal is found by extrapolation from zenith scan measurements at higher frequencies. The result is consistent with previous low-frequency measurements, including a measurement at 1.41 GHz (Levin et al. 1988) made with an earlier version of this instrument. The result is ~2.5 σ (~l% probability) from the 2.74 ± 0.02,K global average CMB temperature.

  18. Measurements of the cosmic microwave background temperature at 1. 47 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Bensadoun, M.J.

    1991-11-01

    A radiofrequency-gain total power radiometer measured the intensity of the cosmic microwave background (CMB) at a frequency of 1.47 GHz (20.4 cm wavelength) from White Mountain, California, in September 1988 and from the South Pole, Antarctica, in December 1989. The CMB thermodynamic temperature, TCMB, is 2.27 {plus minus} 0.25 K (68% C.L.) measured from White Mountain and 2.26 {plus minus} 0.21 K from the South Pole site. The combined result is 2.27 {plus minus} 0.19 K. The correction for galactic emission has been derived from scaled low-frequency maps and constitutes the main source, of error. The atmospheric signal is found by extrapolation from zenith scan measurements at higher frequencies. The result is consistent with previous low-frequency measurements, including a measurement at 1.41 GHz (Levin et al. 1988) made with an earlier version of this instrument. The result is {approximately}2.5 {sigma} ({approximately}l% probability) from the 2.74 {plus minus} 0.02,K global average CMB temperature.

  19. Gallium Nitride MMICs for mm-Wave Power Operation

    NARCIS (Netherlands)

    Quay, R.; Maroldt, S.; Haupt, C.; Heijningen, M. van; Tessmann, A.

    2009-01-01

    In this paper a Gallium Nitride MMIC technology for high-power amplifiers between 27 GHz and 101 GHz based on 150 nm- and 100 nm-gate technologies is presented. The GaN HEMT MMICs are designed using coplanar waveguide transmission-line-technology on 3-inch semi-insulating SiC substrates. The

  20. T25 ITER ECH window development 110 GHz ECH distributed window development. Final report, May 1, 1994 - December 31, 1995

    International Nuclear Information System (INIS)

    Olstad, R.A.; Moeller, C.P.; Grunloh, H.J.

    1998-01-01

    Electron Cyclotron Heating (ECH) is one of the major candidates for Heating and Current Drive on ITER. ECH is extremely attractive from a reactor engineering point of view, offering compact launch structures, high injected power density, and a simple interface with the shield/blanket. Economic deployment of ECH for ITER requires MW unit microwave sources (gyrotrons). The present technology limitation is the availability of suitable low loss output windows. These are needed for the torus as well as the tube. The torus window, in particular, is a demanding application as it also serves as a tritium barrier. Several distinct window concepts are under development by the various Parties. This report summarizes the efforts to make and test a open-quotes distributedclose quotes window suitable for 1 MW cw operation at 110 GHz. A companion report (Final Report on Task 245+) describes the efforts to make a distributed window suitable for 1 MW cw operation at 170 GHz, the main frequency of interest to ITER. General Atomics (GA) fabricated a 4 in. x 4 in. 110 GHz distributed window which was delivered in September 1995 to Communications and Power Industries (CPI). Hot tests at CPI confirmed the power handling capability of the window. Tests were conducted with a reduced beam size at 200 kW with 0.7 s pulses without any arcing or excessive window temperatures. The power density and pulse length were equivalent to that in a full size 1.2 MW CW beam with a peak-to-average power ratio of 2.7. This window was assembled using a gold braze material to bond the sapphire strips to the niobium frame. The braze was successful except for small leaks at two locations, and re-braze efforts were unsuccessful