Theoretical and experimental study of microstrip-to-slot line uniplanar transition

Science.gov (United States)

Yook, Jong-Gwan; Dib, Nihad I.; Katehi, Linda P. B.; Simons, Rainee N.; Taub, Susan R.

1994-05-01

Recent advances in MMCI technology make it possible to construct transitions from CPW-to-microstrip with via hole, microstrip-to-slot line and microshield line-to-CPW all of which have potential applications in the feed network of antennas. In this study we investigate the characteristics of the microstrip-to-slot line uniplanar transition using the finite element methods (FEM) and finite difference time domain (FDTD) techniques, and compared the theoretical results with the measurements. In both cases, the results agree with the measurements within a few percent.

A gas microstrip X-ray detector for soft energy fluorescence EXAFS

CERN Document Server

Smith, A D; Derbyshire, G E; Duxbury, D M; Lipp, J; Spill, E J; Stephenson, R

2001-01-01

Gas microstrip detectors have been previously developed by the particle physics community, where their robustness, compactness and high counting speed have been recognised. These features are particularly attractive to synchrotron radiation use. In this paper, we describe a gas microstrip detector employing multi-element readout and specifically developed for high count rate fluorescence EXAFS at soft X-ray energies below 4 keV.

Optical properties of polarization-dependent geometrical phase elements with partially polarized light

International Nuclear Information System (INIS)

Gorodetski, Y.; Biener, G.; Niv, A.; Kleiner, V.; Hasman, E.

2005-01-01

Full Text:The behavior of geometrical phase elements illuminated with partially polarized monochromatic beams is being theoretically as well as experimentally investigated. The element discussed in this paper is composed of wave plates with retardation and space-variant orientation angle. We found that a beam emerging from such an element comprises two polarization orders of right and left-handed circularly polarized states with conjugate geometrical phase modification. This phase equals twice the orientation angle of the space-variant wave plate comprising the element. Apart from the two polarization orders, the emerging beam coherence polarization matrix comprises a matrix termed as the vectorial interference matrix. This matrix contains the information concerning the correlation between the two orthogonal circularly polarized portions of the incident beam. In this paper we measure this correlation by a simple interference experiment. Furthermore, we found that the equivalent mutual intensity of the emerging beam is being modulated according to the geometrical phase induced by the element. Other interesting phenomena along propagation will be discussed theoretically and experimentally demonstrated. We demonstrate experimentally our analysis by using a spherical geometrical phase element, which is realized by use of space-variant sub wavelength grating and illuminated with a CO 2 laser radiation of 10.6μm wavelength

A Dual Polarization, Active, Microstrip Antenna for an Orbital Imaging Radar System Operating at L-Band

Science.gov (United States)

Kelly, Kenneth C.; Huang, John

2000-01-01

A highly successful Earth orbiting synthetic antenna aperture radar (SAR) system, known as the SIR-C mission, was carried into orbit in 1994 on a U.S. Shuttle (Space Transportation System) mission. The radar system was mounted in the cargo bay with no need to fold, or in any other way reduce the size of the antennas for launch. Weight and size were not limited for the L-Band, C-Band, and X-Band radar systems of the SIR-C radar imaging mission; the set of antennas weighed 10,500 kg, the L-Band antenna having the major share of the weight. This paper treats designing an L-Band antenna functionally similar to that used for SIR-C, but at a fraction of the cost and at a weight in the order of 250 kg. Further, the antenna must be folded to fit into the small payload shroud of low cost booster rocket systems. Over 31 square meters of antenna area is required. This low weight, foldable, electronic scanning antenna is for the proposed LightSAR radar system which is to be placed in Earth orbit on a small, dedicated space craft at the lowest possible cost for an efficient L- Band radar imaging system. This LightSAR spacecraft radar is to be continuously available for at least five operational years, and have the ability to map or repeat-map any area on earth within a few days of any request. A microstrip patch array, with microstrip transmission lines heavily employed in the aperture and in the corporate feed network, was chosen as the low cost approach for this active dual-polarization, 80 MHz (6.4%) bandwidth antenna design.

Design of a dual linear polarization antenna using split ring resonators at X-band

Science.gov (United States)

Ahmed, Sadiq; Chandra, Madhukar

2017-11-01

Dual linear polarization microstrip antenna configurations are very suitable for high-performance satellites, wireless communication and radar applications. This paper presents a new method to improve the co-cross polarization discrimination (XPD) for dual linear polarized microstrip antennas at 10 GHz. For this, three various configurations of a dual linear polarization antenna utilizing metamaterial unit cells are shown. In the first layout, the microstrip patch antenna is loaded with two pairs of spiral ring resonators, in the second model, a split ring resonator is placed between two microstrip feed lines, and in the third design, a complementary split ring resonators are etched in the ground plane. This work has two primary goals: the first is related to the addition of metamaterial unit cells to the antenna structure which permits compensation for an asymmetric current distribution flow on the microstrip antenna and thus yields a symmetrical current distribution on it. This compensation leads to an important enhancement in the XPD in comparison to a conventional dual linear polarized microstrip patch antenna. The simulation reveals an improvement of 7.9, 8.8, and 4 dB in the E and H planes for the three designs, respectively, in the XPD as compared to the conventional dual linear polarized patch antenna. The second objective of this paper is to present the characteristics and performances of the designs of the spiral ring resonator (S-RR), split ring resonator (SRR), and complementary split ring resonator (CSRR) metamaterial unit cells. The simulations are evaluated using the commercial full-wave simulator, Ansoft High-Frequency Structure Simulator (HFSS).

Dual-Frequency, Dual-Polarization Microstrip Antenna Development for High-Resolution, Airborne SAR

DEFF Research Database (Denmark)

Granholm, Johan; Skou, N.

2000-01-01

synthetic aperture radar (SAR) system. The dual-frequency array concept adopted relies on the use of probe-fed perforated, stacked patches for L-band (1.2-1.3 GHz). Inside these perforations probe-fed, wideband stacked microstrip patches for C-band (4.9-5.7 GHz) are placed. Measured impedance and radiation...

Quality assurance of the silicon microstrip sensors for the CBM experiment

Energy Technology Data Exchange (ETDEWEB)

Panasenko, Iaroslav [Physikalisches Institut, Universitaet Tuebingen (Germany); Institute for Nuclear Research, Kiev (Ukraine); Larionov, Pavel [University of Frankfurt (Germany); Collaboration: CBM-Collaboration

2016-07-01

The CBM experiment at FAIR will investigate the properties of nuclear matter at extreme conditions created in ultrarelativistic heavy-ion collisions. Its core detector - the Silicon Tracking System (STS) - will determine the momentum of charged particles from beam-target interactions. The track multiplicity will reach up to 700 within the detector aperture covering the polar angle 2.5 and 25 . High track density as well as stringent requirements to the momentum resolution (∝1%) require a system with high channel granularity and low material budget. The STS will be constructed of about 1200 double-sided silicon microstrip sensors with 58 μm pitch and a total area of ∝4 m{sup 2} with all together 2.1 million channels will be read out. In this talk the quality assurance of double-sided silicon microstrip sensors is discussed. This includes both visual and electrical characterization. For this purpose dedicated equipment has been set up in the clean rooms of the GSI Detector Laboratory and at Tuebingen University. Results of the electrical characterization of prototype microstrip sensors CBM06 are presented.

Computer-Aided Design of Microstrip GaAs Mesfet Amplifiers

DEFF Research Database (Denmark)

Nielsen, Niels Ole

1976-01-01

Results on computer-aided design of broadband GaAs MESFET amplifiers in microstrip is presented. The analysis of an amplifier is based on measured scattering parameters and a model of the microstrip structure, which includes parasitics and junction effects. The optimized performance of one stage...... amplifiers with lossless distributed matching elements is presented. Realized amplifiers are in good agreement with the theory. One stage amplifiers with a 1 ¿m FET in chip form exhibit 5.8 dB of gain in the range 8-12 GHz, while a gain of 4.5 dB from 4-8 GHz has been obtained with a packaged 1 ¿m FET....

Radial microstrip slotline feed network for circular mobile communications array

Science.gov (United States)

Simons, Rainee N.; Kelly, Eron S.; Lee, Richard Q.; Taub, Susan R.

1994-01-01

In mobile and satellite communications there is a need for low cost and low profile antennas which have a toroidal pattern. Antennas that have been developed for mobile communications include a L-Band electronically steered stripline phased array, a Ka-Band mechanically steered elliptical reflector antenna and a Ka-Band printed dipole. In addition, a L-Band mechanically steered microstrip array, a L-Band microstrip phased array tracking antenna for mounting on a car roof and an X-Band radial line slotted waveguide antenna have been demonstrated. In the above electronically scanned printed arrays, the individual element radiates normally to the plane of the array and hence require a phase shifter to scan the beam towards the horizon. Scanning in the azimuth is by mechanical or electronic steering. An alternate approach is to mount microstrip patch radiators on the surface of a cone to achieve the required elevation angle. The array then scans in the azimuth by beam switching.

Simplified microstrip discontinuity modeling using the transmission line matrix method interfaced to microwave CAD

Science.gov (United States)

Thompson, James H.; Apel, Thomas R.

1990-07-01

A technique for modeling microstrip discontinuities is presented which is derived from the transmission line matrix method of solving three-dimensional electromagnetic problems. In this technique the microstrip patch under investigation is divided into an integer number of square and half-square (triangle) subsections. An equivalent lumped-element model is calculated for each subsection. These individual models are then interconnected as dictated by the geometry of the patch. The matrix of lumped elements is then solved using either of two microwave CAD software interfaces with each port properly defined. Closed-form expressions for the lumped-element representation of the individual subsections is presented and experimentally verified through the X-band frequency range. A model demonstrating the use of symmetry and block construction of a circuit element is discussed, along with computer program development and CAD software interface.

Finite Element Analysis of Simple Rectangular Microstrip Sensor for Determination Moisture Content of Hevea Rubber Latex

Science.gov (United States)

Yahaya, NZ; Ramli, MR; Razak, NNANA; Abbas, Z.

2018-04-01

The Finite Element Method, FEM has been successfully used to model a simple rectangular microstrip sensor to determine the moisture content of Hevea rubber latex. The FEM simulation of sensor and samples was implemented by using COMSOL Multiphysics software. The simulation includes the calculation of magnitude and phase of reflection coefficient and was compared to analytical method. The results show a good agreement in finding the magnitude and phase of reflection coefficient when compared with analytical results. Field distributions of both the unloaded sensor as well as the sensor loaded with different percentages of moisture content were visualized using FEM in conjunction with COMSOL software. The higher the amount of moisture content in the sample the more the electric loops were observed.

Microstrip detector for the ALICE experiment

CERN Multimedia

Laurent Guiraud

1996-01-01

This photo shows a close up of one of the silicon microstrip detectors that will be installed on the ALICE experiment at the LHC. 1698 double-sided modules of these silicon microstrips will be installed in the two outermost layers of the ALICE inner tracking system. The microstrips have to be specially designed to withstand the high resolution levels at the heart of the detector.

5G MIMO Conformal Microstrip Antenna Design

Directory of Open Access Journals (Sweden)

Qian Wang

2017-01-01

Full Text Available With the development of wireless communication technology, 5G will develop into a new generation of wireless mobile communication systems. MIMO (multiple-input multiple-output technology is expected to be one of the key technologies in the field of 5G wireless communications. In this paper, 4 pairs of microstrip MIMO conformal antennas of 35 GHz have been designed. Eight-element microstrip Taylor antenna array with series-feeding not only achieves the deviation of the main lobe of the pattern but also increases the bandwidth of the antenna array and reduces sidelobe. MIMO antennas have been fabricated and measured. Measurement results match the simulation results well. The return loss of the antenna at 35 GHz is better than 20 dB, the first sidelobe level is −16 dB, and the angle between the main lobe and the plane of array is 60°.

A Multibeam Dual-Band Orthogonal Linearly Polarized Antenna Array for Satellite Communication on the Move

Directory of Open Access Journals (Sweden)

Yi Liu

2015-01-01

Full Text Available The design and simulation of a 10 × 8 multibeam dual-band orthogonal linearly polarized antenna array operating at Ku-band are presented for transmit-receive applications. By using patches with different coupling methods as elements, both perpendicular polarization in 12.25–12.75 GHz band and horizontal polarization in 14.0–14.5 GHz band are realized in a shared antenna aperture. A microstrip Rotman lens is employed as the beamforming network with 7 input ports, which can generate a corresponding number of beams to cover −30°–30° with 5 dB beamwidth along one dimension. This type of multibeam orthogonal linearly polarized planar antenna is a good candidate for satellite communication (SatCom.

Millimeter-Wave Microstrip Antenna Array Design and an Adaptive Algorithm for Future 5G Wireless Communication Systems

Directory of Open Access Journals (Sweden)

Cheng-Nan Hu

2016-01-01

Full Text Available This paper presents a high gain millimeter-wave (mmW low-temperature cofired ceramic (LTCC microstrip antenna array with a compact, simple, and low-profile structure. Incorporating minimum mean square error (MMSE adaptive algorithms with the proposed 64-element microstrip antenna array, the numerical investigation reveals substantial improvements in interference reduction. A prototype is presented with a simple design for mass production. As an experiment, HFSS was used to simulate an antenna with a width of 1 mm and a length of 1.23 mm, resonating at 38 GHz. Two identical mmW LTCC microstrip antenna arrays were built for measurement, and the center element was excited. The results demonstrated a return loss better than 15 dB and a peak gain higher than 6.5 dBi at frequencies of interest, which verified the feasibility of the design concept.

Frequency scanning microstrip antennas

DEFF Research Database (Denmark)

Danielsen, Magnus; Jørgensen, Rolf

1979-01-01

The principles of using radiating microstrip resonators as elements in a frequency scanning antenna array are described. The resonators are cascade-coupled. This gives a scan of the main lobe due to the phase-shift in the resonator in addition to that created by the transmission line phase......-shift. Experimental results inX-band, in good agreement with the theory, show that it is possible to scan the main lobe an angle ofpm30degby a variation of the frequencypm300MHz, and where the 3 dB beamwidth is less than10deg. The directivity was 14.7 dB, while the gain was 8.1 dB. The efficiency might be improved...

Gas microstrip chambers

International Nuclear Information System (INIS)

McIntyre, P.M.; Barasch, E.F.; Bowcock, T.J.V.; Demroff, H.P.; Elliott, S.M.; Howe, M.R.; Lee, B.; Mazumdar, T.K.; Pang, Y.; Smith, D.D.; Wahl, J.; Wu, Y.; Yue, W.K.; Gaedke, R.M.; Vanstraelen, G.

1992-01-01

The gas microstrip chamber has been developed from concept to experimental system during the past three years. A pattern of anode and grid lines are microfabricated onto a dielectric substrate and configured as a high-resolution MWPC. Four recent developments are described: Suitable plastic substrates and lithography techniques for large-area chambers; non-planar silicon-based chambers for 20 μm resolution; integrated on-board synchronous front-end electronics and data buffering; and a porous silicon active cathode for enhanced efficiency and time response. The microstrip chamber appears to be a promising technology for applications in microvertex, tracking spectrometer, muon spectrometer, and transition radiation detection. (orig.)

Signal of microstrip scanning near-field optical microscope in far- and near-field zones.

Science.gov (United States)

Morozov, Yevhenii M; Lapchuk, Anatoliy S

2016-05-01

An analytical model of interference between an electromagnetic field of fundamental quasi-TM(EH)00-mode and an electromagnetic field of background radiation at the apex of a near-field probe based on an optical plasmon microstrip line (microstrip probe) has been proposed. The condition of the occurrence of electromagnetic energy reverse flux at the apex of the microstrip probe was obtained. It has been shown that the nature of the interference depends on the length of the probe. Numerical simulation of the sample scanning process was conducted in illumination-reflection and illumination-collection modes. Results of numerical simulation have shown that interference affects the scanning signal in both modes. However, in illumination-collection mode (pure near-field mode), the signal shape and its polarity are practically insensible to probe length change; only signal amplitude (contrast) is slightly changed. However, changing the probe length strongly affects the signal amplitude and shape in the illumination-reflection mode (the signal formed in the far-field zone). Thus, we can conclude that even small background radiation can significantly influence the signal in the far-field zone and has practically no influence on a pure near-field signal.

A counting silicon microstrip detector for precision compton polarimetry

CERN Document Server

Doll, D W; Hillert, W; Krüger, H; Stammschroer, K; Wermes, N

2002-01-01

A detector for the detection of laser photons backscattered off an incident high-energy electron beam for precision Compton polarimetry in the 3.5 GeV electron stretcher ring ELSA at Bonn University has been developed using individual photon counting. The photon counting detector is based on a silicon microstrip detector system using dedicated ASIC chips. The produced hits by the pair converted Compton photons are accumulated rather than individually read out. A transverse profile displacement can be measured with mu m accuracy rendering a polarization measurement of the order of 1% on the time scale of 10-15 min possible.

Micro-strip sensors based on CVD diamond

Energy Technology Data Exchange (ETDEWEB)

Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D' Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; Mac Lynne, L.; Manfredotti, C.; Meier, D. E-mail: dirk.meier@cern.ch; Mishina, M.; Moroni, L.; Oh, A.; Pan, L.S.; Pernicka, M.; Peitz, A.; Perera, L.; Pirollo, S.; Procario, M.; Riester, J.L.; Roe, S.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Wetstein, M.; White, C.; Zeuner, W.; Zoeller, M

2000-10-11

In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition, we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation.

Micro-strip sensors based on CVD Diamond

CERN Document Server

Adam, W; Bergonzo, P; Bertuccio, G; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; D'Angelo, P; Dabrowski, W; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Hallewell, G D; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Kass, R; Koeth, T W; Krammer, Manfred; Lo Giudice, A; Lü, R; MacLynne, L; Manfredotti, C; Meier, D; Mishina, M; Moroni, L; Oh, A; Pan, L S; Pernicka, Manfred; Peitz, A; Perera, L P; Pirollo, S; Procario, M; Riester, J L; Roe, S; Rousseau, L; Rudge, A; Russ, J; Sala, S; Sampietro, M; Schnetzer, S R; Sciortino, S; Stelzer, H; Stone, R; Suter, B; Tapper, R J; Tesarek, R J; Trischuk, W; Tromson, D; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; Wetstein, M; White, C; Zeuner, W; Zoeller, M M

2000-01-01

In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation.

Micro-strip sensors based on CVD diamond

International Nuclear Information System (INIS)

Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D'Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; Mac Lynne, L.; Manfredotti, C.; Meier, D.; Mishina, M.; Moroni, L.; Oh, A.; Pan, L.S.; Pernicka, M.; Peitz, A.; Perera, L.; Pirollo, S.; Procario, M.; Riester, J.L.; Roe, S.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Wetstein, M.; White, C.; Zeuner, W.; Zoeller, M.

2000-01-01

In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition, we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation

Micro-strip sensors based on CVD diamond

Science.gov (United States)

Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D'Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; van Eijk, B.; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K. K.; Gheeraert, E.; Hallewell, G.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; mac Lynne, L.; Manfredotti, C.; Meier, D.; Mishina, M.; Moroni, L.; Oh, A.; Pan, L. S.; Pernicka, M.; Peitz, A.; Perera, L.; Pirollo, S.; Procario, M.; Riester, J. L.; Roe, S.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R. J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Walsh, A. M.; Wedenig, R.; Weilhammer, P.; Wetstein, M.; White, C.; Zeuner, W.; Zoeller, M.; RD42 Collaboration

2000-10-01

In this article we present the performance of recent chemical vapour deposition (CVD) diamond micro-strip sensors in beam tests. In addition, we present the first comparison of a CVD diamond micro-strip sensor before and after proton irradiation.

Fabrication and impact performance of three-dimensionally integrated microstrip antennas with microstrip and coaxial feeding

International Nuclear Information System (INIS)

Yao, Lan; Wang, Xin; Xu, Fujun; Zhao, Da; Jiang, Muwen; Qiu, Yiping

2009-01-01

A conformal load-bearing antenna structure (CLAS) combines the antenna into a composite structure such that it can carry the designed load while functioning as an antenna. In this paper, two types of new 3D integrated microstrip antennas (3DIMAs) with different feeding methods are designed to work at the radar L-band. Different from the conventional CLAS, the radiating patch and the ground plane of the 3DIMA are both composed of woven conductive wires and are bonded into the 3D composite physically by Z-yarns, greatly improving the damage tolerance of the antenna. The return loss of the coaxial-fed antenna is −13.15 dB with a resonant frequency of 1.872 GHz, while that of the microstrip-fed antenna is −31.50 dB with a resonant frequency of 1.33 GHz. Both of the 3DIMAs have similar radiation patterns to that of the traditionally designed microstrip antenna. In addition, an experimental investigation of the impact response of the coaxial-fed 3DIMA was carried out and the results showed the radiation pattern had almost no change even when the antenna received an impact energy of 15 J, exhibiting superior impact resistance to that of a conventional microstrip antenna

The application of a microstrip gas counter to energy-dispersive x-ray fluorescence analysis

International Nuclear Information System (INIS)

Veloso, J.F.C.A.; Santos, J.M.F. dos; Conde, C.A.N.

1996-01-01

Performance characteristics of a microstrip gas counter operated as a x-ray fluorescence spectrometer are reported. Gas amplification as a function of microstrip anode-cathode voltage was measured, and the breakdown threshold voltage was determined in pure xenon. The detector temporal stability and the effect of gas purity were assessed. Energy resolution and linearity, detection efficiency, and uniformity of spatial response in the 2- to 60-keV x-ray energy range were determined from the pulse-height distributions of the fluorescence x-ray spectra induced in a variety of single- and multi-element sample materials. Energy resolution similar to conventional proportional counters was achieved at 6 keV

Circularly polarized microwaves for magnetic resonance study in the GHz range: Application to nitrogen-vacancy in diamonds

International Nuclear Information System (INIS)

Mrózek, M.; Rudnicki, D. S.; Gawlik, W.; Mlynarczyk, J.

2015-01-01

The ability to create time-dependent magnetic fields of controlled polarization is essential for many experiments with magnetic resonance. We describe a microstrip circuit that allows us to generate strong magnetic field at microwave frequencies with arbitrary adjusted polarization. The circuit performance is demonstrated by applying it to an optically detected magnetic resonance and Rabi nutation experiments in nitrogen-vacancy color centers in diamond. Thanks to high efficiency of the proposed microstrip circuit and degree of circular polarization of 85%; it is possible to address the specific spin states of a diamond sample using a low power microwave generator. The circuit may be applied to a wide range of magnetic resonance experiments with a well-controlled polarization of microwaves

Microstrip natural wave spectrum mathematical model using partial inversion method

International Nuclear Information System (INIS)

Pogarsky, S.A.; Litvinenko, L.N.; Prosvirnin, S.L.

1995-01-01

It is generally agreed that both microstrip lines itself and different discontinuities based on microstrips are the most difficult problem for accurate electrodynamic analysis. Over the last years much has been published about principles and accurate (or full wave) methods of microstrip lines investigations. The growing interest for this problem may be explained by the microstrip application in the millimeter-wave range for purpose of realizing interconnects and a variety of passive components. At these higher operating rating frequencies accurate component modeling becomes more critical. A creation, examination and experimental verification of the accurate method for planar electrodynamical structures natural wave spectrum investigations are the objects of this manuscript. The moment method with partial inversion operator method using may be considered as a basical way for solving this problem. This method is outlook for accurate analysis of different planar discontinuities in microstrip: such as step discontinuities, microstrip turns, Y- and X-junctions and etc., substrate space steps dielectric constants and other anisotropy types

Design of a Microstrip Bowtie Antenna for Indoor Radio-Communications

Directory of Open Access Journals (Sweden)

Fraga-Rosales Hector

2017-01-01

Full Text Available In this paper, a microstrip bowtie patch antenna (MBPA for wireless indoor communications is carried out. Here, a microstrip transmission-line feed network was designed in order to match the MBPA. The proposed antenna uses a ground plane with the aim of narrowing down the back lobes in comparison with bowtie sheet antennas, which radiation pattern is omni-directional. The far-field pattern of the antenna was simulated using a finite-element numerical algorithm and obtained by interpolation employing near-field equipment. The experimental results are described in detail intending to agree well with the simulated predictions. The antenna was designed, measured and built and its far field performance was evaluated with a 2.11 GHz resonant frequency. The azimuth and elevation antenna patterns, antenna gain and, the matching frequency were the main parameters obtained to analyze the antenna behaviour. The antenna has a gain approximately equal to 8.77 dBi and its beam-widths are higher than 100° in E plane.

Ultra-compact microwave filters using kinetic inductance microstrip

International Nuclear Information System (INIS)

Pond, J.M.; Carroll, K.R.; Cukauskas, E.J.

1991-01-01

This paper reports on multi-pole microwave filters designed and fabricated using microstrip transmission line sections which consist of two very thin films of sputtered niobium nitride (NbN) separated by another very thin film of sputtered Si. Since the thicknesses of all three films are much less than the superconducting penetration depth, the kinetic inductance is significantly greater than the magnetic inductance. As a result, the phase velocity of a microstrip transmission line is much less than the free space speed of light. Since resonant structures are reduced in size proportionately, the size and weight of microstrip circuits can be greatly reduced. Prototype filters consisting of four open circuit half-wavelength microstrip stubs separated by full-wavelength microstrip sections have been measured. The circuits are connected to 34 mil diameter coaxial cable via an intermediate coplanar waveguide section. Passbands of 4 GHz separated by 3 GHz reject bands have been measured in a structure which occupies less than 0.5 cm 2 including the coplanar waveguide transitions. Higher-order passbands, although possessing an increased insertion loss, maintain filter passband characteristics through 20.0 GHz

Full-Wave Analysis of Microstrip Antennas in Three-Layered Spherical Media

Directory of Open Access Journals (Sweden)

Tao Yu

2013-01-01

Full Text Available A model of three-layered spherical microstrip antenna has been analyzed based on Rao-Wilton-Glisson (RWG triangular basis functions using mixed potential integral equation (MPIE. Firstly, the model of antenna and the dyadic Green’s function in spherical microstrip antennas are given at the beginning of this paper. Then, due to the infinite series convergence problem, asymptotic extraction approach is presented to accelerate the Green’s functions convergence speed when source and field points are located in the same layer and different layers. The convergence speed can be accelerated observably by using this method. Finally, in order to simplify impedance matrix elements calculation at the junction of the probe and patch, a novel division fashion of pair of triangles is adopted in this paper. The input impedance result obtained shows the validity and effectiveness of the analysis method comparing with published data.

Study of micro-strip gas ionisation chambers substrates for CMS experiment at LHC

International Nuclear Information System (INIS)

Pallares, A.

1996-01-01

High luminosity, expected interaction and dose rates of the future LHC collider require the development of micro-strips gas chambers. In addition to optimization of this new detector, this work is concerned with understanding of gain loss phenomena. Influence of the gas substrate is carefully analysed, as well as theoretical concepts concerning glasses and their behaviour under polarization and irradiation, and the consequence on detection operations.Electron spin resonance is used to study, in standard glass, creation of radiation induced defects which may be charged. (D.L.)

Polarization Property Measurement of the Long Undulator Radiation Using Cr/C Multilayer Polarization Elements

International Nuclear Information System (INIS)

Niibe, Masahito; Mukai, Mikihito; Shoji, Yoshihiko; Kimura, Hiroaki

2004-01-01

A rotating analyzer ellipsometry (RAE) system was developed with Cr/C multilayers that function as polarization elements for photon energy range of 110 - 280 eV. Polarization properties of a planar undulator change axisymmetrically in off-axial manner, and the second harmonic is more remarkable for the change. By using the RAE system, the polarization property of the second harmonic radiation from the NewSUBARU long undulator at the energy of 180 eV was examined. The degree of linear polarization of the on-axis radiation was over 0.996. The spatial distribution of the polarization azimuth was measured and was in fair agreement with the theoretical calculation. A peculiar behavior of the polarization property near the radiation peak of the second harmonic was observed by changing the height of the undulator gap

Polarization-sensitive color in butterfly scales: polarization conversion from ridges with reflecting elements.

Science.gov (United States)

Zhang, Ke; Tang, Yiwen; Meng, Jinsong; Wang, Ge; Zhou, Han; Fan, Tongxiang; Zhang, Di

2014-11-03

Polarization-sensitive color originates from polarization-dependent reflection or transmission, exhibiting abundant light information, including intensity, spectral distribution, and polarization. A wide range of butterflies are physiologically sensitive to polarized light, but the origins of polarized signal have not been fully understood. Here we systematically investigate the colorful scales of six species of butterfly to reveal the physical origins of polarization-sensitive color. Microscopic optical images under crossed polarizers exhibit their polarization-sensitive characteristic, and micro-structural characterizations clarify their structural commonality. In the case of the structural scales that have deep ridges, the polarization-sensitive color related with scale azimuth is remarkable. Periodic ridges lead to the anisotropic effective refractive indices in the parallel and perpendicular grating orientations, which achieves form-birefringence, resulting in the phase difference of two different component polarized lights. Simulated results show that ridge structures with reflecting elements reflect and rotate the incident p-polarized light into s-polarized light. The dimensional parameters and shapes of grating greatly affect the polarization conversion process, and the triangular deep grating extends the outstanding polarization conversion effect from the sub-wavelength period to the period comparable to visible light wavelength. The parameters of ridge structures in butterfly scales have been optimized to fulfill the polarization-dependent reflection for secret communication. The structural and physical origin of polarization conversion provides a more comprehensive perspective on the creation of polarization-sensitive color in butterfly wing scales. These findings show great potential in anti-counterfeiting technology and advanced optical material design.

Microstrip monopulse antenna for land mobile communications

Science.gov (United States)

Garcia, Q.; Martin, C.; Delvalle, J. C.; Jongejans, A.; Rinous, P.; Travers, M. N.

1993-01-01

Low cost is one of the main requirements in a communication system suitable for mass production, as it is the case for satellite land mobile communications. Microstrip technology fulfills this requirement which must be supported by a low cost tracking system design. The tradeoff led us to a prototype antenna composed of microstrip patches based on electromechanical closed-loop principle; the design and the results obtained are described.

Performance of irradiated silicon microstrip detectors

International Nuclear Information System (INIS)

Catacchini, E.; Civinini, C.; D'Alessandro, R.; Focardi, E.; Lenzi, M.; Meschini, M.; Parrini, G.; Pieri, M.

1999-01-01

Silicon microstrip devices to be installed in Large Hadron Collider (LHC) tracking detectors will have to operate in a high radiation environment. We report on performance studies of silicon microstrip detectors irradiated with neutrons or protons, up to fluences comparable to the first ten years of running at LHC. Obtained results show that irradiated detectors can still be operated with satisfactory signal-to-noise ratio,and in the case of inhomogeneously type inverted detector a very good position resolution is achieved regardless of the zone crossed by the particle

Ka-Band Slot-Microstrip-Covered and Waveguide-Cavity-Backed Monopulse Antenna Array

Directory of Open Access Journals (Sweden)

Li-Ming Si

2014-01-01

Full Text Available A slot-microstrip-covered and waveguide-cavity-backed monopulse antenna array is proposed for high-resolution tracking applications at Ka-band. The monopulse antenna array is designed with a microstrip with 2×32 slots, a waveguide cavity, and a waveguide monopulse comparator, to make the structure simple, reduce the feeding network loss, and increase the frequency bandwidth. The 2×32 slot-microstrip elements are formed by a metal clad dielectric substrate and slots etched in the metal using the standard printed circuit board (PCB process with dimensions of 230 mm  ×  10 mm. The proposed monopulse antenna array not only maintains the advantages of the traditional waveguide slot antenna array, but also has the characteristics of wide bandwidth, high consistence, easy of fabrication, and low cost. From the measured results, it exhibits good monopulse characteristics, including the following: the maximum gains of sum pattern are greater than 24 dB, the 3 dB beamwidth of sum pattern is about 2.2 degrees, the sidelobe levels of the sum pattern are less than −18 dB, and the null depths of the difference pattern are less than −25 dB within the operating bandwidth between 33.65 GHz and 34.35 GHz for VSWR ≤ 2.

Wearable Inset-Fed FR4 Microstrip Patch Antenna Design

Science.gov (United States)

Zaini, S. R. Mohd; Rani, K. N. Abdul

2018-03-01

This project proposes the design of a wireless body area network (WBAN) microstrip patch antenna covered by the jeans fabric as the outer layer operating at the center frequency, fc of 2.40 GHz. Precisely, the microstrip patch antenna with the inset-fed edge technique is designed and simulated systematically by using the Keysight Advanced Design System (ADS) software where the FR4 board with the dielectric constant, ɛr of 4.70, dissipation factor or loss tangent, tan δ of 0.02 and height, h of 1.60 mm is the chosen dielectric substrate. The wearable microstrip patch antenna design is then fabricated using the FR4 printed circuit board (PCB) material, hidden inside the jeans fabric, and attached to clothing, such as a jacket accordingly. Simulation and fabrication measurement results show that the designed microstrip patch antenna characteristics can be applied significantly within the industrial, scientific, and medical (ISM) radio band, which is at fc = 2.40 GHz.

A Wideband High-Gain Dual-Polarized Slot Array Patch Antenna for WiMAX Applications in 5.8 GHz

Directory of Open Access Journals (Sweden)

Amir Reza Dastkhosh

2012-01-01

Full Text Available A low-cost, easy-to-fabricate, wideband and high-gain dual-polarized array antenna employing an innovative microstrip slot patch antenna element is designed and fabricated. The design parameters of the antenna are optimized using commercial softwares (Microwave Office and Zeland IE3D to get the suitable -parameters and radiation patterns. Finally, the simulation results are compared to the experimental ones and a good agreement is demonstrated. The antenna has an approximately bandwidth of 14% (5.15–5.9 GHz which covers Worldwide Interoperability Microwave Access (WiMAX/5.8. It also has the peak gain of 26 dBi for both polarizations and high isolation between two ports over a wide bandwidth.

Beam-Steerable Microstrip-Fed Bow-Tie Antenna Array for Fifth Generation Cellular Communications

DEFF Research Database (Denmark)

Ojaroudiparchin, Naser; Shen, Ming; Pedersen, Gert Frølund

2016-01-01

The design and performance of mm-wave phased array antenna for 5G mobile broadband communication systems has been provided in this manuscript. The antenna is designed on a N9000 PTFE substrate with 0.787 mm thickness and 2.2 dielectric constant and 65×130 mm2 overall dimension. Eight elements...... of bow-tie antennas have been used at the top-edge region of mobile phone PCB. The antenna elements fed by microstrip lines are designed to operate at 17 GHz. The simulated results give good performances in terms of different antenna parameters. In addition, an investigation on the distance between...

The design and simulation of UHF RFID microstrip antenna

Science.gov (United States)

Chen, Xiangqun; Huang, Rui; Shen, Liman; Liu, Liping; Xiong, Dezhi; Xiao, Xiangqi; Liu, Mouhai; Renheng, Xu

2018-02-01

At present, China has delineated UHF RFID communicating frequency range which is 840 ∼ 845 MHz and 920 ∼ 925 MHz, but most UHF microstrip antenna don’t carry out this standard, that leads to radio frequency pollution. In order to solve the problems above, a method combining theory and simulation is adopted. Combining with a new ceramic material, a 925.5 MHz RFID microstrip antenna is designed, which is optimized and simulated by HFSS software. The results show that the VSWR of this RFID microstrip antenna is relatively small in the vicinity of 922.5 MHz, the gain is 2.1 dBi, which can be widely used in China’s UHF RFID communicating equipments.

Superconducting microstrip antennas: An experimental comparison of two feeding methods

International Nuclear Information System (INIS)

Richard, M.A.; Claspy, P.C.; Bhasin, K.B.

1993-01-01

The recent discovery of high-temperature superconductors (HTS's) has generated a substantial amount of interest in microstrip antenna applications. However, the high permittivity of substrates compatible with HTS causes difficulty in feeding such antennas because of the high patch edge impedance. In this paper, two methods for feeding HTS microstrip antennas at K and Ka-band are examined. Superconducting microstrip antennas that are directly coupled and gap-coupled to a microstrip transmission line have been designed and fabricated on lanthanum aluminate substrates using Y-Ba-Cu-O superconducting thin films. Measurements from these antennas, including input impedance, bandwidth, efficiency, and patterns, are presented and compared with published models. The measured results demonstrate that usable antennas can be constructed using either of these architectures, although the antennas suffer from narrow bandwidths. In each case, the HTS antenna shows a substantial improvement over an identical antenna made with normal metals

Signal integrity analysis on discontinuous microstrip line

International Nuclear Information System (INIS)

Qiao, Qingyang; Dai, Yawen; Chen, Zipeng

2013-01-01

In high speed PCB design, microstirp lines were used to control the impedance, however, the discontinuous microstrip line can cause signal integrity problems. In this paper, we use the transmission line theory to study the characteristics of microstrip lines. Research results indicate that the discontinuity such as truncation, gap and size change result in the problems such as radiation, reflection, delay and ground bounce. We change the discontinuities to distributed parameter circuits, analysed the steady-state response and transient response and the phase delay. The transient response cause radiation and voltage jump.

Resonance of Superconducting Microstrip Antenna with Aperture in the Ground Plane

Directory of Open Access Journals (Sweden)

S. Benkouda

2013-08-01

Full Text Available This paper presents a rigorous full-wave analysis of a high Tc superconducting rectangular microstrip antenna with a rectangular aperture in the ground plane. To include the effect of the superconductivity of the microstrip patch in the full-wave analysis, a complex surface impedance is considered. The proposed approach is validated by comparing the computed results with previously published data. Results showing the effect of the aperture on the resonance of the superconducting microstrip antenna are given.

A data acquisition system for silicon microstrip detectors

International Nuclear Information System (INIS)

Adriani, O.; Civinini, C.; D'Alessandro, R.; Meschini, M.; Pieri, M.; Castellini, G.

1998-01-01

Following initial work on the readout of the L3 silicon microvertex detector, the authors have developed a complete data acquisition system for silicon microstrip detectors for use both in their home institute and at the various test beam facilities at the CERN laboratory. The system uses extensive decoupling schemes allowing a fully floating connection to the detector. This feature has many advantages especially in the readout of the latest double-sided silicon microstrip detectors

Cryogenic Silicon Microstrip Detector Modules for LHC

CERN Document Server

Perea-Solano, B

2004-01-01

CERN is presently constructing the LHC, which will produce collisions of 7 TeV protons in 4 interaction points at a design luminosity of 1034 cm-2 s-1. The radiation dose resulting from the operation at high luminosity will cause a serious deterioration of the silicon tracker performance. The state-of-art silicon microstrip detectors can tolerate a fluence of about 3 1014 cm-2 of hadrons or charged leptons. This is insufficient, however, for long-term operation in the central parts of the LHC trackers, in particular after the possible luminosity upgrade of the LHC. By operating the detectors at cryogenic temperatures the radiation hardness can be improved by a factor 10. This work proposes a cryogenic microstrip detector module concept which has the features required for the microstrip trackers of the upgraded LHC experiments at CERN. The module can hold an edgeless sensor, being a good candidate for improved luminosity and total cross-section measurements in the ATLAS, CMS and TOTEM experiments. The design o...

Gas microstrip detectors based on flexible printed circuit

International Nuclear Information System (INIS)

Salomon, M.; Crowe, K.; Faszer, W.; Lindsay, P.; Curran Maier, J.M.

1995-09-01

Microstrip Gas Detectors (MSGC's) were introduced some years ago as position sensitive detectors capable of operating at very high rates. The authors have studied the properties of a new type of Gas Microstrip Counter built using flexible printed circuit technology. They describe the manufacturing procedures, the assembly of the device, as well as its operation under a variety of conditions, gases and types of radiation. They also describe two new passivation materials, tantalum and niobium, which produce effective surfaces

Compact MIMO Microstrip Antennas for USB Dongle Operating in 2.5–2.7 GHz Frequency Band

Directory of Open Access Journals (Sweden)

Vladimir Ssorin

2012-01-01

Full Text Available This paper considers design of microstrip MIMO antennas for an LTE/WiMAX USB dongle operating in the 2.5–2.7 GHz frequency band. The MIMO system includes two antenna elements with an additional requirement of high isolation between them that is especially difficult to realize due to size limitations of a USB dongle. Three approaches to achieve the needed system characteristics using microstrip PCB antennas are proposed. For the first design, high port-to-port isolation is achieved by using a decoupling techniques based on a direct connection of the antenna elements. For the second approach, high port-to-port isolation of the MIMO antenna system is realized by a lumped decorrelation capacitance between antenna elements feeding points. The third proposed antenna system does not use any special techniques, and high port-to-port isolation is achieved by using only the properties of a developed printed inverted-F antenna element. The designed MIMO antenna systems have the return loss S11 and the insertion loss S21 bandwidths of more than 200 MHz at the −8 dB level with the correlation coefficient lower than 0.1 and exhibit pattern diversity when different antenna elements are excited. Experimental measurements of the fabricated antenna systems proved the characteristics obtained from electromagnetic simulation.

A New Defected Ground Structure for Different Microstrip Circuit Applications

Directory of Open Access Journals (Sweden)

S. Das

2007-04-01

Full Text Available In this paper, a microstrip transmission line combined with a new U-headed dumb-bell defected ground structure (DGS is investigated. The proposed DGS of two U-shape slots connected by a thin transverse slot is placed in the ground plane of a microstrip line. A finite cutoff frequency and attenuation pole is observed and thus, the equivalent circuit of the DGS unit can be represented by a parallel LC resonant circuit in series with the transmission line. A two-cell DGS microstrip line yields a better lowpass filtering characteristics. The simulation is carried out by the MoM based IE3D software and in the experimental measurements a vector network analyzer is used. The effects of the transverse slot width and the distance between arms of the U-slot on the filter response curve are studied. This DGS is utilized for different microstrip circuit applications. The DGS is placed in the ground of a capacitive loaded microstrip line and a very low cutoff frequency is obtained. The DGS is adopted under the coupled lines of a parallel line coupler and an improvement in coupling coefficient is noticed. The proposed DGS is also incorporated in the ground plane under the feed lines and the coupled lines of a bandpass filter to improve separately the stopband and passband performances.

Excitation of propagating magnetization waves by microstrip antennas

Science.gov (United States)

Dmitriev, V. F.; Kalinikos, B. A.

1988-11-01

We discuss the self-consistent theory of excitation of dipole-exchange magnetization waves by microstrip antennas in a metal-dielectric-ferrite-dielectric-metal stratified structure, magnetized under an arbitrary angle to the surface. Spin-wave Green's functions are derived, describing the response of the spin-system to a spatially inhomogeneous varying magnetic field. The radiative resistance of microstrip antenna is calculated. In this case the distribution of surface current density in the antenna is found on the basis of the analytic solution of a singular integral equation. The nature of the effect of metallic screens and redistributed surface current densities in the antenna on the frequency dependence of the resistive radiation is investigated. Approximate relations are obtained, convenient for practical calculations of radiative resistance of microstrip antennas both in a free and in a screened ferromagnetic film. The theoretical calculations are verified by data of experiments carried out on monocrystalline films of iron-yttrium garnet.

Ultra-Wideband, Dual-Polarized, Beam-Steering P-Band Array Antenna

Science.gov (United States)

duToit, Cornelis

2014-01-01

pair of elements: three apertures coupling to the patch elements were placed along the two symmetry lines of the antenna element pair. Two apertures were used in tandem to excite two of the stacked patch elements for one polarization; the other was used to excite one element from one side and the other element from the other side, opposite in phase, taking care of the remaining polarization. The apertures narrow down to a small gap where they are excited by a crossing microstrip line to prevent any asymmetrical excitation of the two sides of the aperture gap, minimizing port-to-port coupling. Using patches that are non-planar leads to higher mechanical rigidity and smaller patch sizes to fit into the available space. Aperture coupling minimizes direct metal-to-metal connections. Using an aperture coupling feed mechanism results in a feed network for two antenna elements with a total of three feed points, plus one simple in-phase combiner to reduce it to two ports. It greatly reduces the complexity of the alternative, but more conventional, way of feeding a pair of two dual-polarized elements with high port isolation.

ATLAS Silicon Microstrip Tracker

CERN Document Server

Haefner, Petra; The ATLAS collaboration

2010-01-01

The SemiConductor Tracker (SCT), made up from silicon micro-strip detectors is the key precision tracking device in ATLAS, one of the experiments at CERN LHC. The completed SCT is in very good shape: 99.3% of the SCT strips are operational, noise occupancy and hit efficiency exceed the design specifications. In the talk the current status of the SCT will be reviewed. We will report on the operation of the detector and observed problems, with stress on the sensor and electronics performance. TWEPP Summary In December 2009 the ATLAS experiment at the CERN Large Hadron Collider (LHC) recorded the first proton- proton collisions at a centre-of-mass energy of 900 GeV and this was followed by the unprecedented energy of 7 TeV in March 2010. The SemiConductor Tracker (SCT) is the key precision tracking device in ATLAS, made up from silicon micro-strip detectors processed in the planar p-in-n technology. The signal from the strips is processed in the front-end ASICS ABCD3TA, working in the binary readout mode. Data i...

Novel trimming technique for tunable HTS microstrip filters

Energy Technology Data Exchange (ETDEWEB)

Sekiya, N. [Department of Electrical Engineering, Yamanashi University, Nakagawa-Sekiya Laboratory, 4-3-11 Takeda, Kofu 400-8511 (Japan)], E-mail: nsekiya@yamanashi.ac.jp; Nakagawa, Y. [Department of Electrical Engineering, Yamanashi University, Nakagawa-Sekiya Laboratory, 4-3-11 Takeda, Kofu 400-8511 (Japan); Saito, A.; Ohshima, S. [Yamagata University, 4-3-16 Johnan, Yonezawa 992-8510 (Japan)

2008-09-15

We have developed a method using additional electric pads for trimming tunable high-temperature superconducting (HTS) microstrip filters. These filters are generally tuned by adjusting the gap between a dielectric floating plate above the filter. When the floating plate approached the filter, the center frequency was shifted to a lower frequency. However, the insertion loss increases due to variation in the external quality factors varying from the design parameter. The external quality factors are usually controlled by adjusting the length of the input/output (I/O) coupled-line elements and the gap between the elements and the resonator. In our method, additional electric pads are distributed at the open-end of the I/O coupled-line elements of a 3-pole hairpin bandpass filter to enable adjustment of the external quality factors so as to reduce insertion loss. The electric pads consist of line-and-space patterns. They are eclectically connected to the coupled-line elements to adjust the line length and gap width and thereby control the external quality factors. An electromagnetic simulator was used for the design and analysis. The simulation results showed that the additional electric pads are effective in improving the insertion loss of the HTS bandpass filter after tuning.

Novel trimming technique for tunable HTS microstrip filters

International Nuclear Information System (INIS)

Sekiya, N.; Nakagawa, Y.; Saito, A.; Ohshima, S.

2008-01-01

We have developed a method using additional electric pads for trimming tunable high-temperature superconducting (HTS) microstrip filters. These filters are generally tuned by adjusting the gap between a dielectric floating plate above the filter. When the floating plate approached the filter, the center frequency was shifted to a lower frequency. However, the insertion loss increases due to variation in the external quality factors varying from the design parameter. The external quality factors are usually controlled by adjusting the length of the input/output (I/O) coupled-line elements and the gap between the elements and the resonator. In our method, additional electric pads are distributed at the open-end of the I/O coupled-line elements of a 3-pole hairpin bandpass filter to enable adjustment of the external quality factors so as to reduce insertion loss. The electric pads consist of line-and-space patterns. They are eclectically connected to the coupled-line elements to adjust the line length and gap width and thereby control the external quality factors. An electromagnetic simulator was used for the design and analysis. The simulation results showed that the additional electric pads are effective in improving the insertion loss of the HTS bandpass filter after tuning

Fabrication of Feedhorn-Coupled Transition Edge Sensor Arrays for Measurement of the Cosmic Microwave Background Polarization

Science.gov (United States)

Denis, Kevin L.; Aamir, A.; Bennett, C. L.; Chang, M. P.; Chuss, D. T.; Colazo, F. A.; Costen, N.; Essinger-Hileman, T.; Hu, R.; Marriage, T.;

A Microstrip Patch-Fed Short Backfire Antenna for the Tracking and Data Relay Satellite System-Continuation (TDRSS-C) Multiple Access (MA) Array

Science.gov (United States)

Nessel, James A.; Kory, Carol L.; Lambert, Kevin M.; Acosta, Roberto J.

2006-01-01

Short Backfire Antennas (SBAs) are widely utilized for mobile satellite communications, tracking, telemetry, and wireless local area network (WLAN) applications due to their compact structure and excellent radiation characteristics [1-3]. Typically, these SBA s consist of an excitation element (i.e., a half-wavelength dipole), a reflective bottom plane, a planar sub-reflector located above the "exciter", and an outer circular rim. This configuration is capable of achieving gains on the order of 13-15 dBi, but with relatively narrow bandwidths (approx.3%-5%), making it incompatible with the requirements of the next generation enhanced Tracking and Data Relay Satellite System-Continuation (TDRSS-C) Multiple Access (MA) array [1]. Several attempts have been made to enhance the bandwidth performance of the common dipole-fed SBA by employing various other feeding mechanisms (e.g., waveguide, slot) with moderate success [4-5]. In this paper, a novel method of using a microstrip patch is employed for the first time to excite an SBA. The patch element is fed via two H-shaped slots electromagnetically coupled to a broadband hybrid coupler to maintain a wide bandwidth, as well as provide for dual circular polarization capabilities.

Wireless OAM transmission system based on elliptical microstrip patch antenna.

Science.gov (United States)

Chen, Jia Jia; Lu, Qian Nan; Dong, Fei Fei; Yang, Jing Jing; Huang, Ming

2016-05-30

The multiplexing transmission has always been a focus of attention for communication technology. In this paper, the radiation characteristics of circular microstrip patch antenna was firstly analyzed based on cavity model theory, and then spiral beams carrying orbital angular momentum (OAM) were generated, using elliptical microstrip patch antenna, with a single feed probe instead of a standard circular patch with two feedpoints. Moreover, by combining the proposed elliptic microstrip patch antenna with Universal Software Radio Peripheral (USRP), a wireless OAM transmission system was established and the real-time transmission of text, image and video in a real channel environment was realized. Since the wireless OAM transmission has the advantage of good safety and high spectrum utilization efficiency, this work has theoretical significance and potential application.

Circularly Polarized Microwave Antenna Element with Very Low Off-Axis Cross-Polarization

Science.gov (United States)

Greem. David; DuToit, Cornelis

2013-01-01

The goal of this work was to improve off-axis cross-polarization performance and ease of assembly of a circularly polarized microwave antenna element. To ease assembly, the initial design requirement of Hexweb support for the internal circuit part, as well as the radiating disks, was eliminated. There is a need for different plating techniques to improve soldering. It was also desirable to change the design to eliminate soldering as well as the need to use the Hexweb support. Thus, a technique was developed to build the feed without using solder, solving the lathing and soldering issue. Internal parts were strengthened by adding curvature to eliminate Hexweb support, and in the process, the new geometries of the internal parts opened the way for improving the off-axis cross-polarization performance as well. The radiating disks curvatures were increased for increased strength, but it was found that this also improved crosspolarization. Optimization of the curvatures leads to very low off-axis cross-polarization. The feed circuit was curved into a cylinder for improved strength, eliminating Hexweb support. An aperture coupling feed mechanism eliminated the need for feed pins to the disks, which would have required soldering. The aperture coupling technique also improves cross-polarization performance by effectively exciting the radiating disks very close to the antenna s central axis of symmetry. Because of the shape of the parts, it allowed for an all-aluminum design bolted together and assembled with no solder needed. The advantage of a solderless design is that the reliability is higher, with no single-point failure (solder), and no need for special plating techniques in order to solder the unit together. The shapes (curved or round) make for a more robust build without extra support materials, as well as improved offaxis cross-polarization.

A design concept for an MMIC (Monolithic Microwave Integrated Circuit) microstrip phased array

Science.gov (United States)

Lee, Richard Q.; Smetana, Jerry; Acosta, Roberto

1987-01-01

A conceptual design for a microstrip phased array with monolithic microwave integrated circuit (MMIC) amplitude and phase controls is described. The MMIC devices used are 20 GHz variable power amplifiers and variable phase shifters recently developed by NASA contractors for applications in future Ka proposed design, which concept is for a general NxN element array of rectangular lattice geometry. Subarray excitation is incorporated in the MMIC phased array design to reduce the complexity of the beam forming network and the number of MMIC components required.

A Compact Annular Ring Microstrip Antenna for WSN Applications

Directory of Open Access Journals (Sweden)

Daihua Wang

2012-06-01

Full Text Available A compact annular ring microstrip antenna was proposed for a wireless sensor network (WSN application in the 2.4 GHz band. In this paper the major considerations of the conformal antenna design were the compact size and the impact on antenna’s performance of a steel installation base. By using a chip resistor of large resistance (120 Ω the antenna size was reduced to 38% of that a conventional annular ring patch antenna. With the addition of the steel installation base the resonant frequency of the antenna increases about 4.2% and the bandwidth reduces from 17.5% to 11.7% by adjusting the load resistance simultaneously. Several key parameters were discussed and optimized, and the antenna was fabricated and its performance measured. The antenna is well matched at 2.4 GHz with 34.2 dB return loss and –2.5 dBi peak gain. Meanwhile, it exhibits excellent radiation patterns with very low cross-polarization levels.

Microstrip microwave band gap structures

Indian Academy of Sciences (India)

The periodic lattice of PTFE–air combination has the dielectric contrast (defined as the ratio between the dielectric constant of the substrate to that of the background, air) of 2.08. At both ends of the microstrip. MBG, two sub-miniature adapter (SMA) coaxial connectors were placed. The measurements as well as theoretical ...

Aleph silicon microstrip vertex detector

CERN Multimedia

Laurent Guiraud

1998-01-01

This microstrip vertex locator was located at the heart of the ALEPH experiment, one of the four experiments at the Large Electron-Positron (LEP) collider. In the experiments at CERN's LEP, which ran from 1989 to 2000, modern silicon microvertex detectors, such as those used at ALEPH, monitored the production of short-lived particles close to the beam pipe.

Adaptive Forming of the Beam Pattern of Microstrip Antenna with the Use of an Artificial Neural Network

Directory of Open Access Journals (Sweden)

Janusz Dudczyk

2012-01-01

Full Text Available Microstrip antenna has been recently one of the most innovative fields of antenna techniques. The main advantage of such an antenna is the simplicity of its production, little weight, a narrow profile, and easiness of integration of the radiating elements with the net of generators power systems. As a result of using arrays consisting of microstrip antennas; it is possible to decrease the size and weight and also to reduce the costs of components production as well as whole application systems. This paper presents possibilities of using artificial neural networks (ANNs in the process of forming a beam from radiating complex microstrip antenna. Algorithms which base on artificial neural networks use high parallelism of actions which results in considerable acceleration of the process of forming the antenna pattern. The appropriate selection of learning constants makes it possible to get theoretically a solution which will be close to the real time. This paper presents the training neural network algorithm with the selection of optimal network structure. The analysis above was made in case of following the emission source, setting to zero the pattern of direction of expecting interference, and following emission source compared with two constant interferences. Computer simulation was made in MATLAB environment on the basis of Flex Tool, a programme which creates artificial neural networks.

MULTIOBJECTIVE EVOLUTIONARY ALGORITHMS APPLIED TO MICROSTRIP ANTENNAS DESIGN ALGORITMOS EVOLUTIVOS MULTIOBJETIVO APLICADOS A LOS PROYECTOS DE ANTENAS MICROSTRIP

Directory of Open Access Journals (Sweden)

Juliano Rodrigues Brianeze

2009-12-01

Full Text Available This work presents three of the main evolutionary algorithms: Genetic Algorithm, Evolution Strategy and Evolutionary Programming, applied to microstrip antennas design. Efficiency tests were performed, considering the analysis of key physical and geometrical parameters, evolution type, numerical random generators effects, evolution operators and selection criteria. These algorithms were validated through design of microstrip antennas based on the Resonant Cavity Method, and allow multiobjective optimizations, considering bandwidth, standing wave ratio and relative material permittivity. The optimal results obtained with these optimization processes, were confirmed by CST Microwave Studio commercial package.Este trabajo presenta tres de los principales algoritmos evolutivos: Algoritmo Genético, Estrategia Evolutiva y Programación Evolutiva, aplicados al diseño de antenas de microlíneas (microstrip. Se realizaron pruebas de eficiencia de los algoritmos, considerando el análisis de los parámetros físicos y geométricos, tipo de evolución, efecto de generación de números aleatorios, operadores evolutivos y los criterios de selección. Estos algoritmos fueron validados a través del diseño de antenas de microlíneas basado en el Método de Cavidades Resonantes y permiten optimizaciones multiobjetivo, considerando ancho de banda, razón de onda estacionaria y permitividad relativa del dieléctrico. Los resultados óptimos obtenidos fueron confirmados a través del software comercial CST Microwave Studio.

Standardization of Schwarz-Christoffel transformation for engineering design of semiconductor and hybrid integrated-circuit elements

Science.gov (United States)

Yashin, A. A.

1985-04-01

A semiconductor or hybrid structure into a calculable two-dimensional region mapped by the Schwarz-Christoffel transformation and a universal algorithm can be constructed on the basis of Maxwell's electro-magnetic-thermal similarity principle for engineering design of integrated-circuit elements. The design procedure involves conformal mapping of the original region into a polygon and then the latter into a rectangle with uniform field distribution, where conductances and capacitances are calculated, using tabulated standard mapping functions. Subsequent synthesis of a device requires inverse conformal mapping. Devices adaptable as integrated-circuit elements are high-resistance film resistors with periodic serration, distributed-resistance film attenuators with high transformation ratio, coplanar microstrip lines, bipolar transistors, directional couplers with distributed coupling to microstrip lines for microwave bulk devices, and quasirregular smooth matching transitions from asymmetric to coplanar microstrip lines.

2D position sensitive microstrip sensors with charge division along the strip Studies on the position measurement error

CERN Document Server

Bassignana, D; Fernandez, M; Jaramillo, R; Lozano, M; Munoz, F.J; Pellegrini, G; Quirion, D; Vila, I; Vitorero, F

2013-01-01

Position sensitivity in semiconductor detectors of ionizing radiation is usually achieved by the segmentation of the sensing diode junction in many small sensing elements read out separately as in the case of conventional microstrips and pixel detectors. Alternatively, position sensitivity can be obtained by splitting the ionization signal collected by one single electrode amongst more than one readout channel with the ratio of the collected charges depending on the position where the signal was primary generated. Following this later approach, we implemented the charge division method in a conventional microstrip detector to obtain position sensitivity along the strip. We manufactured a proofof-concept demonstrator where the conventional aluminum electrodes were replaced by slightly resistive electrodes made of strongly doped poly-crystalline silicon and being readout at both strip ends. Here, we partially summarize the laser characterization of this first proof-of-concept demonstrator with special emphasis ...

A portable readout system for silicon microstrip sensors

International Nuclear Information System (INIS)

Marco-Hernandez, Ricardo

2010-01-01

This system can measure the collected charge in one or two microstrip silicon sensors by reading out all the channels of the sensor(s), up to 256. The system is able to operate with different types (p- and n-type) and different sizes (up to 3 cm 2 ) of microstrip silicon sensors, both irradiated and non-irradiated. Heavily irradiated sensors will be used at the Super Large Hadron Collider, so this system can be used to research the performance of microstrip silicon sensors in conditions as similar as possible to the Super Large Hadron Collider operating conditions. The system has two main parts: a hardware part and a software part. The hardware part acquires the sensor signals either from external trigger inputs, in case of a radioactive source setup is used, or from a synchronised trigger output generated by the system, if a laser setup is used. The software controls the system and processes the data acquired from the sensors in order to store it in an adequate format. The main characteristics of the system are described. Results of measurements acquired with n- and p-type detectors using both the laser and the radioactive source setup are also presented and discussed.

Bandwidth enhancement of a microstrip patch antenna for ultra-wideband applications

Science.gov (United States)

Anum, Khanda; Singh, Milind Saurabh; Mishra, Rajan; Tripathi, G. S.

2018-04-01

The microstrip antennas are used where size, weight, cost, and performance are constraints. Microstrip antennas (MSA) are being used in many government and commercial applications among which it is mostly used in wireless communication. The proposed antenna is designed for Ultra-wideband (UWB), it is designed on FR4 substrate material with ɛr = 4.3 and 0.0025 loss tangent. The shape and size of patch in microstrip patch antenna plays an important role in its performance. In the proposed antenna design the respective changes have been introduced which includes slotting the feedline,adding a curved slot in patch and change in patch shape itself to improve the bandwidth of the conventional antenna. The simulated results of proposed antenna shows impedance bandwidth (defined by 10 dB return loss) of 2-11.1GHz, VSWRcommunication at 7.25-8.395 GHz.

Optically controlled photonic bandgap structures for microstrip circuits

International Nuclear Information System (INIS)

Cadman, Darren Arthur

2003-01-01

This thesis is concerned with the optical control of microwave photonic bandgap circuits using high resistivity silicon. Photoconducting processes that occur within silicon are investigated. The influence of excess carrier density on carrier mobility and lifetime is examined. In addition, electron-hole pair recombination mechanisms (Shockley-Read-Hall, Auger, radiative and surface) are investigated. The microwave properties of silicon are examined, in particular the variation of silicon reflectivity with excess carrier density. Filtering properties of microstrip photonic bandgap structures and how they may be controlled optically are studied. A proof-of-concept microstrip photonic bandgap structure with optical control is designed, simulated and measured. With no optical illumination incident upon the silicon, the microstrip photonic bandgap structure's filtering properties are well-defined; a 3dB stopband width of 2.6GHz, a 6dB bandwidth of 2GHz and stopband depth of -11.6dB at the centre frequency of 9.9GHz. When the silicon is illuminated, the structure's filtering properties are suppressed. Under illumination the experimental results display an increase in S 21 of 6.5dB and a reduction in S 11 of more than 10dB at 9.9GHz. A comparison of measured and simulated results reveal that the photogenerated excess carrier density is between 4 x 10 15 cm -3 and 1.1 x 10 16 cm -3 . (author)

Two-dimensional microstrip detector for neutrons

Energy Technology Data Exchange (ETDEWEB)

Oed, A [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

1997-04-01

Because of their robust design, gas microstrip detectors, which were developed at ILL, can be assembled relatively quickly, provided the prefabricated components are available. At the beginning of 1996, orders were received for the construction of three two-dimensional neutron detectors. These detectors have been completed. The detectors are outlined below. (author). 2 refs.

Solid-phase extraction element based on epoxy polymer monolith for determination of polar organic compounds in aqueous media.

Science.gov (United States)

Takahashi, Tadashi; Odagiri, Kayo; Watanabe, Atsushi; Watanabe, Chuichi; Kubo, Takuya; Hosoya, Ken

2011-10-01

A solid-phase extraction element based on epoxy polymer monolith was fabricated for sorptive enrichment of polar compounds from liquid and gaseous samples. After ultrasonication of the element in an aqueous solution for a given period of time, the thermal desorption (TD) using a pyrolyzer with gas chromatography/mass spectrometry (GC/MS), in which TD temperature was programmed from 50 to 250 °C for the analytes absorbed in the element, was used to evaluate the element for basic extraction performance using the aqueous standard mixtures consisting of compounds having varied polarities such as hexanol, isoamyl acetate, linalool, furfural and decanoic acid, in concentrations ranging from 10 μg/L to 1 mg/L. Excellent linear relationships were observed for all compounds in the standard mixture, except decanoic acid. In the extraction of beverages such as red wine, the extraction element showed stronger adsorption characteristics for polar compounds such as alcohols and acids than a non-polar polydimethylsiloxane-based element. This feature is derived from the main polymer structure along with hydroxyl and amino groups present in the epoxy-based monolith polymer matrix. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Circular Microstrip Patch Array Antenna for C-Band Altimeter System

Directory of Open Access Journals (Sweden)

Asghar Keshtkar

2008-01-01

Full Text Available The purpose of this paper is to discuss the practical and experimental results obtained from the design, construction, and test of an array of circular microstrip elements. The aim of this antenna construction was to obtain a gain of 12 dB, an acceptable pattern, and a reasonable value of SWR for altimeter system application. In this paper, the cavity model was applied to analyze the patch and a proper combination of ordinary formulas; HPHFSS software and Microwave Office software were used. The array includes four circular elements with equal sizes and equal spacing and was planed on a substrate. The method of analysis, design, and development of this antenna array is explained completely here. The antenna is simulated and is completely analyzed by commercial HPHFSS software. Microwave Office 2006 software has been used to initially simulate and find the optimum design and results. Comparison between practical results and the results obtained from the simulation shows that we reached our goals by a great degree of validity.

Development of ALICE microstrip detectors at IRST

International Nuclear Information System (INIS)

Boscardin, M.; Bosisio, L.; Dalla Betta, G.-F.; Gregori, P.; Rachevskaia, I.; Zorzi, N.

2001-01-01

We report on the development of double-sided, AC-coupled, microstrip detectors oriented to the A Large Ion Collider Experiment (ALICE). The main design and processing issues are presented, together with some selected results from the electrical characterization of detectors and related test structures

Accelerated life test of an ONO stacked insulator film for a silicon micro-strip detector

International Nuclear Information System (INIS)

Okuno, Shoji; Ikeda, Hirokazu; Saitoh, Yutaka

1996-01-01

We have used to acquire the signal through an integrated capacitor for a silicon micro-strip detector. When we have been using a double-sided silicon micro-strip detector, we have required a long-term stability and a high feasibility for the integrated capacitor. An oxide-nitride-oxide (ONO) insulator film was theoretically expected to have a superior nature in terms of long term reliability. In order to test long term reliability for integrated capacitor of a silicon micro-strip detector, we made a multi-channel measuring system for capacitors

Antennas for mobile satellite communications

Science.gov (United States)

Huang, John

1991-12-01

A NASA sponsored program, called the Mobile Satellite (MSAT) system, has prompted the development of several innovative antennas at L-band frequencies. In the space segment of the MSAT system, an efficient, light weight, circularly polarized microstrip array that uses linearly polarized elements was developed as a multiple beam reflector feed system. In the ground segment, a low-cost, low-profile, and very efficient microstrip Yagi array was developed as a medium-gain mechanically steered vehicle antenna. Circularly shaped microstrip patches excited at higher-order modes were also developed as low-gain vehicle antennas. A more recent effort called for the development of a 20/30 GHz mobile terminal antenna for future-generation mobile satellite communications. To combat the high insertion loss encountered at 20/30 GHz, series-fed Monolithic Microwave Integrated Circuit (MMIC) microstrip array antennas are currently being developed. These MMIC arrays may lead to the development of several small but high-gain Ka-band antennas for the Personal Access Satellite Service planned for the 2000s.

A Design of Wide Band and Wide Beam Cavity-Backed Slot Antenna Array with Slant Polarization

Directory of Open Access Journals (Sweden)

Huiying Qi

2016-01-01

Full Text Available Design of antenna array under the limitation of restricted size is a challenging problem. Cavity-backed slot antenna is widely used because of its advantages of small size, wide band, and wide beam. In this paper, a design of wide band and wide beam cavity-backed slot antenna array with the slant polarization is proposed. To obtain wide band and wide beam with limited size, the inverted microstrip-fed cavity-backed slot antenna (IMF-CBSA is adopted as the element of 1 × 4 antenna array. The slant polarized antennas and their feeding networks are adopted because of their simple structures. The performance of the proposed antenna array is verified by the simulations and experiments. The measured VSWR < 2 bandwidth is 55% at the center frequency 21.8 GHz, and the gain is larger than 12.2 dB. Experimental results demonstrate that the proposed design achieves wide band and beam with the size of 68 mm × 56 mm × 14.5 mm.

Integrated double-sided silicon microstrip detectors

Directory of Open Access Journals (Sweden)

Perevertailo V. L.

2011-11-01

Full Text Available The problems of design, technology and manufacturing double-sided silicon microstrip detectors using standard equipment production line in mass production of silicon integrated circuits are considered. The design of prototype high-energy particles detector for experiment ALICE (CERN is presented. The parameters of fabricated detectors are comparable with those of similar foreign detectors, but they are distinguished by lesser cost.

High resistivity ZnSe coated substrates for microstrip gas chambers

International Nuclear Information System (INIS)

Sudharsanan, R.; Greenwald, A.C.; Vakerlis, G.; Yoganathan, M.; Cho, H.S.; Kadyk, J.; Dubeau, J.; Dixit, M.

1998-01-01

Microstrip gas chambers (MSGCs) require substrates with sheet resistance in the range of 10 13 --10 16 ohms/square to eliminate polarization and surface charging effects between the electrodes. Thin films of II-VI semiconductors deposited on glass or plastic substrates are attractive for this application since bulk resistivity of these semiconductors vary in the range 10 9 --10 12 ohm-cm and films with good uniformity can be deposited over large-areas using inexpensive deposition techniques. In this paper, deposition, characterization, and fabrication of MSGCs using ZnSe thin films are reported for the first time. ZnSe thin films were deposited on glass and plastic substrates by thermal evaporation. Sheet resistance of ZnSe varied in the range of 10 15 to 10 16 ohms/square depending on the deposition conditions. A MSGC detector fabricated using a 0.5 microm thick ZnSe layer on glass substrate exhibited best values; gas gain of 25,000 and an energy resolution of about 16.7% FWHM at a gain of 1,080 for a 55 Fe source

Build-up of the silicon micro-strip detector array in ETF of HIRFL-CSR

International Nuclear Information System (INIS)

Wang Pengfei; Li Zhankui; Li Haixia

2014-01-01

Silicon micro-strip detectors have been widely used in the world-famous nuclear physics laboratories due to their better position resolution and energy resolution. Double-sided silicon micro-strip detectors with a position resolution of 0.5 mm × 0.5 mm, have been fabricated in the IMP (Institute of Modern Physics, CAS) by using microelectronics technology. These detectors have been used in the ETF (External Target Facility) of HIRFL-CSR, as ΔE detectors of the ΔE-E telescope system and the track detectors. With the help of flexibility printed circuit board (FPCB) and the integrated ASIC chips, a compact multi-channel front-end electronic board has been designed to fulfill the acquisition of the energy and position information of the Silicon micro-strip detectors. It is described in this paper that the build-up of the Silicon micro-strip detector array in ETF of HIRFL-CSR, the determination of the energy resolution of the detector units, and the energy resolution of approximately 1% obtained for 5∼9 MeV α particles in vacuum. (authors)

Analysis of superconducting microstrip resonator at various microwave power levels

International Nuclear Information System (INIS)

Srivastava, G.P.; Jacob, M.V.; Jayakumar, M.; Bhatnagar, P.K.; Kataria, N.D.

1997-01-01

The real and imaginary parts of the surface impedance of YBCO superconductors have been studied at different microwave power levels. Using the relations for the critical current density and the grain boundary resistance, a relation for calculating the power dependence of the surface resistance has been obtained. Also, a relation to find the resonant frequency of a superconducting microstrip resonator at various input power levels has been derived. Measurements have been carried out on various microstrip resonators to study the variation of surface resistance and resonant frequency at different rf power levels. The experimental results are in good agreement with theoretical results. copyright 1997 American Institute of Physics

Geometrical optimization of microstripe arrays for microbead magnetophoresis

DEFF Research Database (Denmark)

Henriksen, Anders Dahl; Rozlosnik, Noemi; Hansen, Mikkel Fougt

2015-01-01

Manipulation of magnetic beads plays an increasingly important role in molecular diagnostics. Magnetophoresis is a promising technique for selective transportation of magnetic beads in lab-on-a-chip systems. We investigate periodic arrays of exchange-biased permalloy microstripes fabricated using...

Selective area epitaxy of monolithic white-light InGaN/GaN quantum well microstripes with dual color emission

Energy Technology Data Exchange (ETDEWEB)

Li, Yuejing; Tong, Yuying; Yang, Guofeng, E-mail: gfyang@jiangnan.edu.cn; Yao, Chujun; Sun, Rui; Cai, Lesheng; Xu, Guiting; Wang, Jin; Zhang, Qing; Ye, Xuanchao; Wu, Mengting; Wen, Zhiqin [School of Science, Jiangnan University, Wuxi 214122 (China)

2015-09-15

Monolithic color synthesis is demonstrated using InGaN/GaN multiple quantum wells (QWs) grown on GaN microstripes formed by selective area epitaxy on SiO{sub 2} mask patterns. The striped microfacet structure is composed of (0001) and (11-22) planes, attributed to favorable surface polarity and surface energy. InGaN/GaN QWs on different microfacets contain spatially inhomogeneous compositions owing to the diffusion of adatoms among the facets. This unique property allows the microfacet QWs to emit blue light from the (11-22) plane and yellow light from the top (0001) plane, the mixing of which leads to the perception of white light emission.

Selective area epitaxy of monolithic white-light InGaN/GaN quantum well microstripes with dual color emission

International Nuclear Information System (INIS)

Li, Yuejing; Tong, Yuying; Yang, Guofeng; Yao, Chujun; Sun, Rui; Cai, Lesheng; Xu, Guiting; Wang, Jin; Zhang, Qing; Ye, Xuanchao; Wu, Mengting; Wen, Zhiqin

2015-01-01

Monolithic color synthesis is demonstrated using InGaN/GaN multiple quantum wells (QWs) grown on GaN microstripes formed by selective area epitaxy on SiO 2 mask patterns. The striped microfacet structure is composed of (0001) and (11-22) planes, attributed to favorable surface polarity and surface energy. InGaN/GaN QWs on different microfacets contain spatially inhomogeneous compositions owing to the diffusion of adatoms among the facets. This unique property allows the microfacet QWs to emit blue light from the (11-22) plane and yellow light from the top (0001) plane, the mixing of which leads to the perception of white light emission

Silicon microstrip detectors for the ATLAS SCT

Czech Academy of Sciences Publication Activity Database

Robinson, D.; Allport, P.; Andricek, L.; Böhm, Jan; Buttar, C.; Carter, J. R.; Chilingarov, A.; Clark, A. G.; Feriere, D.; Fuster, J.

2002-01-01

Roč. 485, 1-2 (2002), s. 84-88 ISSN 0168-9002 R&D Projects: GA MPO RP-4210/69 Institutional research plan: CEZ:AV0Z1010920 Keywords : ATLAS SCT * silicon microstrip detectors * irradiation * quality control Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.167, year: 2002

SPICE evaluation of the S/N ratio for Si microstrip detectors

International Nuclear Information System (INIS)

Candelori, A.; Paccagnella, A.; Padova Univ.; Nardi, F.

1999-01-01

SPICE simulations of AC-coupled single-sided Si microstrip detectors connected to the Pre-Shape 32 read-out chip have been performed in order to determine the geometrical characteristics which maximize the signal-to-noise ratio at room temperature. All the resistive and capacitive elements of the detector have been determined as a function of the ω/ρ ratio, by considering experimental and simulated data available in the literature. The SPICE model takes into account all the main noise source in the detector and read-out electronics. The minimum ionizing particle current signal shape characteristics have been introduced in the simulations. Two read-out configurations have been investigated for 6.4 cm and 12.8 cm long detectors. Finally, general guidelines in the detector design have been proposed starting from the simulation results

A Design of a Terahertz Microstrip Bandstop Filter with Defected Ground Structure

Directory of Open Access Journals (Sweden)

Arjun Kumar

2013-01-01

Full Text Available A planar microstrip terahertz (THz bandstop filter has been proposed with defected ground structure with high insertion loss (S21 in a stopband of −25.8 dB at 1.436 THz. The parameters of the circuit model have been extracted from the EM simulation results. A dielectric substrate of Benzocyclobutene (BCB is used to realize a compact bandstop filter using modified hexagonal dumbbell-shape defected ground structure (DB-DGS. In this paper, a defected ground structure topology is used in a λ/4, 50 Ω microstrip line at THz frequency range for compactness. No article has been reported on the microstrip line at terahertz frequency regime using DGS topology. The proposed filter can be used for sensing and detection in biomedical instruments in DNA testing. All the simulations/cosimulations are carried out using a full-wave EM simulator CST V.9 Microwave Studio, HFSS V.10, and Agilent Design Suite (ADS.

Design, simulation and analysis a microstrip antenna using PU-EFB substrate

Science.gov (United States)

Mahmud, S. N. S.; Jusoh, M. A.; Jasim, S. E.; Zamani, A. H.; Abdullah, M. H.

2018-04-01

A low cost, light weight and easy to fabricate are the most important factor for future antennas. Microstrip patch antennas offer these advantages and suitable for communication and sensor application. This paper presents a design of simple microstrip patch antenna working on operating frequency of 2.4 GHz. The designed process has been carried out using MATLAB and HFSS software by entering 2.3 for the dielectric constant of PU-EFB. The results showed that high return loss, low bandwidth and good antenna radiation efficiency of which are -21.98 dB, 0.28 dB and 97.33%, respectively.

ATLAS Silicon Microstrip Tracker Operation and Performance

CERN Document Server

Yamada, M; The ATLAS collaboration

2011-01-01

The SemiConductor Tracker (SCT), comprising of silicon micro-strip detectors is one of the key precision tracking devices in the ATLAS Inner Detector. ATLAS is one of the experiments at CERN LHC. The completed SCT is in very good shapes with 99.3% of the SCT’s 4088 modules (a total of 6.3 million strips) are operational. The noise occupancy and hit efficiency exceed the design specifications. In the talk the current status of the SCT will be reviewed. We will report on the operation of the detector, its performance and observed problems, with stress on the sensor and electronics performance. In December 2009 the ATLAS experiment at the CERN Large Hadron Collider (LHC) recorded the first proton-proton collisions at a centre-of-mass energy of 900 GeV and this was followed by the unprecedented energy of 7 TeV in March 2010. The Semi-Conductor Tracker (SCT) is the key precision tracking device in ATLAS, made from silicon micro-strip detectors processed in the planar p-in-n technology. The signals from the strip...

Degradation of silicon AC-coupled microstrip detectors induced by radiation

Science.gov (United States)

Bacchetta, N.; Bisello, D.; Canali, C.; Fuochi, P. G.; Gotra, Y.; Paccagnella, A.; Verzellesi, G.

1993-12-01

Results are presented showing the radiation response of AC-coupled FOXFET biased microstrip detectors and related test patterns to be used in the microvertex detector of the CDF experiment at Fermi National Laboratory. Radiation tolerance of detectors to gamma and proton irradiation has been tested, and the radiation-induced variations of the DC electrical parameters have been analyzed. The long-term postirradiation behavior of detector characteristics has been studied, and the relevant room-temperature annealing phenomena have been examined. The main radiation damage effects after gamma or proton irradiation of FOXFET biased microstrip detectors consist of an increase in the total leakage current, while both the detector dynamic resistance and FOXFET switching voltage decrease.

Design of microstrip patch antennas using knowledge insertion through retraining

Science.gov (United States)

Divakar, T. V. S.; Sudhakar, A.

2018-04-01

The traditional way of analyzing/designing neural network is to collect experimental data and train neural network. Then, the trained neural network acts as global approximate function. The network is then used to calculate parameters for unknown configurations. The main drawback of this method is one does not have enough experimental data, cost of prototypes being a major factor [1-4]. Therefore, in this method the author collected training data from available approximate formulas with in full design range and trained the network with it. After successful training, the network is retrained with available measured results. This simple way inserts experimental knowledge into the network [5]. This method is tested for rectangular microstrip antenna and circular microstrip antenna.

The silicon tracking system of the CBM experiment at FAIR. Development of microstrip sensors and signal transmission lines for a low-mass, low-noise system

International Nuclear Information System (INIS)

Singla, Minni

2014-01-01

construction of the silicon microstrip sensors. For the evaluation of the performance of the silicon microstrip sensors in the harsh radiation environment during experimental operation, a radiation damage model has been included. It reproduces the behavior of the irradiated CBM prototype sensors. In addition to the static characteristics, the interstrip parameters relevant to understand strip isolation and cross-talk issues have been extracted. The transient simulations have been performed to estimate the charge collection performance of the irradiated sensors. The signal transmission in the readout cables has been evaluated with the finite element simulation tool RAPHAEL. Based on the performance of the front-end electronics used for early prototyping in the CBM experiment, capacitive and resistive noise contributions from the silicon microstrip sensors and multi-line readout cables have been extracted. To validate the aforementioned simulations, numerous tests have been performed both on the multi-line readout cables and silicon microstrip sensors. Characterizations of multi-line readout cables and silicon microstrip sensors in laboratory conditions have been found to agree reasonably well with the simulations. Considering the expected radiation environment the behavior of silicon microstrip sensors have been studied especially in terms of noise and charge collection efficiency. scan of the silicon microstrip sensors using 241 Am is presented. In order to test a first system of detector stations including the data acquisition system, slow control and online monitoring software and for track reconstruction, in-beam tests have been performed at the COSY synchrotron of the Research Center Juelich, Germany. Further, different design parameters have been suggested to improve the sensor and readout cable design on the basis of the simulations and the measurements. Many of these parameters have been implemented in the new prototypes under production. These new prototypes were

SCRLH-TL Based Sequential Rotation Feed Network for Broadband Circularly Polarized Antenna Array

Directory of Open Access Journals (Sweden)

B. F. Zong

2016-04-01

Full Text Available In this paper, a broadband circularly polarized (CP microstrip antenna array using composite right/left-handed transmission line (SCRLH-TL based sequential rotation (SR feed network is presented. The characteristics of a SCRLH-TL are initially investigated. Then, a broadband and low insertion loss 45º phase shifter is designed using the SCRLH-TL and the phase shifter is employed in constructing a SR feed network for CP antenna array. To validate the design method of the SR feed network, a 2×2 antenna array comprising sequentially rotated coupled stacked CP antenna elements is designed, fabricated and measured. Both the simulated and measured results indicate that the performances of the antenna element are further enhanced when the SR network is used. The antenna array exhibits the VSWR less than 1.8 dB from 4 GHz to 7 GHz and the 3 dB axial ratio (AR from 4.4 GHz to 6.8 GHz. Also, high peak gain of 13.7 dBic is obtained. Besides, the normalized radiation patterns at the operating frequencies are symmetrical and the side lobe levels are low at φ=0º and φ=90º.

Geographic distribution of selected elements in the livers of polar bears from Greenland, Canada and the United States

International Nuclear Information System (INIS)

Rush, Scott A.; Borga, Katrine; Dietz, Rune; Born, Erik W.; Sonne, Christian; Evans, Thomas; Muir, Derek C.G.; Letcher, Robert J.; Norstrom, Ross J.; Fisk, Aaron T.

2008-01-01

To assess geographic distributions of elements in the Arctic we compared essential and non-essential elements in the livers of polar bears (Ursus maritimus) collected from five regions within Canada in 2002, in Alaska between 1994 and 1999 and from the northwest and east coasts of Greenland between 1988 and 2000. As, Hg, Pb and Se varied with age, and Co and Zn with gender, which limited spatial comparisons across all populations to Cd, which was highest in Greenland bears. Collectively, geographic relationships appeared similar to past studies with little change in concentration over time in Canada and Greenland for most elements; Hg and Se were higher in some Canadian populations in 2002 as compared to 1982 and 1984. Concentrations of most elements in the polar bears did not exceed toxicity thresholds, although Cd and Hg exceeded levels correlated with the formation of hepatic lesions in laboratory animals. - Geographical trends were observed for a number of elements in livers, including mercury, of polar bears collected across Alaska, Canada and Greenland and were similar to those observed in the early 1980s

Dual-band linearly and circularly polarized microstrip patch antennas with meandering slot and metallic vias

DEFF Research Database (Denmark)

Zhang, Jin; Lin, Xianqi; Yu, Jiawei

2018-01-01

performances. The characteristics are analyzed in detail where we find that the existence of the vias also improves the impedance matching. Four samples are designed, where dual-band with both linear polarization, dual-band with circular- and linear-polarization, and single band with linear polarization...

ATLAS Silicon Microstrip Tracker Operation and Performance

CERN Document Server

Rosendahl, P L; The ATLAS collaboration

2012-01-01

The Semi-Conductor Tracker (SCT) is a silicon microstrip detector part of the ATLAS experiment at the CERN Large Hadron Collider (LHC). Together with the rest for the ATLAS Inner Detector (ID) it provides vital precision tracking information of charged particles. In this paper the performance and operational status of the SCT in the last two years of ATLAS data taking are reviewed.

Two-loop massive operator matrix elements for polarized and unpolarized deep-inelastic scattering

Energy Technology Data Exchange (ETDEWEB)

Bierenbaum, I.; Bluemlein, J.; Klein, S.

2007-06-15

The O({alpha}{sup 2}{sub s}) massive operator matrix elements for unpolarized and polarized heavy flavor production at asymptotic values Q{sup 2} >> m{sup 2} are calculated in Mellin space without applying the integration-by-parts method. (orig.)

The silicon microstrip sensors of the ATLAS semiconductor tracker

Czech Academy of Sciences Publication Activity Database

Ahmad, A.; Albrechtskirchinger, Z.; Allport, P.; Böhm, Jan; Mikeštíková, Marcela; Šťastný, Jan

2007-01-01

Roč. 578, - (2007), s. 98-118 ISSN 0168-9002 Institutional research plan: CEZ:AV0Z10100502 Keywords : ATLAS * SCT * silicon * microstrip * module * LHC Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.114, year: 2007

Electromagnetic Design of Feedhorn-Coupled Transition-Edge Sensors for Cosmic Microwave Background Polarimetery

Science.gov (United States)

Chuss, David T.

2011-01-01

Observations of the cosmic microwave background (CMB) provide a powerful tool for probing the evolution of the early universe. Specifically, precision measurement of the polarization of the CMB enables a direct test for cosmic inflation. A key technological element on the path to the measurement of this faint signal is the capability to produce large format arrays of background-limited detectors. We describe the electromagnetic design of feedhorn-coupled, TES-based sensors. Each linear orthogonal polarization from the feed horn is coupled to a superconducting microstrip line via a symmetric planar orthomode transducer (OMT). The symmetric OMT design allows for highly-symmetric beams with low cross-polarization over a wide bandwidth. In addition, this architecture enables a single microstrip filter to define the passband for each polarization. Care has been taken in the design to eliminate stray coupling paths to the absorbers. These detectors will be fielded in the Cosmology Large Angular Scale Surveyor (CLASS).

Analysis of Rectangular Microstrip Antennas with Air Substrates ...

African Journals Online (AJOL)

This paper presents an analysis of rectangular microstrip antennas with air substrates. The effect of the substrate thickness on the bandwidth and the efficiency are examined. An additional thin layer supporting the dielectric material is added to the air substrate in order to make the antenna mechanically rigid and easy to ...

Use of silicon microstrip detectors in medical diagnostic x-rays

International Nuclear Information System (INIS)

Cabal Rodriguez, Ana Ester

2004-11-01

This work presents the development and characterization of a single photon counting system based on silicon microstrip detectors, used in High Energy Physics experiments, and on low noise multichannel readout electronics. The thesis evaluates the feasibility of dual energy X-ray imaging with silicon microstrip detectors to be applied on medical diagnosis. Dual energy mammographic and angiographic experimental tests have been performed using the developed counting systems proto types, properly phantoms and quasi-monochromatic X ray beams, obtained on a compact dichromatic source based on a conventional X-ray tube and a mosaic crystal. A Monte Carlo simulation of the performance of the experimental setup for dual X-ray imaging has also been carried out using MCNP-4C transport code. We obtained good agreement between MCNP results and the experimental data. (Author)

Design and Analysis of a Triple Stop-band Filter Using Ratioed Periodical Defected Microstrip Structure

Science.gov (United States)

Jiang, Tao; Wang, Yanyan; Li, Yingsong

2017-07-01

In this paper, a triple stop-band filter with a ratioed periodical defected microstrip structure is proposed for wireless communication applications. The proposed ratioed periodical defected microstrip structures are spiral slots, which are embedded into a 50 Ω microstrip line to obtain multiple stop-bands. The performance of the proposed triple stop-band filter is investigated numerically and experimentally. Moreover, the equivalent circuit model of the proposed filter is also established and discussed. The results are given to verify that the proposed triple stop-band filter has three stop bands at 3.3 GHz, 5.2 GHz, 6.8 GHz to reject the unwanted signals, which is promising for integrating into UWB communication systems to efficiently prevent the potential interferences from unexpected narrowband signals such as WiMAX, WLAN and RFID communication systems.

P-spray implant optimization for the fabrication of n-in-p microstrip detectors

International Nuclear Information System (INIS)

Fleta, Celeste; Lozano, Manuel; Pellegrini, Giulio; Campabadal, Francesca; Rafi, Joan Marc; Ullan, Miguel

2007-01-01

This work reports on an optimization study of the p-spray profile for the fabrication of n-in-p microstrip silicon detectors. A thorough simulation process of the expected electrical performance of different p-spray technologies was carried out. The best technological options for the p-spray implantation were chosen for the fabrication of miniature n-in-p microstrip detectors on high resistivity FZ wafers at the IMB-CNM clean room. The main conclusions derived from the simulations, and the electrical performance of a sample of the fabricated devices is presented

Dismantling the silicon microstrip detector on L3

CERN Multimedia

Laurent Guiraud

2001-01-01

The silicon microstrip detector is located at the heart of the detector and must be kept cool to prevent thermal noise. The work shown here is the removal of the cooling system. L3 was dismantled as part of the closure of the entire LEP accelerator in 2000 to make way for the new LHC.

An UWB LNA Design with PSO Using Support Vector Microstrip Line Model

Directory of Open Access Journals (Sweden)

Salih Demirel

2015-01-01

Full Text Available A rigorous and novel design procedure is constituted for an ultra-wideband (UWB low noise amplifier (LNA by exploiting the 3D electromagnetic simulator based support vector regression machine (SVRM microstrip line model. First of all, in order to design input and output matching circuits (IMC-OMC, source ZS and load ZL termination impedance of matching circuit, which are necessary to obtain required input VSWR (Vireq, noise (Freq, and gain (GTreq, are determined using performance characterisation of employed transistor, NE3512S02, between 3 and 8 GHz frequencies. After the determination of the termination impedance, to provide this impedance with IMC and OMC, dimensions of microstrip lines are obtained with simple, derivative-free, easily implemented algorithm Particle Swarm Optimization (PSO. In the optimization of matching circuits, highly accurate and fast SVRM model of microstrip line is used instead of analytical formulations. ADCH-80a is used to provide ultra-wideband RF choking in DC bias. During the design process, it is aimed that Vireq = 1.85, Freq = Fmin, and GTreq = GTmax all over operating frequency band. Measurements taken from the realized LNA demonstrate the success of this approximation over the band.

Self-error-rejecting photonic qubit transmission in polarization-spatial modes with linear optical elements

Science.gov (United States)

Jiang, YuXiao; Guo, PengLiang; Gao, ChengYan; Wang, HaiBo; Alzahrani, Faris; Hobiny, Aatef; Deng, FuGuo

2017-12-01

We present an original self-error-rejecting photonic qubit transmission scheme for both the polarization and spatial states of photon systems transmitted over collective noise channels. In our scheme, we use simple linear-optical elements, including half-wave plates, 50:50 beam splitters, and polarization beam splitters, to convert spatial-polarization modes into different time bins. By using postselection in different time bins, the success probability of obtaining the uncorrupted states approaches 1/4 for single-photon transmission, which is not influenced by the coefficients of noisy channels. Our self-error-rejecting transmission scheme can be generalized to hyperentangled n-photon systems and is useful in practical high-capacity quantum communications with photon systems in two degrees of freedom.

A time projection chamber with microstrip read-out

International Nuclear Information System (INIS)

Bootsma, T.M.V.; Van den Brink, A.; De Haas, A.P.; Kamermans, R.; Kuijer, P.G.; De Laat, C.T.A.M.; Van Nieuwenhuizen, G.J.; Ostendorf, R.; Snellings, R.J.M.; Twenhoefel, C.J.W.; Peghaire, A.

1994-01-01

The design and testing of a novel detector for heavy-ion physics in the intermediate-energy regime is described. This detector consists of a large drift chamber with microstrip read-out in combination with thick plastic scintillators. With this system particle identification and energy determination with high spatial resolution and multiple hit capacity is achieved. ((orig.))

Gas microstrip detectors based on flexible printed circuit

International Nuclear Information System (INIS)

Salomon, M.; Crowe, K.; Faszer, W.; Lindsay, P.; Curran Maier, J.M.

1995-09-01

We have studied the properties of a new type of Gas Microstrip Counter built using flexible printed circuit technology. We describe the manufacturing procedures, the assembly of the device, as well as its operation under a variety of conditions, gases and types of radiation. We also describe two new passivation materials, Tantalum and Niobium, which produce effective surfaces. (author)

Full Ka Band Waveguide-to-Microstrip Inline Transition Design

Science.gov (United States)

Li, Jianxing; Li, Lei; Qiao, Yu; Chen, Juan; Chen, Jianzhong; Zhang, Anxue

2018-05-01

In this paper, a compact and broadband inline waveguide-to-microstrip transition is proposed to cover the full Ka band. The transition can be segmented from the electric point of view into three building blocks, comprising a microstrip line to rectangular coaxial line, a wedged rectangular coaxial line to ridged waveguide, and a final tapered ridged waveguide impedance transformer to standard waveguide. Both good electrical performance and simple modular assembly without any soldering have been simultaneously obtained. The validation of the design concept has been conducted by numerical simulations and experimental measurements. The experimental results of a fabricated back-to-back transition prototype coincide with the simulated results. It shows that the proposed transition achieves good return loss of lower than 15.5 dB and low insertion loss with a fluctuation between 0.23 to 0.60 dB across the entire Ka band. Details of design considerations and operation mechanism as well as simulation and measurement results are presented.

Design of Miniaturized Dual-Band Microstrip Antenna for WLAN Application

Science.gov (United States)

Yang, Jiachen; Wang, Huanling; Lv, Zhihan; Wang, Huihui

2016-01-01

Wireless local area network (WLAN) is a technology that combines computer network with wireless communication technology. The 2.4 GHz and 5 GHz frequency bands in the Industrial Scientific Medical (ISM) band can be used in the WLAN environment. Because of the development of wireless communication technology and the use of the frequency bands without the need for authorization, the application of WLAN is becoming more and more extensive. As the key part of the WLAN system, the antenna must also be adapted to the development of WLAN communication technology. This paper designs two new dual-frequency microstrip antennas with the use of electromagnetic simulation software—High Frequency Structure Simulator (HFSS). The two antennas adopt ordinary FR4 material as a dielectric substrate, with the advantages of low cost and small size. The first antenna adopts microstrip line feeding, and the antenna radiation patch is composed of a folded T-shaped radiating dipole which reduces the antenna size, and two symmetrical rectangular patches located on both sides of the T-shaped radiating patch. The second antenna is a microstrip patch antenna fed by coaxial line, and the size of the antenna is diminished by opening a stepped groove on the two edges of the patch and a folded slot inside the patch. Simulation experiments prove that the two designed antennas have a higher gain and a favourable transmission characteristic in the working frequency range, which is in accordance with the requirements of WLAN communication. PMID:27355954

Design of a power amplifier for wireless communications using microstrip technology and Microwave Office

Directory of Open Access Journals (Sweden)

Christian Tipantuña

2015-12-01

Full Text Available This paper provides a detailed description and all the procedures involved in designing a power amplifier using microstrip technology and the design software Microwave OfficeTM. Specifically, the design is oriented to build an amplifier with central frequency at 14 GHz, but the same fundamentals and principles could be applied in the whole range of radio frequency. For the design, a MESFET transistor and simultaneous input and output matching networks are considered. The values of the parameters and the simulation for every stage are computed and performed using AWR Microwave OfficeTM. At the end of the document, a fully functional circuit layout represented in 2D and 3D is shown with all their complementary elements

Development of Electromagnetic Band Gap Structures in the Perspective of Microstrip Antenna Design

Directory of Open Access Journals (Sweden)

Md. Shahidul Alam

2013-01-01

Full Text Available Electromagnetic band gap (EBG technology has become a significant breakthrough in the radio frequency (RF and microwave applications due to their unique band gap characteristics at certain frequency ranges. Since 1999, the EBG structures have been investigated for improving performances of numerous RF and microwave devices utilizing the surface wave suppression and the artificial magnetic conductor (AMC properties of these special type metamaterial. Issues such as compactness, wide bandwidth with low attenuation level, tunability, and suitability with planar circuitry all play an important role in the design of EBG structures. Remarkable efforts have been undertaken for the development of EBG structures to be compatible with a wide range of wireless communication systems. This paper provides a comprehensive review on various EBG structures such as three-, two-, and one-dimensional (3D, 2D, and 1D EBG, mushroom and uniplanar EBG, and their successive advancement. Considering the related fabrication complexities, implementation of vialess EBG is an attractive topic for microwave engineers. For microstrip antennas, EBG structures are used in diversified ways, which of course found to be effective except in some cases. The EBG structures are also successfully utilized in antenna arrays for reducing the mutual coupling between elements of the array. Current challenges and limitations of the typical microstrip antennas and different EBG structures are discussed in details with some possible suggestions. Hopefully, this survey will guide to increasing efforts towards the development of more compact, wideband, and high-efficient uniplanar EBG structures for performance enhancement of antenna and other microwave devices.

An Uncoventional Approach for a Straw Tube-Microstrip Detector

OpenAIRE

Basile, E.; Bellucci, F.; Benussi, L.; Bertani, M.; Bianco, S.; Caponero, M. A.; Colonna, D.; Di Falco, F.; Fabbri, F. L.; Felli, F.; Giardoni, M.; La Monaca, A.; Mensitieri, G.; Ortenzi, B.; Pallotta, M.

2004-01-01

We report on a novel concept of silicon microstrips and straw tubes detector, where integration is accomplished by a straw module with straws not subjected to mechanical tension in a Rohacell lattice and carbon fiber reinforced plastic shell. Results on mechanical and test beam performances are reported on as well.

Circularly Polarized Slotted Microstrip Patch Antenna with Finite Ground Plane

Directory of Open Access Journals (Sweden)

Sanyog Rawat

2012-12-01

Full Text Available In this paper a new geometry of circularly polarized patch antenna is proposed with improved bandwidth. The radiation performance of proposed patch antenna is investigated using IE3D simulation software and its performance is compared with that of conventional rectangular patch antenna. The simulated return loss, axial ratio and impedance with frequency for the proposed antenna are reported in this paper. It is shown that by selecting suitable ground-plane dimensions, air gap and location of the slots, the impedance bandwidth can be enhanced upto 10.15% as compared to conventional rectangular patch (4.24% with an axial ratio bandwidth of 4.05%.

Noise and signal processing in a microstrip detector with a time variant readout system

International Nuclear Information System (INIS)

Cattaneo, P.W.

1995-01-01

This paper treats the noise and signal processing by a time variant filter in a microstrip detector. In particular, the noise sources in the detector-electronics chain and the signal losses that cause a substantial decrease of the original signal are thoroughly analyzed. This work has been motivated by the analysis of the data of the microstrip detectors designed for the ALEPH minivertex detector. Hence, even if the discussion will be kept as general as possible, concrete examples will be presented referring to the specific ALEPH design. (orig.)

ATLAS silicon microstrip detector system (SCT)

International Nuclear Information System (INIS)

Unno, Y.

2003-01-01

The S CT together with the pixel and the transition radiation tracker systems and with a central solenoid forms the central tracking system of the ATLAS detector at LHC. Series production of SCT Silicon microstrip sensors is near completion. The sensors have been shown to be robust against high voltage operation to the 500 V required after fluences of 3x10 14 protons/cm 2 . SCT barrel modules are in series production. A low-noise CCD camera has been used to debug the onset of leakage currents

Temperature dependence of dynamical permeability characterization of magnetic thin films using shorted microstrip line probe

International Nuclear Information System (INIS)

Li, Xiling; Li, Chengyi; Chai, Guozhi

2017-01-01

A temperature dependence microwave permeability characterization system of magnetic thin film up to 10 GHz is designed and fabricated. This system can be used at temperatures ranging from room temperature to 200 °C, and is based on a shorted microstrip probe, which is made by microwave printed circuit board. Without contacting the magnetic thin films to the probe, the microwave permeability of the film can be detected without any limitations of sample size and with almost the same accuracy, as shown by comparison with the results obtained from a shorted microstrip transmission-line fixture. The complex permeability can be deduced by an analytical approach from the measured reflection coefficient of a strip line ( S 11 ) with and without a ferromagnetic film material on it. The procedures are the same with the shorted microstrip transmission-line method. The microwave permeability of an oblique deposited CoZr thin film was investigated with this probe. The results show that the room temperature dynamic permeability of the CoZr film is in good agreement with the results obtained from the established short-circuited microstrip perturbation method. The temperature dependence permeability results fit well with the Landau–Lifshitz–Gilbert equation. Development of the temperature-dependent measurement of the magnetic properties of magnetic thin film may be useful for the high-frequency application of magnetic devices at high temperatures. (paper)

Simply folded band chaos in a VHF microstrip oscillator

Energy Technology Data Exchange (ETDEWEB)

Blakely, Jonathan N. [US Army Research, Development, and Engineering Command, AMSRD-AMR-WS-ST, Redstone Arsenal, AL 35898 (United States)]. E-mail: jonathan.blakely@us.army.mil; Holder, J. Darryl [US Army Research, Development, and Engineering Command, AMSRD-AMR-WS-ST, Redstone Arsenal, AL 35898 (United States); Corron, Ned J. [US Army Research, Development, and Engineering Command, AMSRD-AMR-WS-ST, Redstone Arsenal, AL 35898 (United States); Pethel, Shawn D. [US Army Research, Development, and Engineering Command, AMSRD-AMR-WS-ST, Redstone Arsenal, AL 35898 (United States)

2005-10-10

We present experimental observations of a microstrip circuit that produces Roessler-like chaos with center frequency of 175 MHz. A simply folded band chaotic attractor is created through a period doubling route. The circuit provides an experimental realization of a chaotic neutral delay differential equation, a largely unexplored type of nonlinear dynamical system.

Linearity discontinuities in Xe-filled X-ray microstrip detectors

DEFF Research Database (Denmark)

Zavattini, G.; Feroci, M.; Budtz-Jørgensen, Carl

1997-01-01

A prototype Xe + 10% CH4 microstrip detector was used to study the K-edge discontinuity in the pulse-height distribution as a function of the energy of incident X-rays. The electronics used was such that a pulse-shape rejection could be made of K-fluorescence reabsorption in the detector. The mea...

Polarized light and optical measurement

CERN Document Server

Clarke, D N; Ter Haar, D

2013-01-01

Polarized Light and Optical Measurement is a five-chapter book that begins with a self-consistent conceptual picture of the phenomenon of polarization. Chapter 2 describes a number of interactions of light and matter used in devising optical elements in polarization studies. Specific optical elements are given in Chapter 3. The last two chapters explore the measurement of the state of polarization and the various roles played in optical instrumentation by polarization and polarization-sensitive elements. This book will provide useful information in this field of interest for research workers,

Substrate-induced instability in gas microstrip detectors

International Nuclear Information System (INIS)

Bateman, J.E.; Connolly, J.F.

1992-12-01

The results of a programme of research into substrate-induced gain instability in gas microstrip detectors are reported. Information has been collected on a wide range of substrates including many commonly available glasses and ceramics. A theoretical model of the gain instability is proposed. While we have not yet found an acceptable substrate for the construction of high flux detectors our experience points to electronically conductive glasses as the most promising source of a stable substrate. (Author)

CBC2: A CMS microstrip readout ASIC with logic for track-trigger modules at HL-LHC

Energy Technology Data Exchange (ETDEWEB)

Hall, G., E-mail: g.hall@imperial.ac.uk [Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom); Pesaresi, M.; Raymond, M. [Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom); Braga, D.; Jones, L.; Murray, P.; Prydderch, M. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 OQX (United Kingdom); Abbaneo, D.; Blanchot, G.; Honma, A.; Kovacs, M.; Vasey, F. [CERN, CH-1211, Geneva (Switzerland)

2014-11-21

The CBC2 is the latest version of the CMS Binary Chip ASIC for readout of the upgraded CMS Tracker at the High Luminosity LHC. It is designed in 130 nm CMOS with 254 input channels and will be bump-bonded to a substrate to which sensors will be wire-bonded. The CBC2 is designed to instrument double layer modules, consisting of two overlaid silicon microstrip sensors with aligned microstrips, in the outer tracker. It incorporates logic to identify L1 trigger primitives in the form of “stubs”: high transverse-momentum track candidates which are identified within the low momentum background by selecting correlated hits between two closely separated microstrip sensors. The first prototype modules have been assembled. The performance of the chip in recent laboratory tests is briefly reported and the status of module construction described.

Production of ALICE microstrip detectors at ITC-irst

International Nuclear Information System (INIS)

Gregori, Paolo; Bellutti, Pierluigi; Boscardin, Maurizio; Collini, Amos; Dalla Betta, Gian-Franco; Pucker, Georg; Zorzi, Nicola

2007-01-01

We report on the results from the production of 600 double-sided silicon microstrip detectors for the ALICE experiment. We present the fabrication process and some selected results from the electrical characterization of detectors and test structures. The large amount of experimental data allowed a statistically relevant analysis to be performed. The main technological aspects related to production yield optimization will also be addressed

Characterization procedures for double-sided silicon microstrip detectors

Energy Technology Data Exchange (ETDEWEB)

Bruner, N.L. [New Mexico Univ., Albuquerque, NM (United States). New Mexico Center for Particle Phys.; Frautschi, M.A. [New Mexico Univ., Albuquerque, NM (United States). New Mexico Center for Particle Phys.; Hoeferkamp, M.R. [New Mexico Univ., Albuquerque, NM (United States). New Mexico Center for Particle Phys.; Seidel, S.C. [New Mexico Univ., Albuquerque, NM (United States). New Mexico Center for Particle Phys.

1995-08-15

Since double-sided silicon microstrip detectors are still evolving technologically and are not yet commercially available, they require extensive electrical evaluation by the user to ensure they were manufactured to specifications. In addition, measurements must be performed to determine detector operating conditions. Procedures for measuring the following quantities are described: - Leakage current, - Depletion voltage, - Bias resistance, - Interstrip resistance, - Coupling capacitance, - Coupling capacitor breakdown voltage. (orig.).

Characterization procedures for double-sided silicon microstrip detectors

International Nuclear Information System (INIS)

Bruner, N.L.; Frautschi, M.A.; Hoeferkamp, M.R.; Seidel, S.C.

1995-01-01

Since double-sided silicon microstrip detectors are still evolving technologically and are not yet commercially available, they require extensive electrical evaluation by the user to ensure they were manufactured to specifications. In addition, measurements must be performed to determine detector operating conditions. Procedures for measuring the following quantities are described: - Leakage current, - Depletion voltage, - Bias resistance, - Interstrip resistance, - Coupling capacitance, - Coupling capacitor breakdown voltage. (orig.)

Ultraviolet-light-induced multi-physics behaviors of 0–3 polarized transparent PLZT plates: II. Finite element analysis and validation

International Nuclear Information System (INIS)

Luo, Quantian; Tong, Liyong

2011-01-01

This paper presents a novel finite element formulation for 0–3 polarized PbLaZrTi (PLZT) plates and a comparison of the predicted and measured bending displacements. The coupled multi-physics fields and Hamilton's principle for piezoelectric (PZT) materials are first extended to PLZT ceramics by including the anomalous photovoltaic and photo-thermal effects. The photo-induced non-uniform electrical field and mechanical strains across the thickness are modeled in the present finite element formulation for 0–3 polarized PLZT plates, and the associated actuator and sensor equations are derived. The transverse displacements of a 0–3 polarized PLZT plate are predicted using the present finite element formulation and compared with the measured data given in part I. A reasonably good correlation is noted for the transverse displacements at the ten measurement points

Intercomparison of Methods for Determination of Resonant Frequency Shift of a Microstrip Patch Antenna Loaded with Hevea Rubber Latex

Directory of Open Access Journals (Sweden)

Nor Zakiah Yahaya

2014-01-01

Full Text Available This paper presents an intercomparison between the finite element method, method of moment, and the variational method to determine the effect of moisture content on the resonant frequency shift of a microstrip patch loaded with wet material. The samples selected for this study were Hevea rubber latex with different percentages of moisture content from 35% to 85%. The results were compared with the measurement data in the frequency range between 1 GHz and 4 GHz. It was found that the finite element method is the most accurate among all the three computational techniques with 0.1 mean error when compared to the measured resonant frequency shift. A calibration equation was obtained to predict moisture content from the measured frequency shift with an accuracy of 2%.

Performance of microstrip and microgap gas detectors at high pressure

International Nuclear Information System (INIS)

Fraga, F.A.F.; Fraga, M.M.F.R.; Marques, R.F.; Margato, L.M.S.; Goncalo, J.R.; Policarpo, A.J.P.L.

1997-01-01

A study of the operation of microstrip and microgap detectors at various gas pressures up to 6 bar with Kr-CO 2 , Xe-CO 2 and Xe-CH 4 is presented. The data were collected with a microstrip (1000 μm pitch) and a microgap (200 μm pitch) detector using a clean chamber and gas system. It is shown that maximum gain is strongly dependent on pressure and gains as high as 9 x 10 3 were obtained with Kr-CO 2 at 6 bar with a MSGC. With the smaller-pitch MGC we could get a gain of 180 with Xe-CH 4 at 6 bar; the typical energy resolution at 22 keV being about 15%. From the present work one can conclude that microstructures can operate at high pressure and that their application in high-efficiency, low-granularity X-ray detectors with an energy range up to a few tens of keV can be seriously considered. (orig.)

Coherent quantum cascade laser micro-stripe arrays

Directory of Open Access Journals (Sweden)

G. M. de Naurois

2011-09-01

Full Text Available We have fabricated InP-based coherent quantum cascade laser micro-stripe arrays. Phase-locking is provided by evanescent coupling between adjacent stripes. Stripes are buried into semi-insulating iron doped InP. Lasing at room temperature is obtained at 8.4μm for stripe arrays comprising up to 16 emitters. Pure supermode emission is demonstrated via farfield measurements and simulations. The farfield pattern shows a dual-lobe emission, corroborating the predicted phase-locked antisymmetric supermode emission.

Beam tests with microstrip gas counters

International Nuclear Information System (INIS)

Landry, M.R.; Birchall, J.; Crow, K.; Davis, C.A.; Faszer, W.; Gan, L.; Lee, L.; van Oers, W.T.H.; Page, S.A.; Ramsay, W.D.; Salomon, M.

1994-10-01

We have measured the efficiency, timing and pulse heights in several types of microstrip Gas Chambers with plastic substrates passivated with a thin Nickel layer. We used as active gas mixtures Argon/Isobutane and CF 4 /Isobutane. We placed the detectors in a secondary beam at TRIUMF tuned to a momentum of 100 MeV/c of pions, muons and electrons. Preliminary results indicate good efficiency for minimum ionizing particles in Argon/Isobutane mixtures but lesser efficiency in CF 4 based gases indicating the importance of high quality preamplifiers to increase the signal to noise ratio. (author). 20 refs., 6 figs

Study of micro-strip gas ionisation chambers substrates for CMS experiment at LHC; Etude de substrats pour chambres gazeuses a micropistes dans le cadre de l`experience CMS au LHC

Energy Technology Data Exchange (ETDEWEB)

Pallares, A.

1996-06-14

High luminosity, expected interaction and dose rates of the future LHC collider require the development of micro-strips gas chambers. In addition to optimization of this new detector, this work is concerned with understanding of gain loss phenomena. Influence of the gas substrate is carefully analysed, as well as theoretical concepts concerning glasses and their behaviour under polarization and irradiation, and the consequence on detection operations.Electron spin resonance is used to study, in standard glass, creation of radiation induced defects which may be charged. (D.L.). 14 refs.

Size optimization for complex permeability measurement of magnetic thin films using a short-circuited microstrip line up to 30 GHz

Science.gov (United States)

Takeda, Shigeru; Naoe, Masayuki

2018-03-01

High-frequency permeability spectra of magnetic films were measured over a wideband frequency range of 0.1-30 GHz using a shielded and short-circuited microstrip line jig. In this measurement, spurious resonances had to be suppressed up to the highest frequency. To suppress these resonances, characteristic impedance of the microstrip line should approach 50 Ω at the junction between connector and microstrip line. The main factors dominating these resonances were structures of the jig and the sample. The dimensions were optimized in various experiments, and results demonstrated that the frequency could be raised to at least 20 GHz. For the transverse electromagnetic mode to transmit stably along the microstrip line, the preferred sample was rectangular, with the shorter side parallel to the line and the longer side perpendicular to it, and characteristic impedance strongly depended on the signal line width of the jig. However, too small a jig and sample led to a lower S/N ratio.

Wideband Dual-Polarization Patch Antenna Array With Parallel Strip Line Balun Feeding

DEFF Research Database (Denmark)

Zhang, Jin; Lin, Xianqi; Nie, Liying

2016-01-01

A wideband dual-polarization patch antenna array is proposed in this letter. The array is fed by a parallel strip line balun, which is adopted to generate 180° phase shift in a wide frequency range. In addition, this balun has simple structure, very small phase shift error, and good ports isolati...... is higher than 30 dB. The simulation and measurement turns out to be similar. This antenna array can be used in TD-LTE base stations, and the design methods are also useful to other wideband microstrip antennas....

A Novel Approach for an Integrated Straw Tube-Microstrip Detector

Science.gov (United States)

Basile, E.; Bellucci, F.; Benussi, L.; Bertani, M.; Bianco, S.; Caponero, M. A.; Colonna, D.; Di Falco, F.; Fabbri, F. L.; Felli, F.; Giardoni, M.; La Monaca, A.; Mensitieri, G.; Ortenzi, B.; Pallotta, M.; Paolozzi, A.; Passamonti, L.; Pierluigi, D.; Pucci, C.; Russo, A.; Saviano, G.; Casali, F.; Bettuzzi, M.; Bianconi, D.; Baruffaldi, F.; Perilli, E.; Massa, F.

2006-06-01

We report on a novel concept of silicon microstrips and straw tubes detector, where integration is accomplished by a straw module with straws not subjected to mechanical tension in a Rohacell/spl reg/ lattice and carbon fiber reinforced plastic shell. Results on mechanical and test beam performances are reported as well.

Analysis and optimal design of Si microstrip detector with overhanging metal electrode

CERN Document Server

Ranjan, Kirti; Chatterji, S; Srivastava-Ajay, K; Shivpuri, R K

2001-01-01

The harsh radiation environment to be encountered at LHC (large hadron collider) and RHIC (relativistic heavy ion collider) poses a challenging task for the fabrication of Si microstrip detectors. Due to high luminosities, detectors are required to sustain very high voltage operation well exceeding the bias voltage needed to fully deplete them. The "overhanging" metal contact is now a well established technique for improving the breakdown performance of the Si microstrip detector. Based on computer simulation, the influence of various physical and geometrical parameters on the electrical breakdown of the Si detectors equipped with metal overhangs is extensively analysed. Furthermore, optimization of design parameters is performed to achieve breakdown voltages close to maximum realizable values. The simulation results are found to be in good agreement with experimental data. (17 refs).

DESIGN OF MULTILAYER APERTURE COUPLED STACKED MICROSTRIP PATCH ANTENNA FOR WLAN APPLICATIONS

Directory of Open Access Journals (Sweden)

P. Jothilakshmi

2015-10-01

Full Text Available One of the major drawbacks of microstrip patch antenna is its narrow bandwidth. The solution of this problem is to use aperture coupled stacked micro strip patch antenna. The antenna uses a combination of aperture coupled feeding technique and multi- layer radiating patch in order for the radiating elements are increase the gain bandwidth. The ‘I’ and ‘H’ shaped aperture slots are etched onto the ground plane. It is used to transfer the energy from feed line to stacked patch. A variation of the feed line length controls the selected aperture slots to be active. The waves from the selected activated aperture slots will radiate to particular radiating patch and achieve the desired resonant frequency. The air gap is used to avoid coupling loss between the aperture slots and stacked patches. The observed simulated and measured results show that the proposed antenna structure resonated at 2.51 GHz frequency with reduced return loss and optimum voltage standing wave ratio.

Singularity Processing Method of Microstrip Line Edge Based on LOD-FDTD

Directory of Open Access Journals (Sweden)

Lei Li

2014-01-01

Full Text Available In order to improve the performance of the accuracy and efficiency for analyzing the microstrip structure, a singularity processing method is proposed theoretically and experimentally based on the fundamental locally one-dimensional finite difference time domain (LOD-FDTD with second-order temporal accuracy (denoted as FLOD2-FDTD. The proposed method can highly improve the performance of the FLOD2-FDTD even when the conductor is embedded into more than half of the cell by the coordinate transformation. The experimental results showed that the proposed method can achieve higher accuracy when the time step size is less than or equal to 5 times of that the Courant-Friedrich-Levy (CFL condition allowed. In comparison with the previously reported methods, the proposed method for calculating electromagnetic field near microstrip line edge not only improves the efficiency, but also can provide a higher accuracy.

Spatial resolution of wedge shaped silicon microstrip detectors

International Nuclear Information System (INIS)

Anticic, T.; Barnett, B.; Blumenfeld, B.; Chien, C.Y.; Fisher, P.; Gougas, A.; Krizmanic, J.; Madansky, L.; Newman, D.; Orndorff, J.; Pevsner, A.; Spangler, J.

1995-01-01

Several wedge-shaped silicon microstrip detectors with pitches from 30 to 100 μm have been designed by our group and beam tested at the CERN SPS. We find the spatial resolution σ becomes larger at the rate of 0.21 μm per 1 μm increase in pitch, but the number of strips per cluster remains about the same as the pitch varies from 30 to 100 μm. (orig.)

A Novel Approach for an Integrated Straw tube-Microstrip Detector

OpenAIRE

Basile, E.; Bellucci, F.; Benussi, L.; Bertani, M.; Bianco, S.; Caponero, M. A.; Colonna, D.; Di Falco, F.; Fabbri, F. L.; Felli, F.; Giardoni, M.; La Monaca, A.; Mensitieri, G.; Ortenzi, B.; Pallotta, M.

2005-01-01

We report on a novel concept of silicon microstrips and straw tubes detector, where integration is accomplished by a straw module with straws not subjected to mechanical tension in a Rohacell $^{\\circledR}$ lattice and carbon fiber reinforced plastic shell. Results on mechanical and test beam performances are reported on as well.

Development of Technique for Testing the Long-Term Stability of Silicon Microstrip Detectors

International Nuclear Information System (INIS)

Kosinov, A.V.; Maslov, N.I.; Naumov, S.V.; Ovchinnik, V.D.; Starodubtsev, A.F.; Vasiliev, G.P.; Yalovenko, V.I.; Bosisio, L.

2006-01-01

An automatic multi-channel set-up prototype for simultaneous testing of the Long-Term Stability (LTS) of more than ten detectors is described. The Inner Tracking System of the ALICE experiment will include about two thousand Double-sided Microstrip Detectors (DSMD). Efficient automatic measurement techniques are crucial for the LTS test, because the corresponding test procedure should be performed on each detector and requires long time, at least two days. By using special adapters for supporting and connecting the bare DSMDs, failing detectors can be screened out before module assembly, thus minimizing the cost. Automated probe stations developed for a special purpose or for microelectronics industry are used for measuring physical static DSMD characteristics and check good-to-bad elements ratio for DSMD. However, automated (or semi-automatic)test benches for studying LTS or testing DSMD long-term stability before developing a detecting module are absent

Open-Circuit End Effect of Microstrip Line Configuration in Plasma Medium

Directory of Open Access Journals (Sweden)

Prem Bhushan Mital

1996-01-01

Full Text Available The extension in length for open microstrip configuration in plasma media is determined using spectral domain technique under quasi static approach [1, 2]. The results were verified by modifying Hammerstad equation for plasma media. Good agreement is found between the two results.

Assembly and validation of the SSD silicon microstrip detector of ALICE

NARCIS (Netherlands)

de Haas, A.P.; Kuijer, P.G.; Nooren, G.J.L.; Oskamp, C.J.; Sokolov, A.N.; van den Brink, A.

2006-01-01

The Silicon Strip Detector (SSD) forms the two outermost layers of the Inner Tracking System (ITS) of ALICE. The SSD detector consists of 1698 double-sided silicon microstrip modules. The electrical connection between silicon sensor and front-end electronics is made via TAB-bonded

Quality Factor Effect on the Wireless Range of Microstrip Patch Antenna Strain Sensors

Directory of Open Access Journals (Sweden)

Ali Daliri

2014-01-01

Full Text Available Recently introduced passive wireless strain sensors based on microstrip patch antennas have shown great potential for reliable health and usage monitoring in aerospace and civil industries. However, the wireless interrogation range of these sensors is limited to few centimeters, which restricts their practical application. This paper presents an investigation on the effect of circular microstrip patch antenna (CMPA design on the quality factor and the maximum practical wireless reading range of the sensor. The results reveal that by using appropriate substrate materials the interrogation distance of the CMPA sensor can be increased four-fold, from the previously reported 5 to 20 cm, thus improving considerably the viability of this type of wireless sensors for strain measurement and damage detection.

Quality Factor Effect on the Wireless Range of Microstrip Patch Antenna Strain Sensors

Science.gov (United States)

Daliri, Ali; Galehdar, Amir; Rowe, Wayne S. T.; John, Sabu; Wang, Chun H.; Ghorbani, Kamran

2014-01-01

Recently introduced passive wireless strain sensors based on microstrip patch antennas have shown great potential for reliable health and usage monitoring in aerospace and civil industries. However, the wireless interrogation range of these sensors is limited to few centimeters, which restricts their practical application. This paper presents an investigation on the effect of circular microstrip patch antenna (CMPA) design on the quality factor and the maximum practical wireless reading range of the sensor. The results reveal that by using appropriate substrate materials the interrogation distance of the CMPA sensor can be increased four-fold, from the previously reported 5 to 20 cm, thus improving considerably the viability of this type of wireless sensors for strain measurement and damage detection. PMID:24451457

Analysis and design of broadband U-slot cut rectangular microstrip ...

Indian Academy of Sciences (India)

AMIT A DESHMUKH

2017-07-15

Jul 15, 2017 ... Abstract. Broadband microstrip antenna using variations of U-slot has been widely reported. However, in most of the reported work, an in-depth explanation about the mode introduced by U-slot and procedure to design. U-slot cut antennas at any given frequency is not explained. In this paper, first an ...

77 GHz MEMS antennas on high-resistivity silicon for linear and circular polarization

KAUST Repository

Sallam, M. O.

2011-07-01

Two new MEMS antennas operating at 77 GHz are presented in this paper. The first antenna is linearly polarized. It possesses a vertical silicon wall that carries a dipole on top of it. The wall is located on top of silicon substrate covered with a ground plane. The other side of the substrate carries a microstrip feeding network in the form of U-turn that causes 180 phase shift. This phase-shifter feeds the arms of the dipole antenna via two vertical Through-Silicon Vias (TSVs) that go through the entire wafer. The second antenna is circularly polarized and formed using two linearly polarized antennas spatially rotated with respect to each other by 90 and excited with 90 phase shift. Both antennas are fabricated using novel process flow on a single high-resistivity silicon wafer via bulk micromachining. Only three processing steps are required to fabricate these antennas. The proposed antennas have appealing characteristics, such as high polarization purity, high gain, and high radiation efficiency. © 2011 IEEE.

SPICE evaluation of the S/N ratio for Si microstrip detectors

International Nuclear Information System (INIS)

Candelori, A.; Paccagnella, A.; Nardi, F.; Bacchetta, N.; Bisello, D.

1999-01-01

SPICE simulations of ac-coupled single-sided Si microstrip detectors connected to the PreShape 32 read-out chip have been performed in order to determine the geometrical characteristics (i.e., the strip pitch p and width w) which maximize the signal-to-noise ratio. All of the resistive and capacitive elements of the detector have been determined as a function of the w/p ratio by considering experimental and simulated data available in literature. The SPICE model the authors propose in this work takes into account all the main noise sources in the detector and read-out electronics. The minimum ionizing particle current signal shape has been introduced in the simulations. Two read-out configurations (every strip or every second strip) have been investigated for 6.4- and 12.8-cm-long detectors. The equivalent noise charge as determined by the simulations has been compared with analytical calculations, in order to determine the limits and the corrections to a simplified analytical noise model. Finally, general guidelines for the detector design have been proposed, based on the simulation results

A Multiband Proximity-Coupled-Fed Flexible Microstrip Antenna for Wireless Systems

Directory of Open Access Journals (Sweden)

Giovanni Andrea Casula

2016-01-01

Full Text Available A multiband printed microstrip antenna for wireless communications is presented. The antenna is fed by a proximity-coupled microstrip line, and it is printed on a flexible substrate. The antenna has been designed using a general-purpose 3D computer-aided design software (CAD, CST Microwave Studio, and then realized. The comparison between simulated and measured results shows that the proposed antenna can be used for wireless communications for WLAN systems, covering both the WLAN S-band (2.45 GHz and C-band (5.2 GHz, and the Wi-Max 3.5 GHz band, with satisfactory input matching and broadside radiation pattern. Moreover, it has a compact size, is very easy to realize, and presents a discrete out-of-band rejection, without requiring the use of stop-band filters. The proposed structure can be used also as a conformal antenna, and its frequency response and radiated field are satisfactory for curvatures up to 65°.

Observation of electron multiplication in liquid xenon with a microstrip plate

International Nuclear Information System (INIS)

Policarpo, A.P.L.; Geltenbort, P.; Ferreira Marques, R.; Araujo, H.; Fraga, F.; Alves, M.A.; Fonte, P.; Lima, E.P.; Fraga, M.M.; Salete Leite, M.; Silander, K.; Onofre, A.; Pinhao, J.M.

1995-01-01

We report here on the observation of electron multiplication in liquid xenon in a microstrip chamber with an amplification factor of the order of 10. The measurements were carried out at a temperature between 208 and 215 K (liquid density of about 2.7 g/cm 3 ). (orig.)

Reduction of the In-Band RCS of Microstrip Patch Antenna by Using Offset Feeding Technique

Directory of Open Access Journals (Sweden)

Weiwei Xu

2014-01-01

Full Text Available This paper presents a method for implementing a low in-band scattering design for microstrip patch antennas based on the analysis of structural mode scattering and radiation characteristics. The antenna structure is first designed to have the lowest structural mode scattering in a desired frequency band. The operating frequency band of the antenna is then changed to coincide with that of the lowest structural mode scattering by adjusting the feed position on the antenna (offset feeding to achieve an antenna with low in-band radar cross section (RCS. In order to reduce the level of cross polarization of the antenna caused by offset feeding, symmetry feeding structures for both single patch antennas and two-patch arrays are proposed. Examples that show the efficiency of the method are given, and the results illustrate that the in-band RCS of the proposed antennas can be reduced by as much as 17 dBsm for plane waves impinging from the normal direction compared to patch antennas fed by conventional methods.

The bipolar silicon microstrip detector: A proposal for a novel precision tracking device

International Nuclear Information System (INIS)

Horisberger, R.

1990-01-01

It is proposed to combine the technology of fully depleted microstrip detectors fabricated on n doped high resistivity silicon with the concept of the bipolar transistor. This is done by adding a n ++ doped region inside the normal p + implanted region of the reverse biased p + n diode. The resulting structure has amplifying properties and is referred to as bipaolar pixel transistor. The simplest readout scheme of a bipolar pixel array by an aluminium strip bus leads to the bipolar microstrip detector. The bipolar pixel structure is expected to give a better signal-to-noise performance for the detection of minimum ionizing charged particle tracks than the normal silicon diode strip detector and therefore should allow in future the fabrication of thinner silicon detectors for precision tracking. (orig.)

Influence of carbon and lipid sources on variation of mercury and other trace elements in polar bears (Ursus maritimus).

Science.gov (United States)

Routti, Heli; Letcher, Robert J; Born, Erik W; Branigan, Marsha; Dietz, Rune; Evans, Thomas J; McKinney, Melissa A; Peacock, Elizabeth; Sonne, Christian

2012-12-01

In the present study, the authors investigated the influence of carbon and lipid sources on regional differences in liver trace element (As, Cd, Cu, total Hg, Mn, Pb, Rb, Se, and Zn) concentrations measured in polar bears (Ursus maritimus) (n = 121) from 10 Alaskan, Canadian Arctic, and East Greenland subpopulations. Carbon and lipid sources were assessed using δ(13) C in muscle tissue and fatty acid (FA) profiles in subcutaneous adipose tissue as chemical tracers. A negative relationship between total Hg and δ(13) C suggested that polar bears feeding in areas with higher riverine inputs of terrestrial carbon accumulate more Hg than bears feeding in areas with lower freshwater input. Mercury concentrations were also positively related to the FA 20:1n-9, which is biosynthesized in large amounts in Calanus copepods. This result raises the hypothesis that Calanus glacialis are an important link in the uptake of Hg in the marine food web and ultimately in polar bears. Unadjusted total Hg, Se, and As concentrations showed greater geographical variation among polar bear subpopulations compared with concentrations adjusted for carbon and lipid sources. The Hg concentrations adjusted for carbon and lipid sources in Bering-Chukchi Sea polar bear liver tissue remained the lowest among subpopulations. Based on these findings, the authors suggest that carbon and lipid sources for polar bears should be taken into account when one is assessing spatial and temporal trends of long-range transported trace elements. Copyright © 2012 SETAC.

Gas microstrip detectors on resistive plastic substrates

International Nuclear Information System (INIS)

Dixit, M.S.; Oakham, F.G.; Armitage, J.C.

1993-01-01

Plastics are desirable as substrates for gas microstrip detectors (GMDs) because of their flexibility, low density and long radiation length. GMDs have been fabricated on white Tedlar which has bulk electrical conductivity and ion-implanted Upilex which has a thin electrically conductive layer on the surface of an insulator. The effect of back plane voltage on the gain of such GMDs is investigated. Three 200 μm pitch, ion-implanted Upilex GMDs were recently tested in a high intensity beam at CERN. The anode signals were read out using fast, low noise, high gain amplifiers. Preliminary results of the test are presented

ATLAS Silicon Microstrip Tracker Operation and Performance

CERN Document Server

Yamada, M; The ATLAS collaboration

2011-01-01

The SemiConductor Tracker (SCT), comprising of silicon micro-strip detectors is one of the key precision tracking devices in the ATLAS Inner Detector. ATLAS is one of the experiments at CERN LHC. The completed SCT is in very good shapes with 99.3% of the SCT’s 4088 modules (a total of 6.3 million strips) are operational. The noise occupancy and hit efficiency exceed the design specifications. In the talk the current status of the SCT will be reviewed. We will report on the operation of the detector, its performance and observed problems, with stress on the sensor and electronics performance.

Note: Electrical detection and quantification of spin rectification effect enabled by shorted microstrip transmission line technique

International Nuclear Information System (INIS)

Soh, Wee Tee; Ong, C. K.; Peng, Bin; Chai, Guozhi

2014-01-01

We describe a shorted microstrip method for the sensitive quantification of Spin Rectification Effect (SRE). SRE for a Permalloy (Ni 80 Fe 20 ) thin film strip sputtered onto SiO 2 substrate is demonstrated. Our method obviates the need for simultaneous lithographic patterning of the sample and transmission line, therefore greatly simplifying the SRE measurement process. Such a shorted microstrip method can allow different contributions to SRE (anisotropic magnetoresistance, Hall effect, and anomalous Hall effect) to be simultaneously determined. Furthermore, SRE signals from unpatterned 50 nm thick Permalloy films of area dimensions 5 mm × 10 mm can even be detected

Gas microstrip detectors on polymer, silicon and glass substrates

International Nuclear Information System (INIS)

Barasch, E.F.; Demroff, H.P.; Drew, M.M.; Elliott, T.S.; Gaedke, R.M.; Goss, L.T.; Kasprowicz, T.B.; Lee, B.; Mazumdar, T.K.; McIntyre, P.M.; Pang, Y.; Smith, D.D.; Trost, H.J.; Vanstraelen, G.; Wahl, J.

1993-01-01

We present results on the performance of Gas Microstrip Detectors on various substrates. These include a 300 μm anode-anode pitch pattern on Tempax borosilicate glass and ABS/copolyether, a 200 μm pattern on Upilex ''S'' polyimide, Texin 4215, Tedlar, ion-implanted Kapton, orientation-dependent etched flat-topped silicon (''knife-edge chamber''), and iron-vanadium glass, and a 100 μm pitch pattern on Upilex ''S'' and ion-implanted Kapton. (orig.)

A microstrip gas avalanche chamber with two-dimensional readout

International Nuclear Information System (INIS)

Angelini, F.; Bellazzini, R.; Brez, A.; Massai, M.M.; Spandre, G.; Torquati, M.R.

1989-01-01

A microstrip gas avalanche chamber with a 200 μm anode pitch has been built and successfully tested in our laboratory. A gas gain of 10 4 and an energy resolution of 18% (FWHM) at 6 keV have been measured using a gas mixture of argon-CO 2 at atmospheric pressure. A preliminary measurement of the positional sensitivity indicates that a spatial resolution of 50 μm can be obtained. (orig.)

Microstrip Patch Sensor for Salinity Determination.

Science.gov (United States)

Lee, Kibae; Hassan, Arshad; Lee, Chong Hyun; Bae, Jinho

2017-12-18

In this paper, a compact microstrip feed inset patch sensor is proposed for measuring the salinities in seawater. The working principle of the proposed sensor depends on the fact that different salinities in liquid have different relative permittivities and cause different resonance frequencies. The proposed sensor can obtain better sensitivity to salinity changes than common sensors using conductivity change, since the relative permittivity change to salinity is 2.5 times more sensitive than the conductivity change. The patch and ground plane of the proposed sensor are fabricated by conductive copper spray coating on the masks made by 3D printer. The fabricated patch and the ground plane are bonded to a commercial silicon substrate and then attached to 5 mm-high chamber made by 3D printer so that it contains only 1 mL seawater. For easy fabrication and testing, the maximum resonance frequency was selected under 3 GHz and to cover salinities in real seawater, it was assumed that the salinity changes from 20 to 35 ppt. The sensor was designed by the finite element method-based ANSYS high-frequency structure simulator (HFSS), and it can detect the salinity with 0.01 ppt resolution. The designed sensor has a resonance frequency separation of 37.9 kHz and reflection coefficients under -20 dB at the resonant frequencies. The fabricated sensor showed better performance with average frequency separation of 48 kHz and maximum reflection coefficient of -35 dB. By comparing with the existing sensors, the proposed compact and low-cost sensor showed a better detection capability. Therefore, the proposed patch sensor can be utilized in radio frequency (RF) tunable sensors for salinity determination.

DUAL POLARIZATION ANTENNA ARRAY WITH VERY LOW CROSS POLARIZATION AND LOW SIDE LOBES

DEFF Research Database (Denmark)

1997-01-01

The present invention relates to an antenna array adapted to radiate or receive electromagnetic waves of one or two polarizations with very low cross polarization and low side lobes. An antenna array comprising many antenna elements, e.g. more than ten antenna elements, is provided in which...... formation of grating lobes are inhibited in selected directions of the radiation and cross polarization within the main lobe is suppressed at least 30 dB below the main lobe peak value. According to a preferred embodiment of the invention, the antenna elements of the antenna array comprise probe-fed patches...

Cross-talk studies on FPCB of double-sided silicon micro-strip detector

International Nuclear Information System (INIS)

Yang, Lei; Li, Zhankui; Li, Haixia; Wang, Pengfei; Wang, Zhusheng; Chen, Cuihong; Liu, Fengqiong; Li, Ronghua; Wang, Xiuhua; Li, Chunyan; Zu, Kailing

2014-01-01

Double-sided silicon micro-strip detector's parameters and a test method and the results of cross-talk of FPCB are given in this abstract. In addition, the value of our detector's readout signal has little relation to FPCB's cross-talk.

Study of Silicon Microstrip Detector Properties for the LHCb Silicon Tracker

CERN Document Server

Lois-Gómez, C; Vázquez-Regueiro, P

2006-01-01

The LHCb experiment, at present under construction at the Large Hadron Collider at CERN, has been designed to perform high-precision measurements of CP violating phenomena and rare decays in the B meson systems. The need of a good tracking performance and the high density of particles close to the beam pipe lead to the use of silicon microstrip detectors in a significant part of the LHCb tracking system. The Silicon Tracker (ST) will be built using p-on-n silicon detectors with strip pitches of approximately 200 $\\mu$m and readout strips up to 38 cm in length. This thesis describes the tests carried out on silicon microstrip detectors for the ST, starting from the characterization of different prototypes up to the final tests on the detectors that are being installed at CERN. The results can be divided in three main blocks. The first part comprises an exhaustive characterization of several prototype sensors selected as suitable candidates for the detector and was performed in order to decide some design param...

Microstrip linear phase low pass filter based on defected ground structures for partial response modulation

DEFF Research Database (Denmark)

Cimoli, Bruno; Johansen, Tom Keinicke; Olmos, Juan Jose Vegas

2018-01-01

We report a high performance linear phase low pass filter (LPF) designed for partial response (PR) modulations. For the implementation, we adopted microstrip technology and a variant of the standard stepped‐impedance technique. Defected ground structures (DGS) are used for increasing the characte......We report a high performance linear phase low pass filter (LPF) designed for partial response (PR) modulations. For the implementation, we adopted microstrip technology and a variant of the standard stepped‐impedance technique. Defected ground structures (DGS) are used for increasing...... the characteristic impedance of transmission lines. Experimental results prove that the proposed filter can successfully modulate a non‐return‐to‐zero (NRZ) signal into a five levels PR one....

A radiographic imaging system based upon a 2-D silicon microstrip sensor

CERN Document Server

Papanestis, A; Corrin, E; Raymond, M; Hall, G; Triantis, F A; Manthos, N; Evagelou, I; Van den Stelt, P; Tarrant, T; Speller, R D; Royle, G F

2000-01-01

A high resolution, direct-digital detector system based upon a 2-D silicon microstrip sensor has been designed, built and is undergoing evaluation for applications in dentistry and mammography. The sensor parameters and image requirements were selected using Monte Carlo simulations. Sensors selected for evaluation have a strip pitch of 50mum on the p-side and 80mum on the n-side. Front-end electronics and data acquisition are based on the APV6 chip and were adapted from systems used at CERN for high-energy physics experiments. The APV6 chip is not self-triggering so data acquisition is done at a fixed trigger rate. This paper describes the mammographic evaluation of the double sided microstrip sensor. Raw data correction procedures were implemented to remove the effects of dead strips and non-uniform response. Standard test objects (TORMAX) were used to determine limiting spatial resolution and detectability. MTFs were determined using the edge response. The results indicate that the spatial resolution of the...

Factors influencing the performances of micro-strips gas chambers

International Nuclear Information System (INIS)

Mack, V.; Brom, J.M.; Fang, R.; Fontaine, J.C.; Huss, D.; Kachelhoffer, T.; Kettunen, H.; Levy, J.M.; Pallares, A.; Bergdolt, A.M.; Cailleret, J.; Christophel, E.; Coffin, J.; Eberle, H.; Osswald, F.; Sigward, M.H.

1995-01-01

Damages to MSGCs (Micro-Strips Gas Chambers) induced by discharges have been investigated. Optimization of electrode shapes and/or deposition of a protective coating allows the potential difference between anode and cathode, thus increasing the gain. For prototypes of MSGCs made at the Centre de Recherches Nucleaires, each step of the manufacturing processes was carefully controlled. Results are presented on the influence of cleaning processes on the surface resistance of glass substrates. (author). 21 refs., 8 figs., 2 tabs

Performance of a silicon microstrip detector in a high radiation environment

International Nuclear Information System (INIS)

Mishra, C.S.; Brown, C.N.; Kapustinsky, J.; Leitch, M.J.; McGaughey, P.L.; Peng, J.C.; Sailor, W.; Holzscheiter, K.; Sadler, M.

1990-01-01

This paper reports on the performance of a silicon microstrip detector that has been studied in a high rate environment using electron, pion, and proton beams. The pulse height, time response, and leakage current have been studied as a function of particle fluence up to a total integrated flus of about 4 x 10 14 protons/cm 2

Modelling of bow-tie microstrip antennas using modified locally conformal FDTD method

NARCIS (Netherlands)

George, J.

2000-01-01

An analysis of bow-tie microstrip antennas is presented based on the use of the modified locally conformal finite-difference time-domain (FDTD) method. This approach enables the number of cells along the antenna length and width to be chosen independently of the antenna central width, which helps to

Systematic characterization and quality assurance of silicon micro-strip sensors for the Silicon Tracking System of the CBM experiment

Science.gov (United States)

Ghosh, P.

2014-07-01

The Silicon Tracking System (STS) is the central detector of the Compressed Baryonic Matter (CBM) experiment at future Facility for Anti-proton and Ion Research (FAIR) at Darmstadt. The task of the STS is to reconstruct trajectories of charged particles originating at relatively high multiplicities from the high rate beam-target interactions. The tracker comprises of 300 μm thick silicon double-sided micro-strip sensors. These sensors should be radiation hard in order to reconstruct charged particles up to a maximum radiation dose of 1 × 1014neqcm-2. Systematic characterization allows us to investigate the sensor response and perform quality assurance (QA) tests. In this paper, systematic characterization of prototype double-sided silicon micro-strip sensors will be discussed. This procedure includes visual, passive electrical, and radiation hardness test. Presented results include tests on three different prototypes of silicon micro-strip sensors.

Systematic characterization and quality assurance of silicon micro-strip sensors for the Silicon Tracking System of the CBM experiment

International Nuclear Information System (INIS)

Ghosh, P

2014-01-01

The Silicon Tracking System (STS) is the central detector of the Compressed Baryonic Matter (CBM) experiment at future Facility for Anti-proton and Ion Research (FAIR) at Darmstadt. The task of the STS is to reconstruct trajectories of charged particles originating at relatively high multiplicities from the high rate beam-target interactions. The tracker comprises of 300 μm thick silicon double-sided micro-strip sensors. These sensors should be radiation hard in order to reconstruct charged particles up to a maximum radiation dose of 1 × 10 14 n eq cm −2 . Systematic characterization allows us to investigate the sensor response and perform quality assurance (QA) tests. In this paper, systematic characterization of prototype double-sided silicon micro-strip sensors will be discussed. This procedure includes visual, passive electrical, and radiation hardness test. Presented results include tests on three different prototypes of silicon micro-strip sensors

Spatial and temporal trends of selected trace elements in liver tissue from polar bears (Ursus maritimus) from Alaska, Canada and Greenland.

Science.gov (United States)

Routti, Heli; Letcher, Robert J; Born, Erik W; Branigan, Marsha; Dietz, Rune; Evans, Thomas J; Fisk, Aaron T; Peacock, Elizabeth; Sonne, Christian

2011-08-01

Spatial trends and comparative changes in time of selected trace elements were studied in liver tissue from polar bears from ten different subpopulation locations in Alaska, Canadian Arctic and East Greenland. For nine of the trace elements (As, Cd, Cu, Hg, Mn, Pb, Rb, Se and Zn) spatial trends were investigated in 136 specimens sampled during 2005-2008 from bears from these ten subpopulations. Concentrations of Hg, Se and As were highest in the (northern and southern) Beaufort Sea area and lowest in (western and southern) Hudson Bay area and Chukchi/Bering Sea. In contrast, concentrations of Cd showed an increasing trend from east to west. Minor or no spatial trends were observed for Cu, Mn, Rb and Zn. Spatial trends were in agreement with previous studies, possibly explained by natural phenomena. To assess temporal changes of Cd, Hg, Se and Zn concentrations during the last decades, we compared our results to previously published data. These time comparisons suggested recent Hg increase in East Greenland polar bears. This may be related to Hg emissions and/or climate-induced changes in Hg cycles or changes in the polar bear food web related to global warming. Also, Hg:Se molar ratio has increased in East Greenland polar bears, which suggests there may be an increased risk for Hg(2+)-mediated toxicity. Since the underlying reasons for spatial trends or changes in time of trace elements in the Arctic are still largely unknown, future studies should focus on the role of changing climate and trace metal emissions on geographical and temporal trends of trace elements.

ATLAS silicon microstrip Semiconductor Tracker (SCT)

International Nuclear Information System (INIS)

Unno, Y.

2000-01-01

Silicon microstrip semiconductor tracking system (SCT) will be in operation in the ATLAS detector in the Large Hadron Collider (LHC) at CERN. Challenging issues in the SCT are the radiation tolerance to the fluence of 2x10 14 1-MeV-neutron-equivalent particles/cm 2 at the designed luminosity of 1x10 34 cm -2 /s of the proton-proton collisions and the speed of the electronics to identify the crossing bunches at 25 ns. The developments and the status of the SCT are presented from the point of view of these issues. Series production of the SCT will start in the year 2001 and the SCT will be installed into the ATLAS detector during 2003-2004

Effect of Feed Substrate Thickness on the Bandwidth and Radiation Characteristics of an Aperture-Coupled Microstrip Antenna with a High Permittivity Feed Substrate

Directory of Open Access Journals (Sweden)

Jae-Hyun Kim

2018-04-01

Full Text Available The impedance bandwidth and radiation characteristics of an aperture-coupled microstrip line-fed patch antenna (ACMPA with a high permittivity (ɛr = 10 feed substrate suitable for integration with a monolithic microwave integrated circuit (MMIC are investigated for various feed substrate thicknesses through an experiment and computer simulation. The impedance bandwidth of an ACMPA with a high permittivity feed substrate increases as the feed substrate thickness decreases. Furthermore, the front-to-back ratio of an ACMPA with a high permittivity feed substrate increases and the cross-polarization level decreases as the feed substrate thickness decreases. As the impedance bandwidth of an ACMPA with a high permittivity feed substrate increases and its radiation characteristics improve as the feed substrate thickness decreases, the ACMPA configuration becomes suitable for integration with an MMIC.

Circularly Polarized Antenna Array Fed by Air-Bridge Free CPW-Slotline Network

Directory of Open Access Journals (Sweden)

Yilin Liu

2017-01-01

Full Text Available A novel design of 1×2 and 2×2 circularly polarized (CP microstrip patch antenna arrays is presented in this paper. The two CP antenna arrays are fed by sequentially rotated coplanar waveguide (CPW to slotline networks and are processed on 1 mm thick single-layer FR4 substrates. Both of the two arrays are low-profile and lightweight. An air-bridge free CPW-slotline power splitter is appropriately designed to form the feeding networks and realize the two CP antenna arrays. The mechanism of circular polarization in this design is explained. The simulated and measured impedance bandwidths as well as the 3 dB axial ratio bandwidths and the radiation patterns of the two proposed antenna arrays are presented. This proposed design can be easily extended to form a larger plane array with good performance owing to its simple structure.

Microstrip Antenna Design for Femtocell Coverage Optimization

Directory of Open Access Journals (Sweden)

Afaz Uddin Ahmed

2014-01-01

Full Text Available A mircostrip antenna is designed for multielement antenna coverage optimization in femtocell network. Interference is the foremost concern for the cellular operator in vast commercial deployments of femtocell. Many techniques in physical, data link and network-layer are analysed and developed to settle down the interference issues. A multielement technique with self-configuration features is analyzed here for coverage optimization of femtocell. It also focuses on the execution of microstrip antenna for multielement configuration. The antenna is designed for LTE Band 7 by using standard FR4 dielectric substrate. The performance of the proposed antenna in the femtocell application is discussed along with results.

Performance of microstrip gas chambers passivated by thin semiconducting glass and plastic films

International Nuclear Information System (INIS)

Bishai, M.R.; Gerndt, E.K.E.; Shipsey, I.P.J.; Wang, P.N.; Bagulya, A.V.; Grishin, V.M.; Negodaev, M.A.; Geltenbort, P.

1995-01-01

Patterned microstrip gas chamber substrates have been covered with ion-beam sputtered glass with electronic conductivity or a polymer which was subsequently irradiated with an ion-beam. The sputtering procedure is described in detail. The performance of several detectors is reported. (orig.)

Energy resolution in X-ray detecting micro-strip gas counters

CERN Document Server

Bateman, J E; Derbyshire, G E; Duxbury, D M; Mir, J A; Spill, E J; Stephenson, R

2002-01-01

Systematic measurements of the energy resolution available from a Micro-Strip Gas Counter (MSGC) are presented. The effect of factors such as bias potential, gas filling and strip geometry on the energy resolution are examined in detail and related to a simple model. The geometry of the MSGC is adapted to permit 'wall-less' detection of X-rays and this results in useful improvements in the pulse height spectra.

Gas microstrip detectors for X-ray tomographic flow imaging

CERN Document Server

Key, M J; Luggar, R D; Kundu, A

2003-01-01

A investigation into the suitability of gas microstrip detector technology for a high-speed industrial X-ray tomography system is reported. X-ray energies in the region 20-30 keV are well suited to the application, which involves imaging two-dimensional slices through gas/liquid multiphase pipeline flows for quantitative component fraction measurement. Stable operation over a period representing several hundred individual tomographic scans at gas gains of 500 is demonstrated using a Penning gas mixture of krypton/propylene.

Microstrip Patch Sensor for Salinity Determination

Directory of Open Access Journals (Sweden)

Kibae Lee

2017-12-01

Full Text Available In this paper, a compact microstrip feed inset patch sensor is proposed for measuring the salinities in seawater. The working principle of the proposed sensor depends on the fact that different salinities in liquid have different relative permittivities and cause different resonance frequencies. The proposed sensor can obtain better sensitivity to salinity changes than common sensors using conductivity change, since the relative permittivity change to salinity is 2.5 times more sensitive than the conductivity change. The patch and ground plane of the proposed sensor are fabricated by conductive copper spray coating on the masks made by 3D printer. The fabricated patch and the ground plane are bonded to a commercial silicon substrate and then attached to 5 mm-high chamber made by 3D printer so that it contains only 1 mL seawater. For easy fabrication and testing, the maximum resonance frequency was selected under 3 GHz and to cover salinities in real seawater, it was assumed that the salinity changes from 20 to 35 ppt. The sensor was designed by the finite element method-based ANSYS high-frequency structure simulator (HFSS, and it can detect the salinity with 0.01 ppt resolution. The designed sensor has a resonance frequency separation of 37.9 kHz and reflection coefficients under −20 dB at the resonant frequencies. The fabricated sensor showed better performance with average frequency separation of 48 kHz and maximum reflection coefficient of −35 dB. By comparing with the existing sensors, the proposed compact and low-cost sensor showed a better detection capability. Therefore, the proposed patch sensor can be utilized in radio frequency (RF tunable sensors for salinity determination.

Spatial and temporal trends of selected trace elements in liver tissue from polar bears (Ursus maritimus) from Alaska, Canada and Greenland

Science.gov (United States)

Routti, H.; Letcher, R.J.; Born, E.W.; Branigan, M.; Dietz, R.; Evans, T.J.; Fisk, A.T.; Peacock, E.; Sonne, C.

2011-01-01

Spatial trends and comparative changes in time of selected trace elements were studied in liver tissue from polar bears from ten different subpopulation locations in Alaska, Canadian Arctic and East Greenland. For nine of the trace elements (As, Cd, Cu, Hg, Mn, Pb, Rb, Se and Zn) spatial trends were investigated in 136 specimens sampled during 2005-2008 from bears from these ten subpopulations. Concentrations of Hg, Se and As were highest in the (northern and southern) Beaufort Sea area and lowest in (western and southern) Hudson Bay area and Chukchi/Bering Sea. In contrast, concentrations of Cd showed an increasing trend from east to west. Minor or no spatial trends were observed for Cu, Mn, Rb and Zn. Spatial trends were in agreement with previous studies, possibly explained by natural phenomena. To assess temporal changes of Cd, Hg, Se and Zn concentrations during the last decades, we compared our results to previously published data. These time comparisons suggested recent Hg increase in East Greenland polar bears. This may be related to Hg emissions and/or climate-induced changes in Hg cycles or changes in the polar bear food web related to global warming. Also, Hg:Se molar ratio has increased in East Greenland polar bears, which suggests there may be an increased risk for Hg 2+-mediated toxicity. Since the underlying reasons for spatial trends or changes in time of trace elements in the Arctic are still largely unknown, future studies should focus on the role of changing climate and trace metal emissions on geographical and temporal trends of trace elements. ?? 2011 The Royal Society of Chemistry.

CBC3: a CMS microstrip readout ASIC with logic for track-trigger modules at HL-LHC

CERN Document Server

Prydderch, Mark Lyndon; Bell, Stephen Jean-marc; Key-Charriere, M; Jones, Lawrence; Auzinger, Georg; Borg, Johan; Hall, Geoffrey; Pesaresi, Mark Franco; Raymond, David Mark; Uchida, Kirika; Goldstein, Joel; Seif El Nasr, Sarah

2018-01-01

The CBC3 is the latest version of the CMS Binary Chip ASIC for readout of the outer radial region of the upgraded CMS Tracker at HL-LHC. This 254-channel, 130nm CMOS ASIC is designed to be bump-bonded to a substrate to which sensors will be wire-bonded. It will instrument double-layer 2S-modules, consisting of two overlaid silicon microstrip sensors with aligned microstrips. On-chip logic identifies first level trigger primitives from high transverse-momentum tracks by selecting correlated hits in the two sensors. Delivered in late 2016, the CBC3 has been under test for several months, including X-ray irradiations and SEU testing. Results and performance are reported.

High gain gas microstrip detectors for soft x-ray detection

International Nuclear Information System (INIS)

Bateman, J.; Barlow, R.; Derbyshire, G.

2001-01-01

This report describes development work in which systematic changes in the pitch of the electrode pattern of a Gas Microstrip Detector are explored in the search for higher avalanche gains and enhanced stability. With the cathode width set to half of the pitch, gas gains of >50 000 are comfortably attainable with low detector noise so that x-rays can potentially be detected down to the limit of a single x-ray-produced photoelectron. (author)

Microstripes for transport and separation of magnetic particles

DEFF Research Database (Denmark)

Donolato, Marco; Dalslet, Bjarke Thomas; Hansen, Mikkel Fougt

2012-01-01

We present a simple technique for creating an on-chip magnetic particle conveyor based on exchange-biased permalloy microstripes. The particle transportation relies on an array of stripes with a spacing smaller than their width in conjunction with a periodic sequence of four different externally...... applied magnetic fields. We demonstrate the controlled transportation of a large population of particles over several millimeters of distance as well as the spatial separation of two populations of magnetic particles with different magnetophoretic mobilities. The technique can be used for the controlled...... selective manipulation and separation of magnetically labelled species. (C) 2012 American Institute of Physics....

Performance of microstrip proportional counters for x-ray astronomy on spectrum-roentgen-gamma

DEFF Research Database (Denmark)

Budtz-Jørgensen, Carl; BAHNSEN, A; Christensen, Finn Erland

1991-01-01

DSRI will provide a set of four imaging proportional counters for the Danish-Soviet X-ray telescopes XSPECT/SODART. The sensor principle is based on the novel micro-strip proportional counter (MSPC), where the strip electrodes are deposited by photolithography onto a rigid substrate. The MSPC off...

Wideband, Low-Profile, Dual-Polarized Slot Antenna with an AMC Surface for Wireless Communications

Directory of Open Access Journals (Sweden)

Wei Hu

2016-01-01

Full Text Available A wideband dual-polarized slot antenna loaded with artificial magnetic conductor (AMC is proposed for WLAN/WIMAX and LTE applications. The slot antenna mainly consists of two pairs of arrow-shaped slots along the diagonals of the square patch. Stepped microstrip feedlines are placed orthogonally to excite the horizontal and vertical polarizations of the antenna. To realize unidirectional radiation and low profile, an AMC surface composed of 7 × 7 unit cells is designed underneath a distance of 0.09λ0 (λ0 being the wavelength in free space at 2.25 GHz from the slot antenna. Both the dual-polarized slot antenna and the AMC surface are fabricated and measured. Experimental results demonstrate that the proposed antenna achieves for both polarizations a wide impedance bandwidth (return loss 10 dB of 36.7%, operating from 1.96 to 2.84 GHz. The isolation between the two input ports keeps higher than 29 dB whereas the cross-polarization levels basically maintain lower than −30 dB across the entire frequency band. High front-to-back ratios better than 22 dB and a stable gain higher than 8 dBi are obtained over the whole band.

A Si nanocube array polarizer

Science.gov (United States)

Chen, Linghua; Jiang, Yingjie; Xing, Li; Yao, Jun

2017-10-01

We have proposed a full dielectric (silicon) nanocube array polarizer based on a silicon dioxide substrate. Each polarization unit column includes a plurality of equal spaced polarization units. By optimizing the length, the width, the height of the polarization units and the center distance of adjacent polarization unit (x direction and y direction), an extinction ratio (ER) of higher than 25dB was obtained theoretically when the incident light wavelength is 1550nm. while for applications of most polarization optical elements, ER above 10dB is enough. With this condition, the polarizer we designed can work in a wide wavelength range from 1509.31nm to 1611.51nm. Compared with the previous polarizer, we have introduced a polarizer which is a full dielectric device, which solves the problems of low efficiency caused by Ohmic loss and weak coupling. Furthermore, compared with the existing optical polarizers, our polarizer has the advantages of thin thickness, small size, light weight, and low processing difficulty, which is in line with the future development trend of optical elements.

Development of gas micro-strip chambers for high rate radiation detection and tracking

CERN Document Server

Bouclier, Roger; Gaudaen, J; Florent, J J; Ropelewski, Leszek; Sauli, Fabio; Bondar, A E; Groshev, V R; Minakov, G D; Onuchin, A P; Pestov, Yu N; Shekhtman, L I; Sidorov, V A; Dixit, M S; Oakham, G K; Møller, S; Sørensen, G; Uggerhøj, Erik; Brons, S; Brückner, W; Godbersen, M; Heidrich, M; Paul, S; Trombini, A; Werding, R; Armitage, J A; Karlen, D A; Stewart, G; Barasch, E F; McIntyre, P; Pang, Y; Trost, H J; Salomon, M; Breskin, Amos; Chechik, R; Pansky, A; CERN. Geneva. Detector Research and Development Committee

1992-01-01

Gas Micro-Strip Chambers (GMSC) are a promising high-rate, high resolution position detector suited for use in high luminosity hadron collider experiments, as general purpose tracker or to improve the performances of pre-shower counters, transition radiation and inner muon detectors. Large GMSC arrays have been included in proposed LHC and SSC experimental setups. The operating characteristics of GMSC make their use very attractive also for detectors at tau/charm/beauty factories, as well as for synchrotron radiation facilities and for medical applications. At the present state of the art, some problems limiting the usefulness of microstrip chambers are the observed gain changes due to charging up of the support, possible long-term degradation due to ageing, limited sizes imposed by fabrication technologies and unavailability of dedicated high-speed, high-density readout electronics. Limited experience exists of operation of GMSC in real experimental conditions, and little if anything is known about performan...

Technology development of p-type microstrip detectors with radiation hard p-spray isolation

International Nuclear Information System (INIS)

Pellegrini, G.; Fleta, C.; Campabadal, F.; Diez, S.; Lozano, M.; Rafi, J.M.; Ullan, M.

2006-01-01

A technology for the fabrication of p-type microstrip silicon radiation detectors using p-spray implant isolation has been developed at CNM-IMB. The p-spray isolation has been optimized in order to withstand a gamma irradiation dose up to 50 Mrad (Si), which represents the ionization radiation dose expected in the middle region of the SCT-Atlas detector of the future Super-LHC during 10 years of operation. The best technological options for the p-spray implant were found by using a simulation software package and dedicated calibration runs. Using the optimized technology, detectors have been fabricated in the Clean Room facility of CNM-IMB, and characterized by reverse current and capacitance measurements before and after irradiation. The average full depletion voltage measured on the non-irradiated detectors was V FD =41±3 V, while the leakage current density for the microstrip devices at V FD +20 V was 400 nA/cm 2

Influences of optical elements on the polarization measurement

International Nuclear Information System (INIS)

Goto, M.; Hayakawa, M.; Atake, M.; Iwamae, A.

2004-01-01

An emission line of He I λ 667.8 nm is observed and the Large Helical Device (LHD) with a polarimeter, with which two linearly polarized components if the light from the same line of sight is simultaneously measured. The emission line exhibits splitting due to the normal Zeeman effect and the π and σ lights are respectively observed. The results indicate the polarization state of emission lines is different from our expectation. From two measurements, for the second of which the polarimeter is rotated 45 degrees form the first, the polarization ellipses of all the three polarized lights are determined. Some observations for a reversed magnetic field plasma operation, for different emission lines of different ions, and also for operation with some different magnetic field strengths suggest that the distortion state originates not in the atomic radiation itself or the plasma condition, but in the optical window at the observation port of the vacuum chamber. (author)

Modeling dynamic exchange of gaseous elemental mercury at polar sunrise.

Science.gov (United States)

Dastoor, Ashu P; Davignon, Didier; Theys, Nicolas; Van Roozendael, Michel; Steffen, Alexandra; Ariya, Parisa A

2008-07-15

At polar sunrise, gaseous elemental mercury (GEM) undergoes an exceptional dynamic exchange in the air and at the snow surface during which GEM can be rapidly removed from the atmosphere (the so-called atmospheric mercury depletion events (AMDEs)) as well as re-emitted from the snow within a few hours to days in the Polar Regions. Although high concentrations of total mercury in snow following AMDEs is well documented, there is very little data available on the redox transformation processes of mercury in the snow and the fluxes of mercury at the air/snow interface. Therefore, the net gain of mercury in the Polar Regions as a result of AMDEs is still an open question. We developed a new version of the global mercury model, GRAHM, which includes for the first time bidirectional surface exchange of GEM in Polar Regions in spring and summer by developing schemes for mercury halogen oxidation, deposition, and re-emission. Also for the first time, GOME satellite data-derived boundary layer concentrations of BrO have been used in a global mercury model for representation of halogen mercury chemistry. Comparison of model simulated and measured atmospheric concentrations of GEM at Alert, Canada, for 3 years (2002-2004) shows the model's capability in simulating the rapid cycling of mercury during and after AMDEs. Brooks et al. (1) measured mercury deposition, reemission, and net surface gain fluxes of mercury at Barrow, AK, during an intensive measurement campaign for a 2 week period in spring (March 25 to April 7, 2003). They reported 1.7, 1.0 +/- 0.2, and 0.7 +/- 0.2 microg m(-2) deposition, re-emission, and net surface gain, respectively. Using the optimal configuration of the model, we estimated 1.8 microg m(-2) deposition, 1.0 microg m(-2) re-emission, and 0.8 microg m(-2) net surface gain of mercury for the same time period at Barrow. The estimated net annual accumulation of mercury within the Arctic Circle north of 66.5 degrees is approximately 174 t with +/-7 t of

Impact of band structure and transition matrix elements on polarization properties of the photoluminescence of semipolar and nonpolar InGaN quantum wells

Energy Technology Data Exchange (ETDEWEB)

Schade, L.; Schwarz, U.T. [Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79108 Freiburg (Germany); Fraunhofer Institute for Applied Solid State Physics (IAF), Tullastrasse 72, 79108 Freiburg (Germany); Wernicke, T. [Institute of Solid State Physics, Technical University, Hardenbergstrasse 36, 10623 Berlin (Germany); Weyers, M. [Ferdinand-Braun-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Strasse 4, 12489 Berlin (Germany); Kneissl, M. [Institute of Solid State Physics, Technical University, Hardenbergstrasse 36, 10623 Berlin (Germany); Ferdinand-Braun-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Strasse 4, 12489 Berlin (Germany)

2011-03-15

Partial or full linear polarization is characteristic for the spontaneous emission of light from semipolar and nonpolar InGaN quantum wells. This property is an implication of the crystalline anisotropy as a basic property of the wurtzite structure. The influence of this anisotropy on the band structure and the transition matrix elements was calculated by a k.p-method for arbitrary quantum well orientations with respect to the c-axis; results are shown here in detail. Optical polarization is a direct consequence of a broken symmetry, mainly affecting the transition matrix elements from the conduction to the valence bands. Furthermore, the strain of the InGaN quantum well strongly depends on the crystal orientation of the substrate, resulting in a valence band mixing. The composition of the eigenfunctions has emerged to be most important for the polarization dependence of strained semipolar and nonpolar InGaN QW. The matrix elements, in combination with the thermal occupation of the bands, determine the polarization of the spontaneously emitted light. Our photoluminescence measurements of nonpolar QW match well with this model. However, in contrast to calculations with standard band parameters, the two topmost subbands show a larger separation in the emitted energy. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

CPW-Fed Wideband Circular Polarized Antenna for UHF RFID Applications

Directory of Open Access Journals (Sweden)

Sun-Woong Kim

2017-01-01

Full Text Available We propose a wide bandwidth antenna with a circular polarization for universal Ultra High Frequency (UHF radio-frequency identification (RFID reader applications. To achieve a wide 3 dB axial ratio (AR bandwidth, three T-shaped microstrip lines are inserted into the ground plane. The measured impedance bandwidth of the proposed antenna is 480 MHz and extends from 660 to 1080 MHz, and the 3 dB AR bandwidth is 350 MHz and extends from 800 to 1155 MHz. The radiation pattern is a bidirectional pattern with a maximum antenna gain of 3.67 dBi. The overall size of the proposed antenna is 114 × 114 × 0.8 mm3.

Modelado de secciones curvas con tecnología microstrip

OpenAIRE

Aires Casas, Fco. Manuel

2008-01-01

El fin de algunos dispositivos electrónicos es ocupar el menor espacio posible, sin que la calidad de su función se devalúe apreciablemente, y para conseguirlo es necesario utilizar técnicas de miniaturización. Así, el objetivo principal del proyecto es analizar el efecto que tienen diferentes tipos de curvas en estructuras microstrip (líneas de transmisión constituidas por una franja conductora y un plano de tierra separados por un medio dieléctrico). El proceso se ha efectuado m...

Strip defect recognition in electrical tests of silicon microstrip sensors

Energy Technology Data Exchange (ETDEWEB)

Valentan, Manfred, E-mail: valentan@mpp.mpg.de

2017-02-11

This contribution describes the measurement procedure and data analysis of AC-coupled double-sided silicon microstrip sensors with polysilicon resistor biasing. The most thorough test of a strip sensor is an electrical measurement of all strips of the sensor; the measured observables include e.g. the strip's current and the coupling capacitance. These measurements are performed to find defective strips, e.g. broken capacitors (pinholes) or implant shorts between two adjacent strips. When a strip has a defect, its observables will show a deviation from the “typical value”. To recognize and quantify certain defects, it is necessary to determine these typical values, i.e. the values the observables would have without the defect. As a novel approach, local least-median-of-squares linear fits are applied to determine these “would-be” values of the observables. A least-median-of-squares fit is robust against outliers, i.e. it ignores the observable values of defective strips. Knowing the typical values allows to recognize, distinguish and quantify a whole range of strip defects. This contribution explains how the various defects appear in the data and in which order the defects can be recognized. The method has been used to find strip defects on 30 double-sided trapezoidal microstrip sensors for the Belle II Silicon Vertex Detector, which have been measured at the Institute of High Energy Physics, Vienna (Austria).

Prediction of matching condition for a microstrip subsystem using artificial neural network and adaptive neuro-fuzzy inference system

Science.gov (United States)

Salehi, Mohammad Reza; Noori, Leila; Abiri, Ebrahim

2016-11-01

In this paper, a subsystem consisting of a microstrip bandpass filter and a microstrip low noise amplifier (LNA) is designed for WLAN applications. The proposed filter has a small implementation area (49 mm2), small insertion loss (0.08 dB) and wide fractional bandwidth (FBW) (61%). To design the proposed LNA, the compact microstrip cells, an field effect transistor, and only a lumped capacitor are used. It has a low supply voltage and a low return loss (-40 dB) at the operation frequency. The matching condition of the proposed subsystem is predicted using subsystem analysis, artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS). To design the proposed filter, the transmission matrix of the proposed resonator is obtained and analysed. The performance of the proposed ANN and ANFIS models is tested using the numerical data by four performance measures, namely the correlation coefficient (CC), the mean absolute error (MAE), the average percentage error (APE) and the root mean square error (RMSE). The obtained results show that these models are in good agreement with the numerical data, and a small error between the predicted values and numerical solution is obtained.

Neutron beam test of multi-grid-type microstrip gas chamber

International Nuclear Information System (INIS)

Fujita, K.; Takahashi, H.; Siritiprussamee, P.; Niko, H.; Kai, M.; Nakazawa, M.; Ino, T.; Sato, S.; Yokoo, T.; Furusaka, M.; Kanazawa, M.

2006-01-01

Multi-grid-type microstrip gas chambers (M-MSGCs) are being developed for the next-generation pulsed neutron source. Two new concepts, a global-local-grouping (GLG) method and a graded cathode pattern readout method, were applied to the M-MSGC design for realizing higher counting rate than traditional 3 He proportional counters. One-dimensional detectors with 700 mm-long test plates were fabricated and tested with X-ray and neutron beams, which demonstrated position detection capability based on these concepts

Development of Gas Micro-Strip Chambers for Radiation Detection and Tracking at High Rates

CERN Multimedia

2002-01-01

% RD28 \\\\ \\\\ Micro-Strip Gas Chambers (GMSC) are a promising high rate, high resolution position detector suited for use in high luminosity hadron collider experiments, as general purpose tracker or to improve the performances of preshower counters, transition radiation and inner muon detectors. Large GMSC arrays have been included in proposed LHC and SSC experimental setups. The operating characteristics of GMSC make their use very attractive also for detectors at tau/beauty/charm factories, as well as for synchrotron radiation facilities and medical applications. At the present state of the art, some problems limiting the usefulness of microstrip chambers are the observed gain changes due to charging up of the support, possible long-term degradation due to ageing, limited sizes imposed by fabrication technologies and unavailability of dedicated high-speed, high-density readout electronics. Limited experience exists of operation of GMSC in real experimental conditions, and little if anything is known about p...

Development of a High-Stability Microstrip-based L-band Radiometer for Ocean Salinity Measurements

Science.gov (United States)

Pellerano, Fernando A.; Horgan, Kevin A.; Wilson, William J.; Tanner, Alan B.

2004-01-01

The development of a microstrip-based L-band Dicke radiometer with the long-term stability required for future ocean salinity measurements to an accuracy of 0.1 psu is presented. This measurement requires the L-band radiometers to have calibration stabilities of less than or equal to 0.05 K over 2 days. This research has focused on determining the optimum radiometer requirements and configuration to achieve this objective. System configuration and component performance have been evaluated with radiometer test beds at both JPL and GSFC. The GSFC testbed uses a cryogenic chamber that allows long-term characterization at radiometric temperatures in the range of 70 - 120 K. The research has addressed several areas including component characterization as a function of temperature and DC bias, system linearity, optimum noise diode injection calibration, and precision temperature control of components. A breadboard radiometer, utilizing microstrip-based technologies, has been built to demonstrate this long-term stability.

Development of a fabrication technology for double-sided AC-coupled silicon microstrip detectors

International Nuclear Information System (INIS)

Dalla Betta, G.-F.; Boscardin, M.; Bosisio, L.; Rachevskaia, I.; Zen, M.; Zorzi, N.

2001-01-01

We report on the development of a fabrication technology for double-sided, AC-coupled silicon microstrip detectors for tracking applications. Two batches of detectors with good electrical figures and a low defect rate were successfully manufactured at IRST Laboratory. The processing techniques and the experimental results obtained from these detector prototypes are presented and discussed

Microstrip Resonator for High Field MRI with Capacitor-Segmented Strip and Ground Plane

DEFF Research Database (Denmark)

Zhurbenko, Vitaliy; Boer, Vincent; Petersen, Esben Thade

2017-01-01

) segmenting stripe and ground plane of the resonator with series capacitors. The design equations for capacitors providing symmetric current distribution are derived. The performance of two types of segmented resonators are investigated experimentally. To authors’ knowledge, a microstrip resonator, where both......, strip and ground plane are capacitor-segmented, is shown here for the first time....

Performance of the ALIBAVA portable readout system with irradiated and non-irradiated microstrip silicon sensors

International Nuclear Information System (INIS)

Marco-Hernadez, R.

2009-01-01

A readout system for microstrip silicon sensors has been developed as a result of collaboration among the University of Liverpool, the CNM of Barcelona and the IFIC of Valencia. The name of this collaboration is ALIBAVA and it is integrated in the RD50 Collaboration. This system is able to measure the collected charge in one or two microstrip silicon sensors by reading out all the channels of the sensor(s), up to 256, as an analogue measurement. The system uses two Beetle chips to read out the detector(s). The Beetle chip is an analogue pipelined readout chip used in the LHCb experiment. The system can operate either with non-irradiated and irradiated sensors as well as with n-type and p-type microstrip silicon sensors. Heavily irradiated sensors will be used at the SLHC, so this system is being to research the performance of microstrip silicon sensors in conditions as similar as possible to the SLHC operating conditions. The system has two main parts: a hardware part and a software part. The hardware part acquires the sensor signals either from external trigger inputs, in case of a radioactive source setup is used, or from a synchronised trigger output generated by the system, if a laser setup is used. This acquired data is sent by USB to be stored in a PC for a further processing. The hardware is a dual board based system. The daughterboard is a small board intended for containing two Beetle readout chips as well as fan-ins and detector support to interface the sensors. The motherboard is intended to process the data, to control the whole hardware and to communicate with the software by USB. The software controls the system and processes the data acquired from the sensors in order to store it in an adequate format file. The main characteristics of the system will be described. Results of measurements acquired with n-type and p-type irradiated and non-irradiated detectors using both the laser and the radioactive source setup will be also presented and discussed

High flux operation of microstrip gas chambers on glass and plastic supports

International Nuclear Information System (INIS)

Bouclier, R.; Florent, J.J.; Gaudaen, J.; Millon, G.; Pasta, A.; Ropelewski, L.; Sauli, F.; Shekhtman, L.I.

1992-01-01

Recent observations on microstrip gas chambers realized on various glass and plastic supports are presented in this paper. Short term measurements indicate a rate capability up to and above 5x10 5 counts/s mm 2 . A long term exposure to radiation shows however gain modifications, dependent on the resistivity of the chamber substrate; a choice of low resistivity supports minimizes this effect. (orig.)

The ATLAS Silicon Microstrip Tracker

CERN Document Server

Haefner, Petra

2010-01-01

In December 2009 the ATLAS experiment at the CERN Large Hadron Collider (LHC) recorded the first proton-proton collisions at a centre-of-mass energy of 900 GeV. This was followed by collisions at the unprecedented energy of 7 TeV in March 2010. The SemiConductor Tracker (SCT) is a precision tracking device in ATLAS made up from silicon micro-strip detectors processed in the planar p-in-n technology. The signal from the strips is processed in the front-end ASICs working in binary readout mode. Data is transferred to the off-detector readout electronics via optical fibers. The completed SCT has been installed inside the ATLAS experiment. Since then the detector was operated for two years under realistic conditions. Calibration data has been taken and analysed to determine the performance of the system. In addition, extensive commissioning with cosmic ray events has been performed both with and without magnetic field. The sensor behaviour in magnetic field was studied by measurements of the Lorentz angle. After ...

Performance of microstrip gas chambers in BNL-E885: a search for LAMBDA LAMBDA-hypernuclei

CERN Document Server

Landry, M; Davis, C A; Faszer, W; Gan, L; Lee, L; Page, S A; Ramsay, W D; Salomon, M; Oers, W T H

1999-01-01

The performance of MicroStrip Gas Chambers (MSGC) in BNL Experiment 885, a search for LAMBDA LAMBDA-hypernuclei, is detailed. Chambers with an active area of 80x50 mm sup 2 were instrumented and operated as a vertex detector in the experiment. Furthermore, two distinct types of microstrip prints were utilized in these chambers. Prints manufactured with Integrated Circuit (IC) photolithographic technology have fine tolerances and thin minimum trace widths, but can suffer from a high rate of defects per print and are more costly. Prints constructed with Printed Circuit (PC) photolithographic technology have coarser tolerances but relatively few defects per print, and are extremely cost-effective. Results of bench and beam tests of both IC and PC based MSGCs are presented and their performance in BNL-E885 is discussed. E885 marks the first use of PC based MSGCs in an experiment.

Array elements for a DBS flat-plate antenna

Science.gov (United States)

Maddocks, M. C. D.

1988-07-01

The introduction of a direct broadcast by satellite (DBS) television service requires suitable receiving antennas to be available. An alternative to the parabolic dish antenna is a flat-plate antenna. The overall design of a circularly-polarized flat-plate antenna which can be mounted flat on the wall of a building has been considered in a companion Report. In this Report various types of elements are investigated and their advantages and disadvantages discussed. The most suitable element for use in a flat-plate array is identified as a linearly-polarized folded-dipole element; its performance is reported here. Linearly-polarized elements are found to perform better than circularly-polarized elements and could be used with a polarization converter to receive the circularly-polarized radiation that would be transmitted by DBS.

Snaps to Connect Coaxial and Microstrip Lines in Wearable Systems

Directory of Open Access Journals (Sweden)

Tiiti Kellomäki

2012-01-01

Full Text Available Commercial snaps (clothing fasteners can be used to connect a coaxial cable to a microstrip line. This is useful in the context of wearable antennas, especially in consumer applications and disposable connections. The measured S-parameters of the transition are presented, and an equivalent circuit and approximate equations are derived for system design purposes. The proposed connection is usable up to 1.5 GHz (10 dB return loss condition, and the frequency range can be extended to 2 GHz if a thinner, more flexible coaxial cable is used.

A micro-strip gas counter test with the RD20 front-end

International Nuclear Information System (INIS)

Clergeau, J.F.; Contardo, D.; Haroutunian, R.; Smadja, G.

1994-05-01

A Micro-Strip Gas Counter equipped with the VLSI preamplifier of the RD20 chip has been tested with minimum ionizing particles. The measured pulse shape and the signal to noise ratio are presented. The time resolution of the detector is compared for the Ar/DME and DME/CO 2 gas mixtures. Three methods for the bunch crossing identification at LHC are discussed. (authors). 5 refs., 7 figs., 3 tabs

Gain Enhancement of a Microstrip Patch Antenna Using a Reflecting Layer

Directory of Open Access Journals (Sweden)

Anwer Sabah Mekki

2015-01-01

Full Text Available A low profile, unidirectional, dual layer, and narrow bandwidth microstrip patch antenna is designed to resonate at 2.45 GHz. The proposed antenna is suitable for specific applications, such as security and military systems, which require a narrow bandwidth and a small antenna size. This work is mainly focused on increasing the gain as well as reducing the size of the unidirectional patch antenna. The proposed antenna is simulated and measured. According to the simulated and measured results, it is shown that the unidirectional antenna has a higher gain and a higher front to back ratio (F/B than the bidirectional one. This is achieved by using a second flame retardant layer (FR-4, coated with an annealed copper of 0.035 mm at both sides, with an air gap of 0.04λ0 as a reflector. A gain of 5.2 dB with directivity of 7.6 dBi, F/B of 9.5 dB, and −18 dB return losses (S11 are achieved through the use of a dual substrate layer of FR-4 with a relative permittivity of 4.3 and a thickness of 1.6 mm. The proposed dual layer microstrip patch antenna has an impedance bandwidth of 2% and the designed antenna shows very low complexity during fabrication.

Problem-Matched Basis Functions for Microstrip Coupled Slot Antennas based on Transmission Line Greens Functions

NARCIS (Netherlands)

Bruni, S.; Llombart Juan, N.; Neto, A.; Gerini, G.; Maci, S.

2004-01-01

A general algorithm for the analysis of microstrip coupled leaky wave slot antennas was discussed. The method was based on the construction of physically appealing entire domain Methods of Moments (MoM) basis function that allowed a consistent reduction of the number of unknowns and of total

A new method based on low background instrumental neutron activation analysis for major, trace and ultra-trace element determination in atmospheric mineral dust from polar ice cores

Energy Technology Data Exchange (ETDEWEB)

Baccolo, Giovanni, E-mail: giovanni.baccolo@mib.infn.it [Graduate School in Polar Sciences, University of Siena, Via Laterina 8, 53100, Siena (Italy); Department of Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano (Italy); INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Clemenza, Massimiliano [INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Department of Physics, University of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Delmonte, Barbara [Department of Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano (Italy); Maffezzoli, Niccolò [Centre for Ice and Climate, Niels Bohr Institute, Juliane Maries Vej, 30, 2100, Copenhagen (Denmark); Nastasi, Massimiliano; Previtali, Ezio [INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Department of Physics, University of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Prata, Michele; Salvini, Andrea [LENA, University of Pavia, Pavia (Italy); Maggi, Valter [Department of Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano (Italy); INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy)

2016-05-30

Dust found in polar ice core samples present extremely low concentrations, in addition the availability of such samples is usually strictly limited. For these reasons the chemical and physical analysis of polar ice cores is an analytical challenge. In this work a new method based on low background instrumental neutron activation analysis (LB-INAA) for the multi-elemental characterization of the insoluble fraction of dust from polar ice cores is presented. Thanks to an accurate selection of the most proper materials and procedures it was possible to reach unprecedented analytical performances, suitable for ice core analyses. The method was applied to Antarctic ice core samples. Five samples of atmospheric dust (μg size) from ice sections of the Antarctic Talos Dome ice core were prepared and analyzed. A set of 37 elements was quantified, spanning from all the major elements (Na, Mg, Al, Si, K, Ca, Ti, Mn and Fe) to trace ones, including 10 (La, Ce, Nd, Sm, Eu, Tb, Ho, Tm, Yb and Lu) of the 14 natural occurring lanthanides. The detection limits are in the range of 10{sup −13}–10{sup −6} g, improving previous results of 1–3 orders of magnitude depending on the element; uncertainties lies between 4% and 60%. - Highlights: • A new method based on neutron activation for the multi-elemental characterization of atmospheric dust entrapped in polar ice cores is proposed. • 37 elements were quantified in μg size dust samples with detection limits ranging from 10{sup −13} to 10{sup −6} g. • A low background approach and a clean analytical protocol improved INAA performances to unprecedented levels for multi-elemental analyses.

Dual Polarized Monopole Patch Antennas for UWB Applications with Elimination of WLAN Signals

Directory of Open Access Journals (Sweden)

P. Kumar

2016-05-01

Full Text Available This paper presents the design, fabrication and measurement of dual polarized microstrip patch antennas for ultra wideband (UWB applications with notch at 5-6 GHz band. The proposed antenna rejects the wireless local area network (WLAN signals and work properly in the entire remaining ultra-wideband. Two antennas are designed for two different frequency bands of ultra wideband and both antennas together produce the entire ultra wideband with notch at 5-6 GHz band. The antennas are fed by a 50 coaxial probe and the entire design is optimized using CST Microwave Studio. The bandwidth of 3.1-5 GHz is achieved by the optimized design of Antenna-1 and the bandwidth of 6 -10.6 GHz is achieved by the optimized design of Antenna-2. The bandwidth of the optimized combined antenna is 3.1-10.6 GHz with elimination of the 5-6 GHz band. Both antennas are simulated, developed and measured. The simulated and measured results are presented. The two designed dual polarized antennas i.e. Antenna-1 and Antenna-2 can be used for 3.1-5 GHz band and 6-10.6 GHz band dual polarized applications, respectively, and the combined antenna structure can be used for UWB dual polarized applications with elimination of 5-6 GHz band signals.

Passivation of gas microstrip detectors and stability of long-term operation

International Nuclear Information System (INIS)

Salomon, M.; Armitage, J.; Chapman, G.; Dixit, M.; Dubeau, J.; Faszer, W.; Hamel, L.A.; Oakham, G.

1994-01-01

We have studied the long-term operation of gas microstrip detectors which have been passivated with a layer of nickel oxide. We have used as the active gas CF 4 /isobutane (80 : 20) and three different types of substrates: Tedlar, glass and Upilex. In all three cases we found that the detectors are stable after passivation and can operate for a month without changes in gain at rates of MHz. The total accumulated charge was approximately 100 mC. ((orig.))

Study of lead free ferroelectrics using overlay technique on thick film microstrip ring resonator

Directory of Open Access Journals (Sweden)

Shridhar N. Mathad

2016-03-01

Full Text Available The lead free ferroelectrics, strontium barium niobates, were synthesized via the low cost solid state reaction method and their fritless thick films were fabricated by screen printing technique on alumina substrate. The X band response (complex permittivity at very high frequencies of Ag thick film microstrip ring resonator perturbed with strontium barium niobates (SrxBa1-xNb2O6 in form of bulk and thick film was measured. A new approach for determination of complex permittivity (ε′ and ε′′ in the frequency range 8–12 GHz, using perturbation of Ag thick film microstrip ring resonator (MSRR, was applied for both bulk and thick film of strontium barium niobates (SrxBa1-xNb2O6. The microwave conductivity of the bulk and thick film lie in the range from 1.779 S/cm to 2.874 S/cm and 1.364 S/cm to 2.296 S/cm, respectively. The penetration depth of microwave in strontium barium niobates is also reported.

Ultrahigh frequency tunability of aperture-coupled microstrip antenna via electric-field tunable BST

Science.gov (United States)

Du, Hong-Lei; Xue, Qian; Gao, Xiao-Yang; Yao, Feng-Rui; Lu, Shi-Yang; Wang, Ye-Long; Liu, Chun-Heng; Zhang, Yong-Cheng; Lü, Yue-Guang; Li, Shan-Dong

2015-12-01

A composite ceramic with nominal composition of 45.0 wt%(Ba0.5Sr0.5)TiO3-55.0 wt%MgO (acronym is BST-MgO) is sintered for fabricating a frequency reconfigurable aperture-coupled microstrip antenna. The calcined BST-MgO composite ceramic exhibits good microwave dielectric properties at X-band with appropriate dielectric constant ɛr around 85, lower dielectric loss tan δ about 0.01, and higher permittivity tunability 14.8% at 8.33 kV/cm. An ultrahigh E-field tunability of working frequency up to 11.0% (i.e., from 9.1 GHz to 10.1 GHz with a large frequency shift of 1000 MHz) at a DC bias field from 0 to 8.33 kV/cm and a considerably large center gain over 7.5 dB are obtained in the designed frequency reconfigurable microstrip antenna. These results demonstrate that BST materials are promising for the frequency reconfigurable antenna. Project supported by the National Natural Science Foundation of China (Grant No. 11074040) and the Key Project of Shandong Provincial Department of Science and Technology, China (Grant No. ZR2012FZ006).

Bandwidth enhancement of a dual band planar monopole antenna using meandered microstrip feeding.

Science.gov (United States)

Ahsan, M R; Islam, M T; Habib Ullah, M; Misran, N

2014-01-01

A meandered-microstrip fed circular shaped monopole antenna loaded with vertical slots on a high dielectric material substrate (ε r = 15) is proposed in this paper. The performance criteria of the proposed antenna have been experimentally verified by fabricating a printed prototype. The experimental results show that the proposed antenna has achieved wider bandwidth with satisfactory gain by introducing meandered-microstrip feeding in assistant of partial ground plane. It is observed that, the -10 dB impedance bandwidth of the proposed antenna at lower band is 44.4% (600 MHz-1 GHz) and at upper band is 28% (2.25 GHz-2.95 GHz). The measured maximum gains of -1.18 dBi and 4.87 dBi with maximum radiation efficiencies have been observed at lower band and upper band, respectively. The antenna configuration and parametric study have been carried out with the help of commercially available computer-aided EM simulator, and a good accordance is perceived in between the simulated and measured results. The analysis of performance criteria and almost consistent radiation pattern make the proposed antenna a suitable candidate for UHF RFID, WiMAX, and WLAN applications.

Microstrip Butler matrix design and realization for 7 T MRI.

Science.gov (United States)

Yazdanbakhsh, Pedram; Solbach, Klaus

2011-07-01

This article presents the design and realization of 8 × 8 and 16 × 16 Butler matrices for 7 T MRI systems. With the focus on low insertion loss and high amplitude/phase accuracy, the microstrip line integration technology (microwave-integrated circuit) was chosen for the realization. Laminate material of high permittivity (ε(r) = 11) and large thickness (h = 3.2 mm) is shown to allow the best trade-off of circuit board size versus insertion loss, saving circuit area by extensive folding of branch-line coupler topology and meandering phase shifter and connecting strip lines and reducing mutual coupling of neighboring strip lines by shield structures between strip lines. With this approach, 8 × 8 Butler matrices were produced in single boards of 310 mm × 530 mm, whereas the 16 × 16 Butler matrices combined two submatrices of 8 × 8 with two smaller boards. Insertion loss was found at 0.73 and 1.1 dB for an 8 × 8 matrix and 16 × 16 matrix, respectively. Measured amplitude and phase errors are shown to represent highly pure mode excitation with unwanted modes suppressed by 40 and 35 dB, respectively. Both types of matrices were implemented with a 7 T MRI system and 8- and 16-element coil arrays for RF mode shimming experiments and operated successfully with 8 kW of RF power. Copyright © 2011 Wiley-Liss, Inc.

Metamaterial Embedded Wearable Rectangular Microstrip Patch Antenna

Directory of Open Access Journals (Sweden)

J. G. Joshi

2012-01-01

Full Text Available This paper presents an indigenous low-cost metamaterial embedded wearable rectangular microstrip patch antenna using polyester substrate for IEEE 802.11a WLAN applications. The proposed antenna resonates at 5.10 GHz with a bandwidth and gain of 97 MHz and 4.92 dBi, respectively. The electrical size of this antenna is 0.254λ×0.5λ. The slots are cut in rectangular patch to reduce the bending effect. This leads to mismatch the impedance at WLAN frequency band; hence, a metamaterial square SRR is embedded inside the slot. A prototype antenna has been fabricated and tested, and the measured results are presented in this paper. The simulated and measured results of the proposed antenna are found to be in good agreement. The bending effect on the performance of this antenna is experimentally verified.

A Study on the RF-DC Conversion Efficiency of Microstrip Patch Rectenna

Energy Technology Data Exchange (ETDEWEB)

Jung, Yang Ha; Youn, Dong Gi; Kim, Kwan Ho [Korea Electrotechnology Research Institute (Korea); Rhee, Young Chul [Kyungnam University (Korea)

2000-07-01

We designed and manufactured microstrip patch antenna mainly used in the rectenna and then analysed RF-DC conversion efficiency of wireless power transmission system. We analyse conversion efficiency of load, direction of linear and dual polization rectenna. We found that the maximum efficiency would be about 70% of load and direction in patch type. In conclusion, we found that total conversion efficiency is 64% - 71% in patch Rectenna. (author). 5 refs., 8 figs., 1 tab.

Thermal Properties of the Silicon Microstrip Endcap Detector

CERN Document Server

Feld, Lutz; Hammarström, R

1998-01-01

Irradiated silicon detectors must be cooled in order to guarantee stable short and long term operation. Using the SiF1 milestone prototype we have performed a detailed analysis of the thermal properties of the silicon microstrip endcap detector. The strongest constraint on the cooling system is shown to be set by the need to avoid thermal runaway of the silicon detectors. We show that, taking into account the radiation damage to the silicon after 10 years of LHC operation and including some safety margin, the detector will need a cooling fluid temperature of around -20 C. The highest temperature on the silicon will then be in the range -15 C to -10 C. This sets an upper limit on the ambient temperature in the tracker volume.

Determination of electron beam polarization using electron detector in Compton polarimeter with less than 1% statistical and systematic uncertainty

Energy Technology Data Exchange (ETDEWEB)

Narayan, Amrendra [Mississippi State Univ., Mississippi State, MS (United States)

2015-05-01

The Q-weak experiment aims to measure the weak charge of proton with a precision of 4.2%. The proposed precision on weak charge required a 2.5% measurement of the parity violating asymmetry in elastic electron - proton scattering. Polarimetry was the largest experimental contribution to this uncertainty and a new Compton polarimeter was installed in Hall C at Jefferson Lab to make the goal achievable. In this polarimeter the electron beam collides with green laser light in a low gain Fabry-Perot Cavity; the scattered electrons are detected in 4 planes of a novel diamond micro strip detector while the back scattered photons are detected in lead tungstate crystals. This diamond micro-strip detector is the first such device to be used as a tracking detector in a nuclear and particle physics experiment. The diamond detectors are read out using custom built electronic modules that include a preamplifier, a pulse shaping amplifier and a discriminator for each detector micro-strip. We use field programmable gate array based general purpose logic modules for event selection and histogramming. Extensive Monte Carlo simulations and data acquisition simulations were performed to estimate the systematic uncertainties. Additionally, the Moller and Compton polarimeters were cross calibrated at low electron beam currents using a series of interleaved measurements. In this dissertation, we describe all the subsystems of the Compton polarimeter with emphasis on the electron detector. We focus on the FPGA based data acquisition system built by the author and the data analysis methods implemented by the author. The simulations of the data acquisition and the polarimeter that helped rigorously establish the systematic uncertainties of the polarimeter are also elaborated, resulting in the first sub 1% measurement of low energy (?1 GeV) electron beam polarization with a Compton electron detector. We have demonstrated that diamond based micro-strip detectors can be used for tracking in a

Automated testing of microstrip detectors readout system for dual x-ray dual energy

International Nuclear Information System (INIS)

Bolanos, L.; Cabal, A. E.; Diaz, A.; Swientek, K.; Giubellino, P.; Marzari-Chiesa, A.; Prino, F.; Ramello, L.

2008-01-01

Circuits that carry out the signal acquisition and processing by multiple channels are required in digital radiography. These circuits should be tested in order to characterize their performance. This paper describes an automated system to control (by a software, from a personal computer) the characterization of a system based on RX64DTH specific integrated circuits with microstrip detectors. The results are shown. (Author)

Flexible microstrip antenna based on carbon nanotubes/(ethylene-octene copolymer) thin composite layer deposited on PET substrate

Science.gov (United States)

Matyas, J.; Olejnik, R.; Slobodian, P.

2017-12-01

A most of portable devices, such as mobile phones, tablets, uses antennas made of cupper. In this paper we demonstrate possible use of electrically conductive polymer composite material for such antenna application. Here we describe the method of preparation and properties of the carbon nanotubes (CNTs)/(ethylene-octene copolymer) as flexible microstrip antenna. Carbon nanotubes dispersion in (ethylene-octene copolymer) toluene solution was prepared by ultrasound finally coating PET substrate by method of dip-coating. Main advantages of PET substrate are low weight and also flexibility. The final size of flexible microstrip antenna was 5 x 50 mm with thickness of 0.48 mm (PET substrate 0.25 mm) with the weight of only 0.402 g. Antenna operates at three frequencies 1.66 GHz (-6.51 dB), 2.3 GHz (-13 dB) and 2.98 GHz (-33.59 dB).

Finite element modeling of piezoelectric elements with complex electrode configuration

International Nuclear Information System (INIS)

Paradies, R; Schläpfer, B

2009-01-01

It is well known that the material properties of piezoelectric materials strongly depend on the state of polarization of the individual element. While an unpolarized material exhibits mechanically isotropic material properties in the absence of global piezoelectric capabilities, the piezoelectric material properties become transversally isotropic with respect to the polarization direction after polarization. Therefore, for evaluating piezoelectric elements the material properties, including the coupling between the mechanical and the electromechanical behavior, should be addressed correctly. This is of special importance for the micromechanical description of piezoelectric elements with interdigitated electrodes (IDEs). The best known representatives of this group are active fiber composites (AFCs), macro fiber composites (MFCs) and the radial field diaphragm (RFD), respectively. While the material properties are available for a piezoelectric wafer with a homogeneous polarization perpendicular to its plane as postulated in the so-called uniform field model (UFM), the same information is missing for piezoelectric elements with more complex electrode configurations like the above-mentioned ones with IDEs. This is due to the inhomogeneous field distribution which does not automatically allow for the correct assignment of the material, i.e. orientation and property. A variation of the material orientation as well as the material properties can be accomplished by including the polarization process of the piezoelectric transducer in the finite element (FE) simulation prior to the actual load case to be investigated. A corresponding procedure is presented which automatically assigns the piezoelectric material properties, e.g. elasticity matrix, permittivity, and charge vector, for finite element models (FEMs) describing piezoelectric transducers according to the electric field distribution (field orientation and strength) in the structure. A corresponding code has been

Prototype Si microstrip sensors for the CDF-II ISL detector

CERN Document Server

Hara, K; Kanao, K; Kim, S; Ogasawara, M; Ohsugi, T; Shimojima, M; Takikawa, K

1999-01-01

Prototype Si microstrip sensors for the CDF-II ISL were fabricated by Hamamatsu Photonics and SEIKO Instruments using 4'' technology. The sensor is AC coupled and double-sided forming a stereo angle of 1.207 degree sign . The strip pitch is 112 mu m on both sides. The main differences between the two manufacturers lie on the technologies of passivation and the structure of coupling capacitors. We describe the design of the sensor and evaluation results of the performance. The evaluations include the total and individual strip currents and interstrip capacitance measured before and after sup 6 sup 0 Co gamma irradiation. (author)

Reduction of coating induced polarization aberrations by controlling the polarization state variation

International Nuclear Information System (INIS)

Li, Yanghui; Shen, Weidong; Zheng, Zhenrong; Zhang, Yueguang; Liu, Xu; Hao, Xiang

2011-01-01

The mechanism of coating induced polarization state variation is analysed by the Jones matrix. Pauli spin matrices are used to establish the relationship between coating induced polarization state variation and polarization aberrations. To reduce coating induced polarization aberrations, we propose that δ = 0 and T s = T p at arbitrary incident angle should be appended as two additional optimization goals of optical coating design when the requirements of transmittance are met. Two typical anti-reflection (AR) coatings are designed and the polarization state variation induced by them is simulated. The MTF (modulation transfer function) calculated by polarization ray tracing is applied to evaluate the polarization aberrations of the practical lithography objective system with the two AR coatings. All the obtained results show that the coating induced polarization aberrations can be reduced by optimizing the angle dependent properties of the optical coating without additional optical elements

Dual Band Parasitic Element Patch Antenna for LTE/WLAN Applications

Directory of Open Access Journals (Sweden)

BAG Biplab

2017-05-01

Full Text Available In this paper, a single layer coaxial fed dual band slotted microstrip antenna is proposed. The proposed antenna consists of two direct couple parasitic elements and L-shape slots on the main resonating element. Two resonant modes are excited and it covers 4G LTE and WLAN middle band. The -10dB impedance bandwidth for resonant frequency of 2.35GHz and 5.28GHz are 140MHz (2.25-2.39GHz and 570MHz (5.18-5.75GHz, respectively. The measured VSWR at 2.35GHz is 1.27 and at 5.28GHz is 1.41. The proposed antenna is simple in design and compact in size. The simulated and measured results are in good agreement.

A new design of a miniature filter on microstrip resonators with an interdigital structure of conductors

Science.gov (United States)

Belyaev, B. A.; Serzhantov, A. M.; Bal'va, Ya. F.; Leksikov, An. A.; Galeev, R. G.

2015-05-01

A microstrip bandpass filter of new design based on original resonators with an interdigital structure of conductors has been studied. The proposed filters of third to sixth order are distinguished for their high frequency-selective properties and much smaller size than analogs. It is established that a broad stop band, extending up to a sixfold central bandpass frequency, is determined by low unloaded Q of higher resonance mode and weak coupling of resonators in the pass band. It is shown for the first time that, as the spacing of interdigital stripe conductors decreases, the Q of higher resonance mode monotonically drops, while the Q value for the first operating mode remains high. A prototype fourth-order filter with a central frequency of 0.9 GHz manufactured on a ceramic substrate with dielectric permittivity ɛ = 80 has microstrip topology dimensions of 9.5 × 4.6 × 1 mm3. The electrodynamic 3D model simulations of the filter characteristics agree well with the results of measurements.

The silicon microstrip sensors of the ATLAS semiconductor tracker

Energy Technology Data Exchange (ETDEWEB)

ATLAS SCT Collaboration; Spieler, Helmuth G.

2007-04-13

This paper describes the AC-coupled, single-sided, p-in-n silicon microstrip sensors used in the Semiconductor Tracker (SCT) of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The sensor requirements, specifications and designs are discussed, together with the qualification and quality assurance procedures adopted for their production. The measured sensor performance is presented, both initially and after irradiation to the fluence anticipated after 10 years of LHC operation. The sensors are now successfully assembled within the detecting modules of the SCT, and the SCT tracker is completed and integrated within the ATLAS Inner Detector. Hamamatsu Photonics Ltd. supplied 92.2percent of the 15,392 installed sensors, with the remainder supplied by CiS.

Development of Microstrip Silicon Detectors for Star and ALICE

CERN Document Server

Arnold, L; Coffin, J P; Guillaume, G; Guthneck, L; Higueret, S; Hundt, F; Kühn, C E; Lutz, Jean Robert; Pozdniakov, S; Rami, F; Tarchini, A; Boucham, A; Bouvier, S; Erazmus, B; Germain, M; Giliberto, S; Martin, L; Le Moal, C; Roy, C; Colledani, C; Dulinski, W; Turchetta, R

1998-01-01

The physics program of STAR and ALICE at ultra-relativistic heavy ion colliders, RHIC and LHC respectively, requires very good tracking capabilities. Some specific quark gluon plasma signatures, based on strange matter measurements implies quite a good secondary vertex reconstruction.For this purpose, the inner trackers of both experiments are composed of high-granularity silicon detectors. The current status of the development of double-sided silicon microstrip detectors is presented in this work.The global performance for tracking purpose adn particle identification are first reviewed. Then tests of the detectors and of the associated readout electronics are described. In-beam measurements of noise, spatial resolution, efficiency and charge matching capability, as well as radiation hardness, are examined.

The silicon microstrip sensors of the ATLAS semiconductor tracker

International Nuclear Information System (INIS)

ATLAS SCT Collaboration; Spieler, Helmuth G.

2007-01-01

This paper describes the AC-coupled, single-sided, p-in-n silicon microstrip sensors used in the Semiconductor Tracker (SCT) of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The sensor requirements, specifications and designs are discussed, together with the qualification and quality assurance procedures adopted for their production. The measured sensor performance is presented, both initially and after irradiation to the fluence anticipated after 10 years of LHC operation. The sensors are now successfully assembled within the detecting modules of the SCT, and the SCT tracker is completed and integrated within the ATLAS Inner Detector. Hamamatsu Photonics Ltd. supplied 92.2percent of the 15,392 installed sensors, with the remainder supplied by CiS

Spiral Slotted Microstrip Antenna Design for 700 MHz Band Application

Directory of Open Access Journals (Sweden)

Ricardo Meneses González

2016-01-01

Full Text Available This work describes the design and implementation of spiral slotted microstrip antenna. Recently, just like other countries, in Mexico, terrestrial digital television has been implemented (analogic shutdown; as a consequence, the 700 MHz UFH Band (698–806 MHz has been opened to new telecommunications services, particularly wireless mobile communication. This technological advance represents a radio mobile antenna design challenge because it is necessary to design an antenna whose dimensions must be small enough, which satisfies gain, resonance frequency, and bandwidth requirements and is of low cost.

Performance of a beam telescope using double sided silicon microstrip detectors

International Nuclear Information System (INIS)

Fischer, P.; Menke, S.; Wermes, N.

1995-04-01

A beam telescope consisting of four double sided, DC coupled microstrip detectors with VLSI readout electronics has been built and tested in a 70 GeV μ - beam at CERN. A signal to noise ratio of 53:1 and a spatial resolution of 2.7 μm (junction side) and 4.8 μm (ohmic side) have been observed on the best detectors. A telescope performance for a particle track of σ xy =2-3 μm and σ slope =2-3 μrad on the front face of a test object was achieved. (orig.)

Non-invasive characterization and quality assurance of silicon micro-strip detectors using pulsed infrared laser

Science.gov (United States)

Ghosh, P.

2016-01-01

The Compressed Baryonic Matter (CBM) experiment at FAIR is composed of 8 tracking stations consisting of roughly 1300 double sided silicon micro-strip detectors of 3 different dimensions. For the quality assurance of prototype micro-strip detectors a non-invasive detector charaterization is developed. The test system is using a pulsed infrared laser for charge injection and characterization, called Laser Test System (LTS). The system is aimed to develop a set of characterization procedures which are non-invasive (non-destructive) in nature and could be used for quality assurances of several silicon micro-strip detectors in an efficient, reliable and reproducible way. The procedures developed (as reported here) uses the LTS to scan sensors with a pulsed infra-red laser driven by step motor to determine the charge sharing in-between strips and to measure qualitative uniformity of the sensor response over the whole active area. The prototype detector modules which are tested with the LTS so far have 1024 strips with a pitch of 58 μm on each side. They are read-out using a self-triggering prototype read-out electronic ASIC called n-XYTER. The LTS is designed to measure sensor response in an automatized procedure at several thousand positions across the sensor with focused infra-red laser light (spot size ≈ 12 μm, wavelength = 1060 nm). The pulse with a duration of ≈ 10 ns and power ≈ 5 mW of the laser pulse is selected such, that the absorption of the laser light in the 300 μm thick silicon sensor produces ≈ 24000 electrons, which is similar to the charge created by minimum ionizing particles (MIP) in these sensors. The laser scans different prototype sensors and various non-invasive techniques to determine characteristics of the detector modules for the quality assurance is reported.

CIRCULARLY POLARIZED SLOTTED APERTURE ANTENNA WITH COPLANAR WAVEGUIDE FED FOR BROADBAND APPLICATIONS

Directory of Open Access Journals (Sweden)

B. T. P. MADHAV

2016-02-01

Full Text Available Coplanar waveguide fed circularly polarized microstrip patch antenna performance evaluation is presented in this paper. The broadband characteristics are attained by placing open end slot at the lower side of the antenna. The proposed design has the return loss of less than -10dB and VSWR<2 in the desired band of operation. A gain of 3dB to 4dB is attained in the desired band with good radiation characteristics and a suitable axial ratio of less than 3 dB is attained in the prescribed band of operation. Proposed antenna is fabricated on the FR4 substrate with dielectric constant of 4.4. Parametric analysis with change in substrate permittivity also performed and the optimized dimensions are presented in this work.

An X-ray imager based on silicon microstrip detector and coded mask

International Nuclear Information System (INIS)

Del Monte, E.; Costa, E.; Di Persio, G.; Donnarumma, I.; Evangelista, Y.; Feroci, M.; Frutti, M.; Lapshov, I.; Lazzarotto, F.; Mastropietro, M.; Morelli, E.; Pacciani, L.; Porrovecchio, G.; Rapisarda, M.; Rubini, A.; Soffitta, P.; Tavani, M.; Argan, A.

2007-01-01

SuperAGILE is the X-ray monitor of AGILE, a satellite mission for gamma-ray astronomy, and it is the first X-ray imaging instrument based on the technology of the silicon microstrip detectors combined with a coded aperture imaging technique. The SuperAGILE detection plane is composed of four 1-D silicon microstrip detector modules, mechanically coupled to tungsten coded mask units. The detector strips are separately and individually connected to the input analogue channels of the front-end electronics, composed of low-noise and low-power consumption VLSI ASIC chips. SuperAGILE can produce 1-D images with 6 arcmin angular resolution and ∼2-3 arcmin localisation capability, for intense sources, in a field of view composed of two orthogonal areas of 107 deg. x 68 deg. The time resolution is 2 μs, the overall dead time is ∼5 μs and the electronic noise is ∼7.5 keV full-width at half-maximum. The resulting instrument is very compact (40x40x14 cm 3 ), light (10 kg) and has low power consumption (12 W). AGILE is a mission of the Agenzia Spaziale Italiana and its launch is planned in 2007 in a low equatorial Earth orbit. In this contribution we present SuperAGILE and discuss its performance and scientific objectives

Silicon microstrip detectors on 6'' technology

CERN Document Server

Bölla, G; Günther, M; Martignon, G; Bacchetta, N; Bisello, D; Leonardi, G L; Lucas, T; Wilburn, C

1999-01-01

The fabrication of microstrip detectors on 4'' high-resistivity wafers that allow for a maximum workable area of about 42 cm sup 2 has been well established. Using 6'' wafers the workable area increases up to 100 cm sup 2 (more than twice the area of a 4'' wafer) allowing a larger number of detectors to be processed at the same time on the same wafer resulting in a sizable reduction of cost. After a prototyping stage, the CDF silicon tracker upgrade is now receiving final production sensors from Micron Semiconductor Ltd. The performance of double-sided single-metal small stereo angle sensors for the CDF SVXII and ISL detectors has been studied. Results include probe station measurements and test beam results. The problems encountered from prototyping to the final devices are described. A brief overview of the response of the sensors to irradiation with gamma-rays and p sup + up to a dose of 0.5 Mrad (well above the doses expected during Run II of the Tevatron) is included. (author)

Method and apparatus for magnetic resonance imaging and spectroscopy using microstrip transmission line coils

Science.gov (United States)

Zhang, Xiaoliang; Ugurbil, Kamil; Chen, Wei

2006-04-04

Apparatus and method for MRI imaging using a coil constructed of microstrip transmission line (MTL coil) are disclosed. In one method, a target is positioned to be imaged within the field of a main magnetic field of a magnet resonance imaging (MRI) system, a MTL coil is positioned proximate the target, and a MRI image is obtained using the main magnet and the MTL coil. In another embodiment, the MRI coil is used for spectroscopy. MRI imaging and spectroscopy coils are formed using microstrip transmission line. These MTL coils have the advantageous property of good performance while occupying a relatively small space, thus allowing MTL coils to be used inside restricted areas more easily than some other prior art coils. In addition, the MTL coils are relatively simple to construct of inexpensive components and thus relatively inexpensive compared to other designs. Further, the MTL coils of the present invention can be readily formed in a wide variety of coil configurations, and used in a wide variety of ways. Further, while the MTL coils of the present invention work well at high field strengths and frequencies, they also work at low frequencies and in low field strengths as well.

Investigation of New Microstrip Bandpass Filter Based on Patch Resonator with Geometrical Fractal Slot.

Directory of Open Access Journals (Sweden)

Yaqeen S Mezaal

Full Text Available A compact dual-mode microstrip bandpass filter using geometrical slot is presented in this paper. The adopted geometrical slot is based on first iteration of Cantor square fractal curve. This filter has the benefits of possessing narrower and sharper frequency responses as compared to microstrip filters that use single mode resonators and traditional dual-mode square patch resonators. The filter has been modeled and demonstrated by Microwave Office EM simulator designed at a resonant frequency of 2 GHz using a substrate of εr = 10.8 and thickness of h = 1.27 mm. The output simulated results of the proposed filter exhibit 22 dB return loss, 0.1678 dB insertion loss and 12 MHz bandwidth in the passband region. In addition to the narrow band gained, miniaturization properties as well as weakened spurious frequency responses and blocked second harmonic frequency in out of band regions have been acquired. Filter parameters including insertion loss, return loss, bandwidth, coupling coefficient and external quality factor have been compared with different values of perturbation dimension (d. Also, a full comparative study of this filter as compared with traditional square patch filter has been considered.

Off-diagonal helicity density matrix elements for vector mesons produced in polarized e+e- processes

International Nuclear Information System (INIS)

Anselmino, M.; Murgia, F.; Quintairos, P.

1999-04-01

Final state q q-bar interactions give origin to non zero values of the off-diagonal element ρ 1,-1 of the helicity density matrix of vector mesons produced in e + e - annihilations, as confirmed by recent OPAL data on φ, D * and K * 's. New predictions are given for ρ 1,-1 of several mesons produced at large x E and small p T - i.e. collinear with the parent jet - in the annihilation of polarized 3 + and 3 - , the results depend strongly on the elementary dynamics and allow further non trivial tests of the standard model. (author)

Radiation tolerance of the FOXFET biasing scheme for AC-coupled Si microstrip detectors

International Nuclear Information System (INIS)

Bacchetta, N.; Gotra, Yu.; Bisello, D.; Da Ros, R.; Giraldo, A.; Fusaro, G.; Paccagnella, A.; Univ. di Cagliari; Verzellesi, G.; Univ. di Padova

1993-01-01

The radiation response of FOXFETs has been studied for proton, gamma and neutron exposures. The punch-through behavior, which represents the normal FET operating conditions in Si microstrip detectors, has been found to be much less sensitive to radiation damage than threshold voltage. The device performance has been elucidated by means of two-dimensional simulations. The main radiation effects have been also taken into account in the numerical analysis and separately examined

Design, fabrication and characterization of the first AC-coupled silicon microstrip sensors in India

International Nuclear Information System (INIS)

Aziz, T; Chendvankar, S R; Mohanty, G B; Patil, M R; Rao, K K; Rani, Y R; Rao, Y P P; Behnamian, H; Mersi, S; Naseri, M

2014-01-01

This paper reports the design, fabrication and characterization of single-sided silicon microstrip sensors with integrated biasing resistors and coupling capacitors, produced for the first time in India. We have first developed a prototype sensor on a four-inch wafer. After finding suitable test procedures for characterizing these AC coupled sensors, we fine-tuned various process parameters in order to produce sensors of the desired specifications

Micro-discharge noise and radiation damage of silicon microstrip sensors

International Nuclear Information System (INIS)

Ohsugi, T.; Iwata, Y.; Ohyama, H.; Ohmoto, T.; Yoshikawa, M.; Handa, T.; Kurino, K.; Fujita, K.; Kitabayashi, H.; Tamura, N.; Hatakenaka, T.; Maeohmichi, M.; Takahata, M.; Nakao, M.; Iwasaki, H.; Kohriki, T.; Terada, S.; Unno, Y.; Takashima, R.; Yamamoto, K.; Yamamura, K.

1996-01-01

We have examined experimentally some existing ideas for improving the radiation hardness of silicon microstrip sensors. We confirm that the extended electrode and the deep implant-strip proposed on the basis of simulation studies works effectively to suppress micro-discharge as well as junction breakdown of the bias or guard ring. For an integrated coupling capacitor a double layer structure of SiO 2 and Si 3 N 4 provides better radiation hardness than that of single SiO 2 coupling in our design conditions. The onset voltage of the micro-discharge on the bias/guard ring has been studied for an extended electrode and a floating guard ring. (orig.)

A Design Of Feeding Network For A Dual-Linear Polarization, Stacked, Probe-Fed Microstrip Patch Antenna Array

DEFF Research Database (Denmark)

Jaworski, G.; Krozer, Viktor

2004-01-01

Components of multilayer feed network are presented for application in broad-band dual-linear polarized stacked C-band antenna. Measurement results of wide band matching circuits and different types of power divider networks constituting parts of BFN demonstrate wideband operation. Suitable...

Operation of high rate microstrip gas chambers

CERN Document Server

Barr, A J; Bouclier, Roger; Capéans-Garrido, M; Dominik, Wojciech; Manzin, G; Million, Gilbert; Hoch, M; Ropelewski, Leszek; Sauli, Fabio; Sharma, A

1996-01-01

We describe recent measurements carried out in well controlled and reproducible conditions to help understanding the factors affecting the short and long term behaviour of Microstrip Gas Chambers. Special care has been taken concerning the gas purity and choice of materials used in the system and for the detectors construction. Detectors built on glasses with surface resistivity in the range $10^{13}-10^{15} \\Omega/\\Box$ have shown satisfactory performance as they do not show charging-up process at high rate and stand the large doses required for the future high luminosity experiments (~10 mC·cm-1·yr-1). Concerning the lifetime measurements, it has been observed that chambers manufactured on high-resistivity glass are far more susceptible of suffering ageing than detectors made on low resistivity, electron-conducting supports, independently of the metal used for the artwork (chromium or gold) at least in clean gas conditions. The successfully operation in the laboratory of detectors manufactured on diamond-...

Novel micromachined on-chip 10-elements wire-grid array operating at 60 GHz

KAUST Repository

Sallam, Mai O.

2017-06-07

This paper presents a new topology for a wire-grid antenna array which operates at 60 GHz. The array consists of ten λ/2 dipole radiators connected via non-radiating connectors. Both radiators and connectors are placed on top of narrow silicon walls. The antenna is fed with a coplanar microstrip lines placed at the other side of the wafer and is connected with its feeding transmission lines using through-silicon-vias. The antenna is optimized for two cases: using high- and low-resistivity silicon substrates. The former has better radiation characteristics while the later is more compatible with the driving electronic circuits. The antenna has high directivity, reasonable bandwidth and high polarization purity.

Optimising the design of gas microstrip detectors for soft x-ray detection

International Nuclear Information System (INIS)

Bateman, J.; Barlow, R.; Derbyshire, G.

2001-01-01

This report describes development work in which systematic changes in the electrode pattern of a Gas Microstrip Detector are explored in the search for higher avalanche gains and enhanced stability. It is found that the width of the cathode structure is the main determinant of the detector stability. With the correct cathode width, gas gains of >50 000 are comfortably attainable with low detector noise so that x-rays can potentially be detected down to the limit of a single x-ray-produced photoelectron. (author)

Microstrip Cross-coupled Interdigital SIR Based Bandpass Filter

Directory of Open Access Journals (Sweden)

R. K. Maharjan

2012-09-01

Full Text Available A simple and compact 4.9 GHz bandpass filter for C-band applications is proposed. This paper presents a novel microstrip cross-coupled interdigital half-wavelength stepped impedance resonator (SIR based bandpass filter (BPF.The designed structure is similar to that of a combination of two parallel interdigital capacitors. The scattering parameters of the structure are measured using vector network analyzer (VNA. The self generated capacitive and inductive reactances within the interdigital resonators exhibited in a resonance frequency of 4.9 GHz. The resonant frequency and bandwidth of the capacitive cross-coupled resonator is directly optimized from the physical arrangement of the resonators. The measured insertion loss (S21 and return loss (S11 were 0.3 dB and 28 dB, respectively, at resonance frequency which were almost close to the simulation results.

Design of a Front– End Amplifier for the Maximum Power Delivery and Required Noise by HBMO with Support Vector Microstrip Model

Directory of Open Access Journals (Sweden)

F. Guneş

2014-04-01

Full Text Available Honey Bee Mating Optimization (HBMO is a recent swarm-based optimization algorithm to solve highly nonlinear problems, whose based approach combines the powers of simulated annealing, genetic algorithms, and an effective local search heuristic to search for the best possible solution to the problem under investigation within a reasonable computing time. In this work, the HBMO- based design is carried out for a front-end amplifier subject to be a subunit of a radar system in conjunction with a cost effective 3-D SONNET-based Support Vector Regression Machine (SVRM microstrip model. All the matching microstrip widths, lengths are obtained on a chosen substrate to satisfy the maximum power delivery and the required noise over the required bandwidth of a selected transistor. The proposed HBMO- based design is applied to the design of a typical ultra-wide-band low noise amplifier with NE3512S02 on a substrate of Rogers 4350 for the maximum output power and the noise figure F(f=1dB within the 5-12 GHz using the T- type of microstrip matching circuits. Furthermore, the effectiveness and efficiency of the proposed HBMO based design are manifested by comparing it with the Genetic Algorithm (GA, Particle Swarm Optimization (PSO and the simple HBMO based designs.

Test beam results of a low-pressure micro-strip gas chamber with a secondary-electron emitter

International Nuclear Information System (INIS)

Kwan, S.; Anderson, D.F.; Zimmerman, J.; Sbarra, C.; Salomon, M.

1994-10-01

We present recent results, from a beam test, on the angular dependence of the efficiency and the distribution of the signals on the anode strips of a low-pressure microstrip gas chamber with a thick CsI layer as a secondary-electron emitter. New results of CVD diamond films as secondary-electron emitters are discussed

Partial Polarization in Interfered Plasmon Fields

Directory of Open Access Journals (Sweden)

P. Martínez Vara

2014-01-01

Full Text Available We describe the polarization features for plasmon fields generated by the interference between two elemental surface plasmon modes, obtaining a set of Stokes parameters which allows establishing a parallelism with the traditional polarization model. With the analysis presented, we find the corresponding coherence matrix for plasmon fields incorporating to the plasmon optics the study of partial polarization effects.

Signal generation in highly irradiated silicon microstrip detectors for the ATLAS experiment

International Nuclear Information System (INIS)

Ruggiero, Gennaro

2003-01-01

Silicon detectors are the most diffused tracking devices in High Energy Physics (HEP). The reason of such success can be found in the characteristics of the material together with the existing advanced technology for the fabrication of these devices. Nevertheless in many modem HEP experiments the observation of vary rare events require data taking at high luminosity with a consequent extremely intense hadron radiation field that damages the silicon and degrades the performance of these devices. In this thesis work a detailed study of the signal generation in microstrip detectors has been produced with a special care for the ATLAS semiconductor tracker geometry. This has required a development of an appropriate setup to perform measurements with Transient Current/ Charge Technique. This has allowed studying the evolution of the signal in several microstrips detector samples irradiated at fluences covering the range expected in the ATLAS Semiconductor Tracker. For a better understanding of these measurements a powerful software package that simulates the signal generation in these devices has been developed. Moreover in this thesis it has been also shown that the degradation due to radiation in silicon detectors can be strongly reduced if the data taking is done with detectors operated at 130 K. This makes low temperature operation that benefits of the recovery of the charge collection efficiency in highly irradiated silicon detectors (also known as Lazarus effect) an optimal option for future high luminosity experiments. (author)

Multi-Channel Capacitive Sensor Arrays

Directory of Open Access Journals (Sweden)

Bingnan Wang

2016-01-01

Full Text Available In this paper, multi-channel capacitive sensor arrays based on microstrip band-stop filters are studied. The sensor arrays can be used to detect the proximity of objects at different positions and directions. Each capacitive sensing structure in the array is connected to an inductive element to form resonance at different frequencies. The resonances are designed to be isolated in the frequency spectrum, such that the change in one channel does not affect resonances at other channels. The inductive element associated with each capacitive sensor can be surface-mounted inductors, integrated microstrip inductors or metamaterial-inspired structures. We show that by using metamaterial split-ring structures coupled to a microstrip line, the quality factor of each resonance can be greatly improved compared to conventional surface-mounted or microstrip meander inductors. With such a microstrip-coupled split-ring design, more sensing elements can be integrated in the same frequency spectrum, and the sensitivity can be greatly improved.

Decay of correlations between cross-polarized electromagnetic waves in a two-dimensional random medium.

Science.gov (United States)

Gorodnichev, E E

2018-04-01

The problem of multiple scattering of polarized light in a two-dimensional medium composed of fiberlike inhomogeneities is studied. The attenuation lengths for the density matrix elements are calculated. For a highly absorbing medium it is found that, as the sample thickness increases, the intensity of waves polarized along the fibers decays faster than the other density matrix elements. With further increase in the sample thickness, the off-diagonal elements which are responsible for correlations between the cross-polarized waves disappear. In the asymptotic limit of very thick samples the scattered light proves to be polarized perpendicular to the fibers. The difference in the attenuation lengths between the density matrix elements results in a nonmonotonic depth dependence of the degree of polarization. In the opposite case of a weakly absorbing medium, the off-diagonal element of the density matrix and, correspondingly, the correlations between the cross-polarized fields are shown to decay faster than the intensity of waves polarized along and perpendicular to the fibers.

Design and fabrication of a microstrip patch antenna with a low radar cross section in the X-band

International Nuclear Information System (INIS)

Jang, Hong-Kyu; Lee, Won-Jun; Kim, Chun-Gon

2011-01-01

In this study, the authors developed a radar absorbing method to reduce the antenna radar cross section (RCS) without any loss of antenna performance. The new method was based upon an electromagnetic bandgap (EBG) absorber using conducting polymer (CP). First, a microstrip patch antenna was made by using a copper film and glass/epoxy composite materials, which are typically used for load-bearing structures, such as aircraft and other vehicles. Then, CP EBG patterns were also designed that had a 90% electromagnetic (EM) wave absorbing performance within the X-band (8.2–12.4 GHz). Finally, the CP EBG patterns were printed on the top surface of the microstrip patch antenna. The measured radar absorbing performance of the fabricated patch antenna showed that the frontal RCS of the antenna declined by nearly 95% at 10 GHz frequency while the CP EBG patterns had almost no effect on the antenna's performance

Performance of a single photon counting microstrip detector for strip pitches down to 10 μm

International Nuclear Information System (INIS)

Bergamaschi, A.; Broennimann, Ch.; Dinapoli, R.; Eikenberry, E.; Gozzo, F.; Henrich, B.; Kobas, M.; Kraft, P.; Patterson, B.; Schmitt, B.

2008-01-01

The MYTHEN detector is a one-dimensional microstrip detector with single photon counting readout optimized for time resolved powder diffraction experiments at the Swiss Light Source (SLS). The system has been successfully tested for many different synchrotron radiation applications including phase contrast and tomographic imaging, small angle scattering, diffraction and time resolved pump and probe experiments for X-ray energies down to 5 keV and counting rate up to 3 MHz. The frontend electronics is designed in order to be coupled to 50 μm pitch microstrip sensors but some interest in enhancing the spatial resolution is arising for imaging and powder diffraction experiments. A test structure with strip pitches in the range 10-50 μm has been tested and the gain and noise on the readout electronics have been measured for the different strip pitches, observing no large difference down to 25 μm. Moreover, the effect of the charge sharing between neighboring strips on the spatial resolution has been quantified by measuring the Point Spread Function (PSF) of the system for the different pitches

Performance of a single photon counting microstrip detector for strip pitches down to 10 μm

Science.gov (United States)

Bergamaschi, A.; Broennimann, Ch.; Dinapoli, R.; Eikenberry, E.; Gozzo, F.; Henrich, B.; Kobas, M.; Kraft, P.; Patterson, B.; Schmitt, B.

2008-06-01

The MYTHEN detector is a one-dimensional microstrip detector with single photon counting readout optimized for time resolved powder diffraction experiments at the Swiss Light Source (SLS). The system has been successfully tested for many different synchrotron radiation applications including phase contrast and tomographic imaging, small angle scattering, diffraction and time resolved pump and probe experiments for X-ray energies down to 5 keV and counting rate up to 3 MHz. The frontend electronics is designed in order to be coupled to 50 μm pitch microstrip sensors but some interest in enhancing the spatial resolution is arising for imaging and powder diffraction experiments. A test structure with strip pitches in the range 10-50 μm has been tested and the gain and noise on the readout electronics have been measured for the different strip pitches, observing no large difference down to 25 μm. Moreover, the effect of the charge sharing between neighboring strips on the spatial resolution has been quantified by measuring the Point Spread Function (PSF) of the system for the different pitches.

Observing the Cosmic Microwave Background Polarization with Variable-delay Polarization Modulators for the Cosmology Large Angular Scale Surveyor

Science.gov (United States)

Harrington, Kathleen; CLASS Collaboration

2018-01-01

The search for inflationary primordial gravitational waves and the optical depth to reionization, both through their imprint on the large angular scale correlations in the polarization of the cosmic microwave background (CMB), has created the need for high sensitivity measurements of polarization across large fractions of the sky at millimeter wavelengths. These measurements are subjected to instrumental and atmospheric 1/f noise, which has motivated the development of polarization modulators to facilitate the rejection of these large systematic effects.Variable-delay polarization modulators (VPMs) are used in the Cosmology Large Angular Scale Surveyor (CLASS) telescopes as the first element in the optical chain to rapidly modulate the incoming polarization. VPMs consist of a linearly polarizing wire grid in front of a moveable flat mirror; varying the distance between the grid and the mirror produces a changing phase shift between polarization states parallel and perpendicular to the grid which modulates Stokes U (linear polarization at 45°) and Stokes V (circular polarization). The reflective and scalable nature of the VPM enables its placement as the first optical element in a reflecting telescope. This simultaneously allows a lock-in style polarization measurement and the separation of sky polarization from any instrumental polarization farther along in the optical chain.The Q-Band CLASS VPM was the first VPM to begin observing the CMB full time in 2016. I will be presenting its design and characterization as well as demonstrating how modulating polarization significantly rejects atmospheric and instrumental long time scale noise.

PENGEMBANGAN VARIATIF RANCANGAN ANTENA PANEL MICROSTRIP TAPERED PATCH DALAM SISTEM KOMUNIKASI WI-FI

Directory of Open Access Journals (Sweden)

Putu Artawan

2013-04-01

Full Text Available Pada penelitian ini dilakukan pengembangan rancangan antena microstrip tapered patch untuk dilakukan pengukuran parameternya sebagai karakteristik dari antena Microstrip. Penelitian ini sebagai pengembangan variatif rancangan untuk memperoleh hasil yang lebih optimal. Metode eksperiment dilakukan dalam penelitian ini. Tahap pengerjaanya yaitu membuat desain rancangan antena sesuai persamaan yang ada yang kemudian dirancang dengan metode UV Photoresist laminate. Hasil rancangan antena diukur untuk mendapatkan karakteristik sebagai parameter antena meliputi frekuensi (bandwidth, SWR, VSWR, koofesien refleksi, pola radiasi dan penguatan (gain serta nilai HPBW. Nilai-nilai tersebut mencerminkan karakter dari sebuah antena sebagai parameter antena yang layak diimplementasikan dalam sistem komunikasi internet dengan sistem wi-fi. Hasil penelitian ini meliputi: nilai lebar pita (bandwidth = 0.21 GHz, VSWR = 1,23, SWR = 1,79,  return loss = -20,00 dB, koofesien refleksi = 0,10 dan grafik pola radiasi dengan penguatan (gain = 17 dB (polarisasi vertikal, 20 dB (polarisasi horizontal. Nilai Half Power Beamwidth (HPBW 820 untuk pola radiasi vertikal dan pola radiasi horizontal. Kesalahan (error hasil pengukuran 0,12% dengan keseksamaan 99,88%. Hasil ini memberikan indikasi sebagai rancangan antena yang layak untuk sistem komunikasi wi-fi. Penelitian ini sebagai salah satu aplikasi ilmu Fisika dalam dunia teknologi informasi dan diharapkan dapat bermanfaat sebagai dinamika wahana salah satu produk penerapan ilmu Fisika dalam bidang Teknologi Informasi.

Electrical production testing of the D0 Silicon microstrip tracker detector modules

Energy Technology Data Exchange (ETDEWEB)

D0, SMT Production Testing Group; /Fermilab

2006-03-01

The D0 Silicon Microstrip Tracker (SMT) is the innermost system of the D0 detector in Run 2. It consists of 912 detector units, corresponding to 5 different types of assemblies, which add up to a system with 792,576 readout channels. The task entrusted to the Production Testing group was to thoroughly debug, test and grade each detector module before its installation in the tracker. This note describes the production testing sequence and the procedures by which the detector modules were electrically tested and characterized at the various stages of their assembly.

Design optimization of a breast imaging system based on silicon microstrip detectors

International Nuclear Information System (INIS)

Stres, S.; Mikuz, M.

2000-01-01

A mammographic imaging set-up using silicon microstrip detectors in edge-on geometry was simulated using the GEANT package. Deposited energy in tissue of various thicknesses was evaluated and shown to agree to within 10% with reference calculations. Optimal energies as well as spectra for mammography with silicon detectors were determined by maximizing the figure of merit of a realistic imaging set-up. The scattered to primary radiation ratio was studied for various detector geometries. It was found that fan-shaped detectors are needed to maintain the image quality for divergent photon beams. (author)

Performance of a micro-strip gas chamber in solution X-ray scattering

CERN Document Server

Toyokawa, H; Inoko, Y; Nagayoshi, T; Nishi, Y; Nishikawa, Y; Ochi, A; Suzuki, M; Tanimori, T

2001-01-01

The performance of a Micro-Strip Gas Chamber in solution X-ray scattering was studied at the RIKEN structural biology beamline I of the SPring-8 facility. The practical dynamic range was confirmed to be approx 1,000,000 : 1 by measuring S sup - sup 4 decay from a polystyrene latex solution. Steep troughs of scattering profile from an apoferritin solution were clearly obtained without smearing. An unfolding process of a pH jump of cytochrome c was measured. A time resolution of 500 mu s was achieved.

Analysis of Resonance Response Performance of C-Band Antenna Using Parasitic Element

Science.gov (United States)

Islam, M. T.; Misran, N.; Mandeep, J. S.

2014-01-01

Analysis of the resonance response improvement of a planar C-band (4–8 GHz) antenna is proposed using parasitic element method. This parasitic element based method is validated for change in the active and parasitic antenna elements. A novel dual-band antenna for C-band application covering 5.7 GHz and 7.6 GHz is designed and fabricated. The antenna is composed of circular parasitic element with unequal microstrip lines at both sides and a rectangular partial ground plane. A fractional bandwidth of 13.5% has been achieved from 5.5 GHz to 6.3 GHz (WLAN band) for the lower band. The upper band covers from 7.1 GHz to 8 GHz with a fractional bandwidth of 12%. A gain of 6.4 dBi is achieved at the lower frequency and 4 dBi is achieved at the upper frequency. The VSWR of the antenna is less than 2 at the resonance frequency. PMID:24895643

Conduction noise absorption by ITO thin films attached to microstrip line utilizing Ohmic loss

International Nuclear Information System (INIS)

Kim, Sun-Hong; Kim, Sung-Soo

2010-01-01

For the aim of wide-band noise absorbers with a special design for low frequency performance, this study proposes conductive indium-tin oxide (ITO) thin films as the absorbent materials in microstrip line. ITO thin films were deposited on the polyimide film substrates by rf magnetron cosputtering of In 2 O 3 and Sn targets. The deposited ITO films show a typical value of electrical resistivity (∼10 -4 Ω m) and sheet resistance can be controlled in the range of 20-230 Ω by variation in film thickness. Microstrip line with characteristic impedance of 50 Ω was used for determining their noise absorbing properties. It is found that there is an optimum sheet resistance of ITO films for the maximum power absorption. Reflection parameter (S 11 ) is increased with decrease in sheet resistance due to impedance mismatch. On the while, transmission parameter (S 21 ) is decreased with decrease in sheet resistance due to larger Ohmic loss of the ITO films. Experimental results and computational prediction show that the optimum sheet resistance is about 100 Ω. For this film, greater power absorption is predicted in the lower frequency region than ferrite thin films of high magnetic loss, which indicates that Ohmic loss is the predominant loss parameter for power absorption in the low frequency range.

The Silicon Microstrip Sensors of the ATLAS SemiConductor Tracker

CERN Document Server

Ahmad, A; Allport, P P; Alonso, J; Andricek, L; Apsimon, R J; Barr, A J; Bates, R L; Beck, G A; Bell, P J; Belymam, A; Benes, J; Berg, C M; Bernabeu, J; Bethke, S; Bingefors, N; Bizzell, J P; Bohm, J; Brenner, R; Brodbeck, T J; Bruckman De Renstrom, P; Buttar, C M; Campbell, D; Carpentieri, C; Carter, A A; Carter, J R; Charlton, D G; Casse, G-L; Chilingarov, A; Cindro, V; Ciocio, A; Civera, J V; Clark, A G; Colijn, A-P; Costa, M J; Dabrowski, W; Danielsen, K M; Dawson, I; Demirkoz, B; Dervan, P; Dolezal, Z; Dorholt, O; Duerdoth, I P; Dwuznik, M; Eckert, S; Ekelöf, T; Eklund, L; Escobar, C; Fasching, D; Feld, L; Ferguson, D P S; Ferrere, D; Fortin, R; Foster, J M; Fox, H; French, R; Fromant, B P; Fujita, K; Fuster, J; Gadomski, S; Gallop, B J; Garcia, C; Garcia-Navarro, J E; Gibson, M D; Gonzalez, S; Gonzalez-Sevilla, S; Goodrick, M J; Gornicki, E; Green, C; Greenall, A; Grigson, C; Grillo, A A; Grosse-Knetter, J; Haber, C; Handa, T; Hara, K; Harper, R S; Hartjes, F G; Hashizaki, T; Hauff, D; Hessey, N P; Hill, J C; Hollins, T I; Holt, S; Horazdovsky, T; Hornung, M; Hovland, K M; Hughes, G; Huse, T; Ikegami, Y; Iwata, Y; Jackson, J N; Jakobs, K; Jared, R C; Johansen, L G; Jones, R W L; Jones, T J; de Jong, P; Joseph, J; Jovanovic, P; Kaplon, J; Kato, Y; Ketterer, C; Kindervaag, I M; Kodys, P; Koffeman, E; Kohriki, T; Kohout, Z; Kondo, T; Koperny, S; van der Kraaij, E; Kral, V; Kramberger, G; Kudlaty, J; Lacasta, C; Limper, M; Linhart, V; Llosa, G; Lozano, M; Ludwig, I; Ludwig, J; Lutz, G; Macpherson, A; McMahon, S J; Macina, D; Magrath, C A; Malecki, P; Mandic, I; Marti-Garcia, S; Matsuo, T; Meinhardt, J; Mellado, B; Mercer, I J; Mikestikova, M; Mikuz, M; Minano, M; Mistry, J; Mitsou, V; Modesto, P; Mohn, B; Molloy, S D; Moorhead, G; Moraes, A; Morgan, D; Morone, M C; Morris, J; Moser, H-G; Moszczynski, A; Muijs, A J M; Nagai, K; Nakamura, Y; Nakano, I; Nicholson, R; Niinikoski, T; Nisius, R; Ohsugi, T; O'Shea, V; Oye, O K; Parzefall, U; Pater, J R; Pernegger, H; Phillips, P W; Posisil, S; Ratoff, P N; Reznicek, P; Richardson, J D; Richter, R H; Robinson, D; Roe, S; Ruggiero, G; Runge, K; Sadrozinski, H F W; Sandaker, H; Schieck, J; Seiden, A; Shinma, S; Siegrist, J; Sloan, T; Smith, N A; Snow, S W; Solar, M; Solberg, A; Sopko, B; Sospedra, L; Spieler, H; Stanecka, E; Stapnes, S; Stastny, J; Stelzer, F; Stradling, A; Stugu, B; Takashima, R; Tanaka, R; Taylor, G; Terada, S; Thompson, R J; Titov, M; Tomeda, Y; Tovey, D R; Turala, M; Turner, P R; Tyndel, M; Ullan, M; Unno, Y; Vickey, T; Vos, M; Wallny, R; Weilhammer, P; Wells, P S; Wilson, J A; Wolter, M; Wormald, M; Wu, S L; Yamashita, T; Zontar, D; Zsenei, A

2007-01-01

This paper describes the AC-coupled, single-sided, p-in-n silicon microstrip sensors used in the SemiConductor Tracker (SCT) of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The sensor requirements, specifications and designs are discussed, together with the qualification and quality assurance procedures adopted for their production. The measured sensor performance is presented, both initially and after irradiation to the fluence anticipated after 10 years of LHC operation. The sensors are now successfully assembled within the detecting modules of the SCT, and the SCT tracker is completed and integrated within the ATLAS Inner Detector. Hamamatsu Photonics Ltd supplied 92.2% of the 15,392 installed sensors, with the remainder supplied by CiS.

Polarization-Insensitive Tunable Optical Filters based on Liquid Crystal Polarization Gratings

Science.gov (United States)

Nicolescu, Elena

Tunable optical filters are widely used for a variety of applications including spectroscopy, optical communication networks, remote sensing, and biomedical imaging and diagnostics. All of these application areas can greatly benefit from improvements in the key characteristics of the tunable optical filters embedded in them. Some of these key parameters include peak transmittance, bandwidth, tuning range, and transition width. In recent years research efforts have also focused on miniaturizing tunable optical filters into physically small packages for compact portable spectroscopy and hyperspectral imaging applications such as real-time medical diagnostics and defense applications. However, it is important that miniaturization not have a detrimental effect on filter performance. The overarching theme of this dissertation is to explore novel configurations of Polarization Gratings (PGs) as simple, low-cost, polarization-insensitive alternatives to conventional optical filtering technologies for applications including hyperspectral imaging and telecommunications. We approach this goal from several directions with a combination of theory and experimental demonstration leading to, in our opinion, a significant contribution to the field. We present three classes of tunable optical filters, the first of which is an angle-filtering scheme where the stop-band wavelengths are redirected off axis and the passband is transmitted on-axis. This is achieved using a stacked configuration of polarization gratings of various thicknesses. To improve this class of filter, we also introduce a novel optical element, the Bilayer Polarization Grating, exhibiting unique optical properties and demonstrating complex anchoring conditions with high quality. The second class of optical filter is analogous to a Lyot filter, utilizing stacks of static or tunable waveplates sandwiched with polarizing elements. However, we introduce a new configuration using PGs and static waveplates to replace

Dual polarized receiving steering antenna array for measurement of ultrawideband pulse polarization structure

Energy Technology Data Exchange (ETDEWEB)

Balzovsky, E. V.; Buyanov, Yu. I.; Koshelev, V. I., E-mail: koshelev@lhfe.hcei.tsc.ru; Nekrasov, E. S. [Institute of High Current Electronics SB RAS, IHCE SB RAS, Tomsk 634055 (Russian Federation)

2016-03-15

To measure simultaneously two orthogonal components of the electromagnetic field of nano- and subnano-second duration, an antenna array has been developed. The antenna elements of the array are the crossed dipoles of dimension 5 × 5 cm. The arms of the dipoles are connected to the active four-pole devices to compensate the frequency response variations of a short dipole in the frequency band ranging from 0.4 to 4 GHz. The dipoles have superimposed phase centers allowing measuring the polarization structure of the field in different directions. The developed antenna array is the linear one containing four elements. The pattern maximum position is controlled by means of the switched ultrawideband true time delay lines. Discrete steering in seven directions in the range from −40° to +40° has been realized. The error at setting the pattern maximum position is less than 4°. The isolation of the polarization exceeds 29 dB in the direction orthogonal to the array axis and in the whole steering range it exceeds 23 dB. Measurement results of the polarization structure of radiated and scattered pulses with different polarization are presented as well.

Research on the Scattering Characteristics and the RCS Reduction of Circularly Polarized Microstrip Antenna

Directory of Open Access Journals (Sweden)

W. Jiang

2013-01-01

Full Text Available Based on the study of the radiation and scattering of the circularly polarized (CP antenna, a novel radar cross-section (RCS reduction technique is proposed for CP antenna in this paper. Quasi-fractal slots are applied in the design of the antenna ground plane to reduce the RCS of the CP antenna. Both prototype antenna and array are designed, and their time-, frequency-, and space-domain characteristics are studied to authenticate the proposed technique. The simulated and measured results show that the RCS of the prototype antenna and array is reduced up to 7.85 dB and 6.95 dB in the band of 1 GHz–10 GHz. The proposed technique serves a candidate in the design of low RCS CP antennas and arrays.

Design and characterization of integrated front-end transistors in a micro-strip detector technology

International Nuclear Information System (INIS)

Simi, G.; Angelini, C.; Batignani, G.; Bettarini, S.; Bondioli, M.; Boscardin, M.; Bosisio, L.; Dalla Betta, G.-F.; Dittongo, S.; Forti, F.; Giorgi, M.; Gregori, P.; Manghisoni, M.; Morganti, M.; U. Pignatel, G.; Ratti, L.; Re, V.; Rizzo, G.; Speziali, V.; Zorzi, N.

2002-01-01

We present the developments in a research program aimed at the realization of silicon micro-strip detectors with front-end electronics integrated in a high resistivity substrate to be used in high-energy physics, space and medical/industrial imaging applications. We report on the fabrication process developed at IRST (Trento, Italy), the characterization of the basic wafer parameters and measurements of the relevant working characteristics of the integrated transistors and related test structures

Polarization-dependent thin-film wire-grid reflectarray for terahertz waves

Energy Technology Data Exchange (ETDEWEB)

Niu, Tiaoming [School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide, South Australia 5005 (Australia); School of Information Science and Engineering, Lanzhou University, Lanzhou 730000 (China); Upadhyay, Aditi; Bhaskaran, Madhu; Sriram, Sharath [Functional Materials and Microsystems Research Group, RMIT University, Melbourne, Victoria 3001 (Australia); Withayachumnankul, Withawat [School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide, South Australia 5005 (Australia); Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-S9-3, Ookayama, Meguro-ku, Tokyo 152-8552 (Japan); Headland, Daniel; Abbott, Derek; Fumeaux, Christophe, E-mail: cfumeaux@eleceng.adelaide.edu.au [School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide, South Australia 5005 (Australia)

2015-07-20

A thin-film polarization-dependent reflectarray based on patterned metallic wire grids is realized at 1 THz. Unlike conventional reflectarrays with resonant elements and a solid metal ground, parallel narrow metal strips with uniform spacing are employed in this design to construct both the radiation elements and the ground plane. For each radiation element, a certain number of thin strips with an identical length are grouped to effectively form a patch resonator with equivalent performance. The ground plane is made of continuous metallic strips, similar to conventional wire-grid polarizers. The structure can deflect incident waves with the polarization parallel to the strips into a designed direction and transmit the orthogonal polarization component. Measured radiation patterns show reasonable deflection efficiency and high polarization discrimination. Utilizing this flexible device approach, similar reflectarray designs can be realized for conformal mounting onto surfaces of cylindrical or spherical devices for terahertz imaging and communications.

Metasurface Reflector (MSR) Loading for High Performance Small Microstrip Antenna Design.

Science.gov (United States)

Ahsan, Md Rezwanul; Islam, Mohammad Tariqul; Ullah, Mohammad Habib; Singh, Mandeep Jit; Ali, Mohd Tarmizi

2015-01-01

A meander stripline feed multiband microstrip antenna loaded with metasurface reflector (MSR) structure has been designed, analyzed and constructed that offers the wireless communication services for UHF/microwave RFID and WLAN/WiMAX applications. The proposed MSR assimilated antenna comprises planar straight forward design of circular shaped radiator with horizontal slots on it and 2D metasurface formed by the periodic square metallic element that resembles the behavior of metamaterials. A custom made high dielectric bio-plastic substrate (εr = 15) is used for fabricating the prototype of the MSR embedded planar monopole antenna. The details of the design progress through numerical simulations and experimental results are presented and discussed accordingly. The measured impedance bandwidth, radiation patterns and gain of the proposed MSR integrated antenna are compared with the obtained results from numerical simulation, and a good compliance can be observed between them. The investigation shows that utilization of MSR structure has significantly broadened the -10 dB impedance bandwidth than the conventional patch antenna: from 540 to 632 MHz (17%), 467 to 606 MHz (29%) and 758 MHz to 1062 MHz (40%) for three distinct operating bands centered at 0.9, 3.5 and 5.5 GHz. Additionally, due to the assimilation of MSR, the overall realized gains have been upgraded to a higher value of 3.62 dBi, 6.09 dBi and 8.6 dBi for lower, middle and upper frequency band respectively. The measured radiation patterns, impedance bandwidths (S11WLAN (5.2/5.8 GHz) applications.

ATLAS Silicon Microstrip Tracker Operation and Performance

CERN Document Server

Chalupkova, I; The ATLAS collaboration

2012-01-01

The Semi-Conductor Tracker (SCT) is a silicon strip detector and one of the key precision tracking devices in the Inner Detector of the ATLAS experiment at CERN LHC. The SCT is constructed of 4088 silicon detector modules for a total of 6.3 million strips. Each module is designed, constructed and tested to operate as a stand-alone unit, mechanically, electrically, optically and thermally. The modules are mounted into two types of structures: one barrel (4 cylinders) and two end-cap systems (9 disks on each end of the barrel). The SCT silicon micro-strip sensors are processed in the planar p-in-n technology. The signals from the strips are processed in the front-end ASICS ABCD3TA, working in the binary readout mode. Data is transferred to the off-detector readout electronics via optical fibers. The completed SCT has been installed inside the ATLAS experimental cavern since 2007 and has been operational since then. Calibration data has been taken regularly and analyzed to determine the noise performance of the ...

ATLAS Silicon Microstrip Tracker Operation and Performance

CERN Document Server

NAGAI, K; The ATLAS collaboration

2012-01-01

The Semi-Conductor Tracker (SCT) is a silicon strip detector and one of the key precision tracking devices in the Inner Detector of the ATLAS experiment at CERN LHC. The SCT is constructed of 4088 silicon detector modules for a total of 6.3 million strips. Each module is designed, constructed and tested to operate as a stand-alone unit, mechanically, electrically, optically and thermally. The modules are mounted into two types of structures: one barrel (4 cylinders) and two end-cap systems (9 disks on each end of the barrel). The SCT silicon micro-strip sensors are processed in the planar p-in-n technology. The signals from the strips are processed in the front-end ASICS ABCD3TA, working in the binary readout mode. Data is transferred to the off-detector readout electronics via optical fibres. The completed SCT has been installed inside the ATLAS experimental cavern since 2007 and has been operational since then. Calibration data has been taken regularly and analysed to determine the noise performance of the ...

ATLAS Silicon Microstrip Tracker Operation and Performance

CERN Document Server

Chalupkova, I; The ATLAS collaboration

2012-01-01

The Semi-Conductor Tracker (SCT) is a silicon strip detector and one of the key precision tracking devices in the Inner Detector (ID) of the ATLAS experiment at CERN LHC. The SCT is constructed of 4088 silicon detector modules with a total of 6.3 million strips. Each module is designed, constructed and tested to operate as a stand-alone unit, mechanically, electrically, optically and thermally. The modules are mounted into two types of structures: one barrel (4 cylinders) and two end-cap systems (9 disks on each side of the barrel). The SCT silicon microstrip sensors are processed in the planar p-in-n technology. The signals from the strips are processed in the front-end ASICs ABCD3TA, working in the binary readout mode. Data is transferred to the off-detector readout electronics via optical fibres. SCT has been installed inside the ATLAS experimental cavern since 2007 and has been operational ever since. Calibration data has been taken regularly and analysed to determine the noise performance of the system. ...

Coherent active polarization control without loss

Science.gov (United States)

Ye, Yuqian; Hay, Darrick; Shi, Zhimin

2017-11-01

We propose a lossless active polarization control mechanism utilizing an anisotropic dielectric medium with two coherent inputs. Using scattering matrix analysis, we derive analytically the required optical properties of the anisotropic medium that can behave as a switchable polarizing beam splitter. We also show that such a designed anisotropic medium can produce linearly polarized light at any azimuthal direction through coherent control of two inputs with a specific polarization state. Furthermore, we present a straightforward design-on-demand procedure of a subwavelength-thick metastructure that can possess the desired optical anisotropy at a flexible working wavelength. Our lossless coherent polarization control technique may lead to fast, broadband and integrated polarization control elements for applications in imaging, spectroscopy, and telecommunication.

Instrumentation with polarized neutrons

International Nuclear Information System (INIS)

Boeni, P.; Muenzer, W.; Ostermann, A.

2009-01-01

Neutron scattering with polarization analysis is an indispensable tool for the investigation of novel materials exhibiting electronic, magnetic, and orbital degrees of freedom. In addition, polarized neutrons are necessary for neutron spin precession techniques that path the way to obtain extremely high resolution in space and time. Last but not least, polarized neutrons are being used for fundamental studies as well as very recently for neutron imaging. Many years ago, neutron beam lines were simply adapted for polarized beam applications by adding polarizing elements leading usually to unacceptable losses in neutron intensity. Recently, an increasing number of beam lines are designed such that an optimum use of polarized neutrons is facilitated. In addition, marked progress has been obtained in the technology of 3 He polarizers and the reflectivity of large-m supermirrors. Therefore, if properly designed, only factors of approximately 2-3 in neutron intensity are lost. It is shown that S-benders provide neutron beams with an almost wavelength independent polarization. Using twin cavities, polarized beams with a homogeneous phase space and P>0.99 can be produced without significantly sacrificing intensity. It is argued that elliptic guides, which are coated with large m polarizing supermirrors, provide the highest flux.

A Butterfly-Shaped Wideband Microstrip Patch Antenna for Wireless Communication

Directory of Open Access Journals (Sweden)

Liling Sun

2015-01-01

Full Text Available A novel butterfly-shaped patch antenna for wireless communication is introduced in this paper. The antenna is designed for wideband wireless communications and radio-frequency identification (RFID systems. Two symmetrical quasi-circular arms and two symmetrical round holes are incorporated into the patch of a microstrip antenna to expand its bandwidth. The diameter and position of the circular slots are optimized to achieve a wide bandwidth. The validity of the design concept is demonstrated by means of a prototype having a bandwidth of about 40.1%. The return loss of the butterfly-shaped antenna is greater than 10 dB between 4.15 and 6.36 GHz. The antenna can serve simultaneously most of the modern wireless communication standards.

Computer simulation and implementation of defected ground structure on a microstrip antenna

Science.gov (United States)

Adrian, H.; Rambe, A. H.; Suherman

2018-03-01

Defected Ground Structure (DGS) is a method reducing etching area on antenna ground to form desirable antenna’s ground field. This paper reports the method impact on microstrip antennas working on 1800 and 2400 MHz. These frequencies are important as many radio network applications such mobile phones and wireless devices working on these channels. The assessments were performed by simulating and fabricating the evaluated antennas. Both simulation data and implementation measurements show that DGS successfully improves antenna performances by increasing bandwidth up to 19%, reducing return loss up to 109% and increasing gain up to 33%.

Frequency selective surfaces based high performance microstrip antenna

CERN Document Server

Narayan, Shiv; Jha, Rakesh Mohan

2016-01-01

This book focuses on performance enhancement of printed antennas using frequency selective surfaces (FSS) technology. The growing demand of stealth technology in strategic areas requires high-performance low-RCS (radar cross section) antennas. Such requirements may be accomplished by incorporating FSS into the antenna structure either in its ground plane or as the superstrate, due to the filter characteristics of FSS structure. In view of this, a novel approach based on FSS technology is presented in this book to enhance the performance of printed antennas including out-of-band structural RCS reduction. In this endeavor, the EM design of microstrip patch antennas (MPA) loaded with FSS-based (i) high impedance surface (HIS) ground plane, and (ii) the superstrates are discussed in detail. The EM analysis of proposed FSS-based antenna structures have been carried out using transmission line analogy, in combination with the reciprocity theorem. Further, various types of novel FSS structures are considered in desi...

Highly Sensitive Reentrant Cavity-Microstrip Patch Antenna Integrated Wireless Passive Pressure Sensor for High Temperature Applications

Directory of Open Access Journals (Sweden)

Fei Lu

2017-01-01

Full Text Available A novel reentrant cavity-microstrip patch antenna integrated wireless passive pressure sensor was proposed in this paper for high temperature applications. The reentrant cavity was analyzed from aspects of distributed model and equivalent lumped circuit model, on the basis of which an optimal sensor structure integrated with a rectangular microstrip patch antenna was proposed to better transmit/receive wireless signals. In this paper, the proposed sensor was fabricated with high temperature resistant alumina ceramic and silver metalization with weld sealing, and it was measured in a hermetic metal tank with nitrogen pressure loading. It was verified that the sensor was highly sensitive, keeping stable performance up to 300 kPa with an average sensitivity of 981.8 kHz/kPa at temperature 25°C, while, for high temperature measurement, the sensor can operate properly under pressure of 60–120 kPa in the temperature range of 25–300°C with maximum pressure sensitivity of 179.2 kHz/kPa. In practical application, the proposed sensor is used in a method called table lookup with a maximum error of 5.78%.

Broadband Circularly Polarized Slot Antenna Loaded by a Multiple-Circular-Sector Patch.

Science.gov (United States)

Trinh-Van, Son; Yang, Youngoo; Lee, Kang-Yoon; Hwang, Keum Cheol

2018-05-15

In this paper, a microstrip-fed broadband circularly polarized (CP) slot antenna is presented. CP operation can be attained simply by embedding an S-shaped strip. By loading with a multiple-circular-sector patch, which consists of 12 circular-sector patches with identical central angles of 30° and different radii, the 3 dB axial ratio (AR) bandwidth is significantly broadened. To validate the performance of the proposed antenna, an antenna prototype is fabricated and tested. The fabricated antenna is 54 mm × 54 mm × 0.8 mm in size. The measured -10 dB reflection and 3 dB AR bandwidths are 81.06% (1.68⁻3.97 GHz) and 70.55% (1.89⁻3.95 GHz), respectively. Within the 3 dB AR bandwidth, the measured peak gain is 3.81 dBic. Reasonable agreement is also obtained between the measured and simulated results.

New results on silicon microstrip detectors of CMS tracker

International Nuclear Information System (INIS)

Demaria, N.; Albergo, S.; Angarano, M.; Azzi, P.; Babucci, E.; Bacchetta, N.; Bader, A.; Bagliesi, G.; Basti, A.; Biggeri, U.; Bilei, G.M.; Bisello, D.; Boemi, D.; Bolla, G.; Bosi, F.; Borrello, L.; Bortoletto, D.; Bozzi, C.; Braibant, S.; Breuker, H.; Bruzzi, M.; Buffini, A.; Busoni, S.; Candelori, A.; Caner, A.; Castaldi, R.; Castro, A.; Catacchini, E.; Checcucci, B.; Ciampolini, P.; Civinini, C.; Creanza, D.; D'Alessandro, R.; Da Rold, M.; De Palma, M.; Dell'Orso, R.; Marina, R. Della; Dutta, S.; Eklund, C.; Elliott-Peisert, A.; Favro, G.; Feld, L.; Fiore, L.; Focardi, E.; French, M.; Freudenreich, K.; Fuertjes, A.; Giassi, A.; Giorgi, M.; Giraldo, A.; Glessing, B.; Gu, W.H.; Hall, G.; Hammerstrom, R.; Hebbeker, T.; Hrubec, J.; Huhtinen, M.; Kaminsky, A.; Karimaki, V.; Koenig, St.; Krammer, M.; Lariccia, P.; Lenzi, M.; Loreti, M.; Luebelsmeyer, K.; Lustermann, W.; Maettig, P.; Maggi, G.; Mannelli, M.; Mantovani, G.; Marchioro, A.; Mariotti, C.; Martignon, G.; Evoy, B. Mc; Meschini, M.; Messineo, A.; Migliore, E.; My, S.; Paccagnella, A.; Palla, F.; Pandoulas, D.; Papi, A.; Parrini, G.; Passeri, D.; Pieri, M.; Piperov, S.; Potenza, R.; Radicci, V.; Raffaelli, F.; Raymond, M.; Santocchia, A.; Schmitt, B.; Selvaggi, G.; Servoli, L.; Sguazzoni, G.; Siedling, R.; Silvestris, L.; Skog, K.; Starodumov, A.; Stavitski, I.; Stefanini, G.; Tempesta, P.; Tonelli, G.; Tricomi, A.; Tuuva, T.; Vannini, C.; Verdini, P.G.; Viertel, G.; Xie, Z.; Li Yahong; Watts, S.; Wittmer, B.

2000-01-01

Interstrip and backplane capacitances on silicon microstrip detectors with p + strip on n substrate of 320 μm thickness were measured for pitches between 60 and 240 μm and width over pitch ratios between 0.13 and 0.5. Parametrisations of capacitance w.r.t. pitch and width were compared with data. The detectors were measured before and after being irradiated to a fluence of 4x10 14 protons/cm 2 of 24 GeV/c momentum. The effect of the crystal orientation of the silicon has been found to have a relevant influence on the surface radiation damage, favouring the choice of a substrate. Working at high bias (up to 500 V in CMS) might be critical for the stability of detector, for a small width over pitch ratio. The influence found to enhance the stability

Fragmentation functions of polarized heavy quarkonium

International Nuclear Information System (INIS)

Ma, Yan-Qing; Qiu, Jian-Wei; Zhang, Hong

2015-01-01

Investigating the production of polarized heavy quarkonia in terms of recently proposed QCD factorization formalism requires the knowledge of a large number of input fragmentation functions (FFs) from a single parton or a heavy quark-antiquark pair to a polarized heavy quarkonium. We study these universal FFs at the input factorization scale μ 0 ≳2m Q , with heavy quark mass m Q , in the framework of nonrelativistic QCD (NRQCD) factorization. We express these FFs in terms of perturbatively calculable coefficients for producing a heavy quark-antiquark pair in all possible NRQCD states, multiplied by corresponding NRQCD long-distance matrix elements for the pair to transmute into a polarized heavy quarkonium. We derive all relevant NRQCD operators for the long-distance matrix elements based on symmetries, and introduce a self-consistent scheme to define them in arbitrary d-dimensions. We compute, up to the first non-trivial order in α s , the perturbative coefficients for producing a heavy quark pair in all possible S-wave and P-wave NRQCD states. We also discuss the role of the polarized FFs in generating QCD predictions for the polarization of J/ψ produced at collider energies.

Investigation of DC current injection effect on the microwave characteristics of HTS YBCO microstrip resonators

Energy Technology Data Exchange (ETDEWEB)

Nurgaliev, T., E-mail: timur@ie.bas.bg [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria); Blagoev, B.; Mateev, E.; Neshkov, L. [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria); Strbik, V. [Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, 841 04 Bratislava (Slovakia); Uspenskaya, L. [Institute of Solid State Physics, Russian Academy of Sciences, 142432 Chernogolovka, Moscow (Russian Federation); Nedkov, I. [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria); Chromik, Š. [Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, 841 04 Bratislava (Slovakia)

2014-03-15

Highlights: • Current (spin) injection effect in LSMO/YBCO was studied by impedance measurements. • Complex impedance of YBCO increases at current injection from LSMO to YBCO at 77 K. • This increase is due to an increase of the quasiparticle conductivity of YBCO. • Injection does not significantly affect the relaxation time of the quasiparticles. - Abstract: The DC current injection effect from a ferromagnetic (FM) La{sub 0.7}Sr{sub 0.3}MnO{sub 3} (LSMO) to a high temperature superconducting (HTS) Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7−x} (YBCO) thin film was investigated by the microwave surface impedance measurements in a FM/HTS structure, formed as a microstrip resonator for improving the sensitivity of the experiments. The quality factor and the resonance frequency of this structure were found to strongly depend on the current strength, injected from the LSMO electrode into the HTS microstrip electrode. The magnetic penetration depth and the quasiparticle conductivity of the HTS component were determined to increase under DC current injection process, which in all probability stimulated breaking of Cooper pairs and led to a decrease of the superfluid concentration and an increase of the normal fluid concentration without significantly affecting the relaxation time of the quasiparticles.

Voltage-carrying states in superconducting microstrips

International Nuclear Information System (INIS)

Stuivinga, M.E.C.

1983-01-01

When the critical current is exceeded in a superconducting microstrip, voltage-carrying states with a resistance significantly below the normal state resistance can occur. Phase-slip centers (PSC) appear at about the critical temperature. These are successive local voltage units which manifest themselves as strip-like increments in voltage in the I-V characteristic. For temperatures off the critical temperature the PSC regime degenerates into a region of normal material, a so-called hot spot. These two phenomena, PSC and hot spots, form the subject of this thesis. To gain a better understanding of the phase-slip center process, an experiment was designed to measure local values of the quasi-particle and pair potential. The results of local potential and gap measurements at a PSC in aluminium are presented and discussed. Special attention is paid to pair-breaking interactions which can shorten the relaxation time. A non-linear differential equation is derived which describes the development of a PSC into a normal hot spot under the influence of Joule heating. It incorporates the temperature rise due to the dissipative processes occurring in the charge imbalance tails. Numerical solutions are presented for a set of parameters, including those for aluminium and tin. Subsequently, they are compared with experiments. (Auth.)

Analysis of High Tc Superconducting Rectangular Microstrip Patches over Ground Planes with Rectangular Apertures in Substrates Containing Anisotropic Materials

Directory of Open Access Journals (Sweden)

Abderraouf Messai

2013-01-01

Full Text Available A rigorous full-wave analysis of high Tc superconducting rectangular microstrip patch over ground plane with rectangular aperture in the case where the patch is printed on a uniaxially anisotropic substrate material is presented. The dyadic Green’s functions of the considered structure are efficiently determined in the vector Fourier transform domain. The effect of the superconductivity of the patch is taken into account using the concept of the complex resistive boundary condition. The accuracy of the analysis is tested by comparing the computed results with measurements and previously published data for several anisotropic substrate materials. Numerical results showing variation of the resonant frequency and the quality factor of the superconducting antenna with regard to operating temperature are given. Finally, the effects of uniaxial anisotropy in the substrate on the resonant frequencies of different TM modes of the superconducting microstrip antenna with rectangular aperture in the ground plane are presented.

Microstrip silicon detectors of the monitoring and triggering systems in the E-161 experiment

International Nuclear Information System (INIS)

Bogolyubskij, M.Yu.; Kurchaninov, L.L.; Moiseev, A.M.; Semenov, P.A.; Leflat, A.K.; Sekhniaidze, G.G.

1991-01-01

A monitoring and triggering system based on microstrip silicon detectors (MSD) and fast-response low-noise electronics with the number of the readout channels equal to 896, is described. The PMS noise is ENC=25x10 3 e - with the signal integration time of 50 ns. The probability of registering a noise pulse by one channel during data readout cycle is not more than 2.5x10 -6 . The time resolution (FWHM) is (16±3) ns. 17 refs.; 7 figs

Design, fabrication and characterization of the first AC-coupled silicon microstrip sensors in India

CERN Document Server

Aziz, T; Mohanty, G.B.; Patil, M.R.; Rao, K.K.; Rani, Y.R.; Rao, Y.P.P.; Behnamian, H.; Mersi, S.; Naseri, M.

2014-01-01

This paper reports the design, fabrication and characterization of single-sided silicon microstrip sensors with integrated biasing resistors and coupling capacitors, produced for the first time in India. We have first developed a prototype sensor with different width and pitch combinations on a single 4-inch wafer. After finding test procedures for characterizing these AC coupled sensors, we have chosen an optimal width-pitch combination and also fine-tuned various process parameters in order to produce sensors with the desired specifications.

Performance characteristics and radiation damage results from the Fermilab E706 silicon microstrip detector system

Energy Technology Data Exchange (ETDEWEB)

Engels, E Jr; Mani, S; Orris, D; Shepard, P F; Weerasundara, P D; Choudhary, B C; Joshi, U; Kapoor, V; Shivpuri, R; Baker, W

1989-07-01

A charged particle spectrometer containing a 7120-channel silicon microstrip detector system, one component of Fermilab experiment E706 to study direct photon production in hadron-hadron collisions, was utilized in a run in which 6 million events were recorded. We describe the silicon system, provide early results of track and vertex reconstruction, and present data on the radiation damage to the silicon wafers resulting from the narrow high intensity beam. (orig.).

Coherent active polarization control without loss

Directory of Open Access Journals (Sweden)

Yuqian Ye

2017-11-01

Full Text Available We propose a lossless active polarization control mechanism utilizing an anisotropic dielectric medium with two coherent inputs. Using scattering matrix analysis, we derive analytically the required optical properties of the anisotropic medium that can behave as a switchable polarizing beam splitter. We also show that such a designed anisotropic medium can produce linearly polarized light at any azimuthal direction through coherent control of two inputs with a specific polarization state. Furthermore, we present a straightforward design-on-demand procedure of a subwavelength-thick metastructure that can possess the desired optical anisotropy at a flexible working wavelength. Our lossless coherent polarization control technique may lead to fast, broadband and integrated polarization control elements for applications in imaging, spectroscopy, and telecommunication.

Quarkonium polarization and the long distance matrix elements hierarchies using jet substructure

Science.gov (United States)

Dai, Lin; Shrivastava, Prashant

2017-08-01

We investigate the quarkonium production mechanisms in jets at the LHC, using the fragmenting jet functions (FJF) approach. Specifically, we discuss the jet energy dependence of the J /ψ production cross section at the LHC. By comparing the cross sections for the different NRQCD production channels (1S0[8], 3S1[8], 3PJ[8], and 3cripts>S1[1]), we find that at fixed values of energy fraction z carried by the J /ψ , if the normalized cross section is a decreasing function of the jet energy, in particular for z >0.5 , then the depolarizing 1S0[8] must be the dominant channel. This makes the prediction made in [Baumgart et al., J. High Energy Phys. 11 (2014) 003, 10.1007/JHEP11(2014)003] for the FJF's also true for the cross section. We also make comparisons between the long distance matrix elements extracted by various groups. This analysis could potentially shed light on the polarization properties of the J /ψ production in high pT region.

Using graphene/styrene-isoprene-styrene copolymer composite thin film as a flexible microstrip antenna for the detection of heptane vapors

Science.gov (United States)

Olejnik, Robert; Matyas, Jiri; Slobodian, Petr; Riha, Pavel

2018-03-01

Most portable devices, such as mobile phones or tablets, use antennas made of copper. This paper demonstrates the possible use of antenna constructed from electrically conductive polymer composite materials for use in those applications. The method of preparation and the properties of the graphene/styrene-isoprene-styrene copolymer as flexible microstrip antenna are described in this contribution. Graphene/styrene-isoprene-styrene copolymer toluene solution was prepared by means of ultrasound and the PET substrate was dip coated to reach a fine thin film. The main advantages of using PET as a substrate are low weight and flexibility. The final size of the flexible microstrip antenna was 10 × 25 mm with thickness of 0.48 mm (PET substrate 0.25 mm) with a weight of 0.110 g. The resulting antenna operates at a frequency of 1.8 GHz and gain ‑40.02 dB.

A Mobile Communications Space Link Between the Space Shuttle Orbiter and the Advanced Communications Technology Satellite

Science.gov (United States)

Fink, Patrick; Arndt, G. D.; Bondyopadhyay, P.; Shaw, Roland

1994-01-01

A communications experiment is described as a link between the Space Shuttle Orbiter (SSO) and the Advanced Communications Technology Satellite (ACTS). Breadboarding for this experiment has led to two items with potential for commercial application: a 1-Watt Ka-band amplifier and a Ka-band, circularly polarized microstrip antenna. Results of the hybrid Ka-band amplifier show gain at 30 dB and a saturated output power of 28.5 dBm. A second version comprised of MMIC amplifiers is discussed. Test results of the microstrip antenna subarray show a gain of approximately 13 dB and excellent circular polarization.

Initial investigations of the performance of a microstrip gas-avalanche chamber fabricated on a thin silicon-dioxide substrate

International Nuclear Information System (INIS)

Biagi, S.F.; Jackson, J.N.; Jones, T.J.; Taylor, S.

1992-01-01

We report on the construction of a micro-strip gas-avalanche chamber, designed such that the effective thickness of the insulating dielectric is ≅ 3 μm. Experimental results are presented on the initial observation of pulses from the chamber originating from the energy depositions of X-rays from an Fe 55 source. (orig.)

Optical system storage design with diffractive optical elements

Science.gov (United States)

Kostuk, Raymond K.; Haggans, Charles W.

1993-01-01

Optical data storage systems are gaining widespread acceptance due to their high areal density and the ability to remove the high capacity hard disk from the system. In magneto-optical read-write systems, a small rotation of the polarization state in the return signal from the MO media is the signal which must be sensed. A typical arrangement used for detecting these signals and correcting for errors in tracking and focusing on the disk is illustrated. The components required to achieve these functions are listed. The assembly and alignment of this complex system has a direct impact on cost, and also affects the size, weight, and corresponding data access rates. As a result, integrating these optical components and improving packaging techniques is an active area of research and development. Most designs of binary optic elements have been concerned with optimizing grating efficiency. However, rigorous coupled wave models for vector field diffraction from grating surfaces can be extended to determine the phase and polarization state of the diffracted field, and the design of polarization components. A typical grating geometry and the phase and polarization angles associated with the incident and diffracted fields are shown. In our current stage of work, we are examining system configurations which cascade several polarization functions on a single substrate. In this design, the beam returning from the MO disk illuminates a cascaded grating element which first couples light into the substrate, then introduces a quarter wave retardation, then a polarization rotation, and finally separates s- and p-polarized fields through a polarization beam splitter. The input coupler and polarization beam splitter are formed in volume gratings, and the two intermediate elements are zero-order elements.

The construction of a microstrip gas tracker for Hermes

International Nuclear Information System (INIS)

Brand, J. van den

1994-01-01

To measure the spin structure of the nucleon, the HERMES experiment is planned at the HERA electron beam using a polarised internal gas target. A tracker is being built to reconstruct the vertex of the exciting particles. It consists of two drift chambers and two microstrip gas counter (MSGC) systems. The MSGC systems are housed into two gas gatight containers surrounding the beam pipe and located immediately after the exit flange of the target housing. The active area of the upper MSGC system covers an angular range of 40 mrad≤θ v ≤ 140 mrad by -170 mrad≤θ h ≤170 mrad. Below the beam pipe a second system is situated with the same acceptance. Each track within the acceptance is measured by two stations of three MSCGs having a strip orientation, of 0 , and +30 and -30 respectively with respect to the vertical axis. (HSI)

The charge collection in single side silicon microstrip detectors

CERN Document Server

Eremin, V V; Roe, S; Ruggiero, G; Weilhammer, Peter

2003-01-01

The transient current technique has been used to investigate signal formation in unirradiated silicon microstrip detectors, which are similar in geometry to those developed for the ATLAS experiment at LHC. Nanosecond pulsed infrared and red lasers were used to induce the signals under study. Two peculiarities in the detector performance were observed: an unexpectedly slow rise to the signal induced in a given strip when signals are injected opposite to the strip, and a long duration of the induced signal in comparison with the calculated drift time of charge carriers through the detector thickness - with a significant fraction of the charge being induced after charge carrier arrival. These major effects and details of the detector response for different positions of charge injection are discussed in the context of Ramo's theorem and compared with predictions arising from the more commonly studied phenomenon of signal formation in planar pad detectors.

A Compact Narrow-Band Bandstop Filter Using Spiral-Shaped Defected Microstrip Structure

Directory of Open Access Journals (Sweden)

J. Wang

2014-04-01

Full Text Available A novel compact narrow-band bandstop filter is implemented by using the proposed spiral-shaped defected microstrip structure (SDMS in this paper. Compared with other DMSs, the presented SDMS exhibits the advantage of compact size and narrow stopband. Meanwhile, an approximate design rule of the SDMS is achieved and the effects of the dimensions on the resonant frequency and 3 dB fractional bandwidth (FBW are analyzed in detail. Both the simulation and measurement results of the fabricated bandstop filter show that it has a 10 dB stopband from 3.4 GHz to 3.6 GHz with more than 45 dB rejection at the center frequency.

Mechanically Reconfigurable Microstrip Lines Loaded with Stepped Impedance Resonators and Potential Applications

Directory of Open Access Journals (Sweden)

J. Naqui

2014-01-01

Full Text Available This paper is focused on exploring the possibilities and potential applications of microstrip transmission lines loaded with stepped impedance resonators (SIRs etched on top of the signal strip, in a separated substrate. It is shown that if the symmetry plane of the line (a magnetic wall is perfectly aligned with the electric wall of the SIR at the fundamental resonance, the line is transparent. However, if symmetry is somehow ruptured, a notch in the transmission coefficient appears. The notch frequency and depth can thus be mechanically controlled, and this property can be of interest for the implementation of sensors and barcodes, as it is discussed.

Microstrip resonators for electron paramagnetic resonance experiments

Science.gov (United States)

Torrezan, A. C.; Mayer Alegre, T. P.; Medeiros-Ribeiro, G.

2009-07-01

In this article we evaluate the performance of an electron paramagnetic resonance (EPR) setup using a microstrip resonator (MR). The design and characterization of the resonator are described and parameters of importance to EPR and spin manipulation are examined, including cavity quality factor, filling factor, and microwave magnetic field in the sample region. Simulated microwave electric and magnetic field distributions in the resonator are also presented and compared with qualitative measurements of the field distribution obtained by a perturbation technique. Based on EPR experiments carried out with a standard marker at room temperature and a MR resonating at 8.17 GHz, the minimum detectable number of spins was found to be 5×1010 spins/GHz1/2 despite the low MR unloaded quality factor Q0=60. The functionality of the EPR setup was further evaluated at low temperature, where the spin resonance of Cr dopants present in a GaAs wafer was detected at 2.3 K. The design and characterization of a more versatile MR targeting an improved EPR sensitivity and featuring an integrated biasing circuit for the study of samples that require an electrical contact are also discussed.

Microstrip resonators for electron paramagnetic resonance experiments.

Science.gov (United States)

Torrezan, A C; Mayer Alegre, T P; Medeiros-Ribeiro, G

2009-07-01

In this article we evaluate the performance of an electron paramagnetic resonance (EPR) setup using a microstrip resonator (MR). The design and characterization of the resonator are described and parameters of importance to EPR and spin manipulation are examined, including cavity quality factor, filling factor, and microwave magnetic field in the sample region. Simulated microwave electric and magnetic field distributions in the resonator are also presented and compared with qualitative measurements of the field distribution obtained by a perturbation technique. Based on EPR experiments carried out with a standard marker at room temperature and a MR resonating at 8.17 GHz, the minimum detectable number of spins was found to be 5 x 10(10) spins/GHz(1/2) despite the low MR unloaded quality factor Q0=60. The functionality of the EPR setup was further evaluated at low temperature, where the spin resonance of Cr dopants present in a GaAs wafer was detected at 2.3 K. The design and characterization of a more versatile MR targeting an improved EPR sensitivity and featuring an integrated biasing circuit for the study of samples that require an electrical contact are also discussed.

Charge-partitioning study of a wide-pitch silicon micro-strip detector with a 64-channel CMOS preamplifier array

International Nuclear Information System (INIS)

Ikeda, H.; Tsuboyama, T.; Okuno, S.; Saitoh, Y.; Akamine, T.; Satoh, K.; Inoue, M.; Yamanaka, J.; Mandai, M.; Takeuchi, H.; Kitta, T.; Miyahara, S.; Kamiya, M.

1996-01-01

The wider pitch readout operation of a 50 μm-pitch double-sided silicon micro-strip detector has been studied specifically concerning its ohmic side. Every second readout and ganged configuration was examined by employing a newly developed 64-channel preamplifier array. The observed charge responses for collimated IR light were compared with a numerical model. (orig.)

A silicon microstrip detector in a magnetic spectrometer for high-resolution electron scattering experiments at the S-DALINAC

International Nuclear Information System (INIS)

Lenhardt, A.W.; Bonnes, U.; Burda, O.; Neumann-Cosel, P. von; Platz, M.; Richter, A.; Watzlawik, S.

2006-01-01

A silicon microstrip detector was developed as focal plane detector of the 169.7 deg. magic angle double-focussing spectrometer at the superconducting Darmstadt electron linear accelerator (S-DALINAC). It allows experiments with minimum ionizing electrons at data rates up to 100 kHz, utilizing the maximum resolution of the spectrometer achievable in dispersion-matching mode

Cosmic Microwave Background Polarization Detector with High Efficiency, Broad Bandwidth, and Highly Symmetric Coupling to Transition Edge Sensor Bolometers

Science.gov (United States)

Wollack, E.; Cao, N.; Chuss, D.; Denis, K.; Hsieh, W.-T.; Moseley, S. Harvey; Schneider, G.; Stevenson, T.; Travers, D.; U-yen, K.

2008-01-01

Four probe antennas transfer signals from waveguide to microstrip lines. The probes not only provide broadband impedance matching, but also thermally isolate waveguide and detector. In addition, we developed a new photonic waveguide choke joint design, with four-fold symmetry, to suppress power leakage at the interface. We have developed facilities to test superconducting circuit elements using a cryogenic microwave probe station, and more complete systems in waveguide. We used the ring resonator shown below to measure a dielectric loss tangent 99% coupling efficiency over 30% fractional bandwidth.

Towards Gotthard-II: development of a silicon microstrip detector for the European X-ray Free-Electron Laser

Science.gov (United States)

Zhang, J.; Andrä, M.; Barten, R.; Bergamaschi, A.; Brückner, M.; Dinapoli, R.; Fröjdh, E.; Greiffenberg, D.; Lopez-Cuenca, C.; Mezza, D.; Mozzanica, A.; Ramilli, M.; Redford, S.; Ruat, M.; Ruder, C.; Schmitt, B.; Shi, X.; Thattil, D.; Tinti, G.; Turcato, M.; Vetter, S.

2018-01-01

Gotthard-II is a 1-D microstrip detector specifically developed for the European X-ray Free-Electron Laser. It will not only be used in energy dispersive experiments but also as a beam diagnostic tool with additional logic to generate veto signals for the other 2-D detectors. Gotthard-II makes use of a silicon microstrip sensor with a pitch of either 50 μm or 25 μm and with 1280 or 2560 channels wire-bonded to adaptive gain switching readout chips. Built-in analog-to-digital converters and digital memories will be implemented in the readout chip for a continuous conversion and storage of frames for all bunches in the bunch train. The performance of analogue front-end prototypes of Gotthard has been investigated in this work. The results in terms of noise, conversion gain, dynamic range, obtained by means of infrared laser and X-rays, will be shown. In particular, the effects of the strip-to-strip coupling are studied in detail and it is found that the reduction of the coupling effects is one of the key factors for the development of the analogue front-end of Gotthard-II.

Design and development of a vertex reconstruction for the CMS (Compact Muon Solenoid) data. Study of gaseous and silicon micro-strips detectors (MSGC)

International Nuclear Information System (INIS)

Moreau, St.

2002-12-01

The work presented in this thesis has contributed to the development of the Compact Muon Solenoid detector (CMS) that will be installed at the future Large Hadron Collider (LHC) which will start running in summer 2007. This report is organised in three parts: the study of gaseous detectors and silicon micro-strips detectors, and a development of a software for the reconstruction and analysis of CMS data in the framework of ORCA. First, the micro-strips gaseous detectors (MSGC) study was on the ultimate critical irradiation test before their substitution in the CMS tracker. This test showed a really small number of lost anodes and a stable signal to noise ratio. This test proved that the described MSGC fulfill all the requirements to be integrated in the CMS tracker. The following contribution described a study of silicon micro-strips detectors and its electronics exposed to a 40 MHz bunched LHC like beam. These tests indicated a good behaviour of the data acquisition and control system. The signal to noise ratio, the bunch crossing identification and the cluster finding efficiency had also be analysed. The last study concern the design and the development of an ORCA algorithm dedicates to secondary vertex reconstruction. This iterative algorithm aims to be use for b tagging. This part analyse also primary vertex reconstruction in events without and with pile up. (author)

Integrated polarization beam splitter with relaxed fabrication tolerances

OpenAIRE

Perez-Galacho, D.; Halir, R.; Ortega-Monux, A.; Alonso-Ramos, C.; Zhang, R.; Runge, P.; Janiak, K.; Bach, H-G; Steffan, A. G.; Molina-Fernandez, I.

2013-01-01

Polarization handling is a key requirement for the next generation of photonic integrated circuits (PICs). Integrated polarization beam splitters (PBS) are central elements for polarization management, but their use in PICs is hindered by poor fabrication tolerances. In this work we present a fully passive, highly fabrication tolerant polarization beam splitter, based on an asymmetrical Mach-Zehnder interferometer (MZI) with a Si/SiO2 Periodic Layer Structure (PLS) on top of one of its arms. ...

Nuclear reactivity control using laser induced polarization

International Nuclear Information System (INIS)

Bowman, C.D.

1990-01-01

This patent describes a control element for reactivity control of a fission source provides an atomic density of 3 He in a control volume which is effective to control criticality as the 3 He is spin-polarized. Spin-polarization of the 3 He affects the cross section of the control volume for fission neutrons and hence, the reactivity. An irradiation source is directed within the 3 He for spin-polarizing the 3 He. An alkali-metal vapor may be included with the 3 He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with 3 He to spin-polarize the 3 He atoms

The S-DALINAC polarized electron injector SPIN

Energy Technology Data Exchange (ETDEWEB)

Eckardt, Christian; Bahlo, Thore; Bangert, Phillip; Barday, Roman; Bonnes, Uwe; Brunken, Marco; Burandt, Christoph; Eichhorn, Ralf; Enders, Joachim; Espig, Martin; Platz, Markus; Poltoratska, Yuliya; Roth, Markus; Schneider, Fabian; Wagner, Markus; Weber, Antje; Zwicker, Benjamin [Institut fuer Kernphysik, Technische Universitaet, Darmstadt (Germany); Ackermann, Wolfgang; Mueller, Wolfgang F.O.; Weiland, Thomas [Institut fuer Theorie Elektromagnetischer Felder, Technische Universitaet, Darmstadt (Germany); Aulenbacher, Kurt [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, Mainz (Germany)

2011-07-01

A source of polarized electrons has been installed at the superconducting 130 MeV Darmstadt electron linac S-DALINAC. Polarized electrons are generated by irradiating a GaAs cathode with pulsed Ti:Sapphire and diode lasers and preaccelerated to 100 keV. A Wien filter and 100 keV Mott polarimeter are used for spin manipulation and polarization measurement and various beam diagnostic elements are installed. To measure the beam polarization downstream of the superconducting injector linac a 5-10 MeV Mott polarimeter and a Compton-transmission polarimeter have been developed. We report on the status of the polarized electron source and foreseen experiments.

Breakdown of coupling dielectrics for Si microstrip detectors

International Nuclear Information System (INIS)

Candelori, A.; Paccagnella, A.; Padova Univ.; Saglimbeni, G.

1999-01-01

Double-layer coupling dielectrics for AC-coupled Si microstrip detectors have been electrically characterized in order to determine their performance in a radiation-harsh environment, with a focus on the dielectric breakdown. Two different dielectric technologies have been investigated: SiO 2 /TEOS and SiO 2 /Si 3 N 4 . Dielectrics have been tested by using a negative gate voltage ramp of 0.2 MV/(cm·s). The metal/insulator/Si I-V characteristics show different behaviours depending on the technology. The extrapolated values of the breakdown field for unirradiated devices are significantly higher for SiO 2 /Si 3 N 4 dielectrics, but the data dispersion is lower for SiO 2 /TEOS devices. No significant variation of the breakdown field has been measured after a 10 Mrad (Si) γ irradiation for SiO 2 /Si 3 N 4 dielectrics. Finally, the SiO 2 /Si 3 N 4 DC conduction is enhanced if a positive gate voltage ramp is applied with respect to the negative one, due to the asymmetric conduction of the double-layer dielectric

A Quarter Ellipse Microstrip Resonator for Filters in Microwave Frequencies

Directory of Open Access Journals (Sweden)

Samuel Á. Jaramillo-Flórez

2013-11-01

Full Text Available This work describes the results of computational simulations and construction of quadrant elliptical resonators excited by coplanar slot line waveguide for designing microwave filters in RF communications systems. By means of the equation of optics, are explained the fundamentals of these geometry of resonators proposed. Are described the construction of quadrant elliptical resonators, one of microstrip and other two of cavity, of size different, and an array of four quadrant elliptical resonators in cascade. The results of the measures and the computational calculus of scattering S11 and S21 of elliptical resonators is made for to identify the resonant frequencies of the resonators studied, proving that these have performance in frequency as complete ellipses by the image effect due to their two mirror in both semiaxis, occupying less area, and the possible applications are discussed.

"Diamond" over-coated Microstrip Gas Chambers for high rate operation

CERN Document Server

Barr, A J; Bouclier, Roger; Capéans-Garrido, M; Dominik, Wojciech; Hoch, M; Manzin, G; Million, Gilbert; Ropelewski, Leszek; Sauli, Fabio; Sharma, A

1997-01-01

We describe the recent developments on the diamond-like carbon (DLC) over-coated Microstrip Gas Chambers made on drawn glass substrates. MSGC surface coating with thin DLC layer of stable and controlled resistivity was proposed to overcome the limitation of detector operation due to surface charging-up under avalanches. This brings also advantages for the detector manufacturing technology. The thin layer, deposited on top of a manufactured MSGC (over-coating), demonstrates excellent mechanical properties and very good stability. We report on recent measurements with DLC over-coated MSGCs of various surface resistivities (ranging from 1013W/r to 1016W/r) on D-263 and AF45 glass substrates. Over-coated MSGCs exhibit good rate capability for the resistivity of the surface around 1015W/r. Stable operation up to 50 mC/cm of accumulated charge from avalanches has been demonstrated.

Operation of sealed microstrip gas chambers at the ILL

CERN Document Server

Clergeau, J F; Feltin, D; Fischer, H E; Guérard, B; Hansen, T; Manzin, G; Oed, A; Palleau, P

2001-01-01

Microstrip Gas Counters (MSGCs) were introduced at the ILL as a response to the problem of fabricating the large area neutron detector of the D20 neutron powder diffractometer. This banana-like detector consists of 48 MSGCs, each comprising 32 counting cells. It was in operation during 18 months before being stopped due to the progressive deterioration of the anode strips. In order to increase its lifetime, significant modifications were introduced in the recently assembled new version. Another instrument, D4C, was recently equipped with a modular detector made of nine MSGCs, each of them in an individual gas vessel. Besides the unidimensional individual readout MSGC of D20 and D4C, the ILL has developed bidimensional MSGCs with a charge division readout. All these detectors employ sealed vessels containing a gas mixture at a pressure which can be as high as 15 bar, necessitating very clean conditions. This paper describes the experience acquired at the ILL in the fabrication and operation of these detectors.

Polarized excitons and optical activity in single-wall carbon nanotubes

Science.gov (United States)

Chang, Yao-Wen; Jin, Bih-Yaw

2018-05-01

The polarized excitons and optical activity of single-wall carbon nanotubes (SWNTs) are studied theoretically by π -electron Hamiltonian and helical-rotational symmetry. By taking advantage of the symmetrization, the single-particle energy and properties of a SWNT are characterized with the corresponding helical band structure. The dipole-moment matrix elements, magnetic-moment matrix elements, and the selection rules can also be derived. Based on different selection rules, the optical transitions can be assigned as the parallel-polarized, left-handed circularly-polarized, and right-handed circularly-polarized transitions, where the combination of the last two gives the cross-polarized transition. The absorption and circular dichroism (CD) spectra are simulated by exciton calculation. The calculated results are well comparable with the reported measurements. Built on the foundation, magnetic-field effects on the polarized excitons and optical activity of SWNTs are studied. Dark-bright exciton splitting and interband Faraday effect in the CD spectrum of SWNTs under an axial magnetic field are predicted. The Faraday rotation dispersion can be analyzed according to the selection rules of circular polarizations and the helical band structure.

General formulae for polarization observables in deuteron electrodisintegration and linear relations

International Nuclear Information System (INIS)

Arenhoevel, H.; Leidemann, W.; Tomusiak, E.L.

1993-01-01

Formal expressions are derived for all possible polarization observables in deuteron electrodisintegration with longitudinally polarized incoming electrons, oriented deuteron targets and polarization analysis of outgoing nucleons. They are given in terms of general structure functions which can be determined experimentally. These structure functions are Hermitean forms of the T-matrix elements which, in principle, allow the determination of all T-matrix elements up to an arbitrary common phase. Since the set of structure functions is overcomplete, linear relations among various structure functions exist which are derived explicitly

Multiband Bandstop Filter using an I-Stub-Loaded Meandered Defected Microstrip Structure

Directory of Open Access Journals (Sweden)

G. R. Koirala

2016-04-01

Full Text Available This paper presents a compact multiband bandstop filter (BSF that utilizes an I-stub embedded within a meandered defected microstrip structure (MDMS. The proposed design for obtaining a single stopband is analyzed by using a transmission line network model. On the basis of the single stopband structure, we designed and fabricated a dual- and tri-band bandstop filters operating at 2.5/6.78 GHz and 1.98/5.60/7.78 GHz, respectively, thereby exploring the concept of generating as many stopbands by simply adding the same number of I-stubs. The proposed filter also features the possibility of tuning the resonant frequencies by varying the width of the I-stubs.

High rate operation of micro-strip gas chambers on diamond-coated glass

CERN Document Server

Bouclier, Roger; Million, Gilbert; Ropelewski, Leszek; Sauli, Fabio; Temmel, T; Cooke, R A; Donnel, S; Sastri, S A; Sonderer, N

1996-01-01

Very high rate operation of micro­strip gas chambers can be achieved using slightly conducting substrates. We describe preliminary measurements realized with detectors manufactured on boro-silicate glass coated, before the photo-lithographic processing, with a diamond layer having a surface resistivity of around 1014 ‡/o. Stable medium-term operation, and a rate capability largely exceeding the one obtained with identical plates manufactured on uncoated glass are demonstrated. If these results are confirmed by long-term measurements the diamond coating technology appears very attractive since it allows, with a moderate cost overhead, to use thin, commercially available glass with the required surface quality for the large-scale production of gas micro-strip detectors.

Leakage current-induced effects in the silicon microstrip and gas electron multiplier readout chain and their compensation method

Science.gov (United States)

Zubrzycka, W.; Kasinski, K.

2018-04-01

Leakage current flowing into the charge sensitive amplifier (CSA) is a common issue in many radiation detection systems as it can increase overall system noise, shift a DC baseline or even lead a recording channel to instability. The commonly known leakage current contributor is a detector, however other system components like wires or an input protection circuit may become a serious problem. Compensation of the leakage current resulting from the electrostatic discharge (ESD) protection circuit by properly sizing its components is possible only for a narrow temperature range. Moreover, the leakage current from external sources can be significantly larger. Many applications, especially High Energy Physics (HEP) experiments, require a fast baseline restoration for high input hit rates by applying either a low-value feedback resistor or a high feedback resistance combined with a pulsed reset circuit. Leakage current flowing in the feedback in conjunction with a large feedback resistance supplied with a pulsed reset results in a significant voltage offset between the CSA input and output which can cause problems (e.g. fake hits or instability). This paper shows an issue referred to the leakage current of the ESD protection circuit flowing into the input amplifier. The following analysis and proposed solution is a result of the time and energy readout ASIC project realization for the Compressed Baryonic Matter (CBM) experiment at FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. This chip is purposed to work with microstrip and gaseous detectors, with high average input pulses frequencies (250 kHit/s per channel) and the possibility to process input charge of both polarities. We present measurements of the test structure fabricated in UMC 180 nm technology and propose a solution addressing leakage current related issues. This work combines the leakage current compensation capabilities at the CSA level with high, controllable value of the amplifier

Apodised aperture using rotation of plane of polarization

International Nuclear Information System (INIS)

Simmons, W.W.; Leppelmeier, G.W.; Johnson, B.C.

1975-01-01

An apodised aperture based on the rotation of plane of polarization producing desirable characteristics on a transmitted light beam such as beam profiling in high flux laser amplifier chains is described. The apodised aperture is made with a lossless element by using one or more polarizers and/or analyzers and magneto-optical Faraday means for selectively rotating the plane of polarized radiation over the cross section to effect the desired apodisation

A Thick Film Microstrip Butler Matrix for the Frequency Range 1.5-1.7 GHz.

Science.gov (United States)

1979-09-01

The 1800 hybrid coupler II 4.1.5 The broadside coupler 11 4.1.6 The Podell coupler 12 4.2 Phase shifters 12 4.2.1 The dielectrically loaded line phase...The Podell coupler The Podell coupler8 of Fig 9b overcomes even and odd mode velocity disper- sion by using a sawtooth design on the inner edge. This...8 A. Podell A high directivity microstrip coupler technique. IEEE G-MTT International Microwave Symposium, 33-36 (1970) 9 B. Easter The equivalent

Metasurface Reflector (MSR Loading for High Performance Small Microstrip Antenna Design.

Directory of Open Access Journals (Sweden)

Md Rezwanul Ahsan

Full Text Available A meander stripline feed multiband microstrip antenna loaded with metasurface reflector (MSR structure has been designed, analyzed and constructed that offers the wireless communication services for UHF/microwave RFID and WLAN/WiMAX applications. The proposed MSR assimilated antenna comprises planar straight forward design of circular shaped radiator with horizontal slots on it and 2D metasurface formed by the periodic square metallic element that resembles the behavior of metamaterials. A custom made high dielectric bio-plastic substrate (εr = 15 is used for fabricating the prototype of the MSR embedded planar monopole antenna. The details of the design progress through numerical simulations and experimental results are presented and discussed accordingly. The measured impedance bandwidth, radiation patterns and gain of the proposed MSR integrated antenna are compared with the obtained results from numerical simulation, and a good compliance can be observed between them. The investigation shows that utilization of MSR structure has significantly broadened the -10 dB impedance bandwidth than the conventional patch antenna: from 540 to 632 MHz (17%, 467 to 606 MHz (29% and 758 MHz to 1062 MHz (40% for three distinct operating bands centered at 0.9, 3.5 and 5.5 GHz. Additionally, due to the assimilation of MSR, the overall realized gains have been upgraded to a higher value of 3.62 dBi, 6.09 dBi and 8.6 dBi for lower, middle and upper frequency band respectively. The measured radiation patterns, impedance bandwidths (S11<-10 dB and gains from the MSR loaded antenna prototype exhibit reasonable characteristics that can satisfy the requirements of UHF/microwave (5.8 GHz RFID, WiMAX (3.5/5.5 GHz and WLAN (5.2/5.8 GHz applications.

The 40x40cm2 gaseous microstrip detector Micromegas for the high-luminosity COMPASS experiment at CERN

International Nuclear Information System (INIS)

Bernet, C.; Abbon, P.; Ball, J.; Bedfer, Y.; Delagnes, E.; Giganon, A.; Kunne, F.; Le Goff, J.-M.; Magnon, A.; Marchand, C.; Neyret, D.; Panebianco, S.; Pereira, H.; Platchkov, S.; Procureur, S.; Rebourgeard, P.; Tarte, G.; Thers, D.

2005-01-01

The measurements in the COMPASS experiment at CERN require high-resolution tracking detectors, with low radiation length and high-rate capability. For this purpose we have developed and optimized a gaseous microstrip detector 'Micromegas'. Twelve planes with 1024 strips each, assembled in 3 stations of 4 views XYUV, are now being operated with success in the COMPASS environment. We describe here the performances and results obtained

Design and Development of Compact Microstrip Patch Antenna for Wireless Applications

Directory of Open Access Journals (Sweden)

R. Nagendra

2017-09-01

Full Text Available In this paper, a novel dual band microstrip patch antenna based on composite patch antenna and radiating part. By selecting a suitable offset feed position, it is feasible to provide 50Ω characteristic impedance and thus making better impedance matching. The proposed antenna has been improved broader bandwidth by using RT Duroid substrate. The radiating part is plays a important role in creating a lower operating band (2.45 GHz in addition to achieve miniaturization. The proposed antenna has to be fabricated with RT / Duroid substrate and dimensions of 19 × 22 × 0.8 mm. The measured -10 dB bandwidth of 200 MHz at 2.45 GHz and 990 MHz at 5.45 GHz, which is quite useful for Industrial, Scientific and Medical (ISM and WLAN applications.

Sensing element for detection of polar organic vapours on the base of polyaniline-composite - Effect of substrate surface area

International Nuclear Information System (INIS)

Olejnik, Robert; Babar, Dipak Gorakh; Slobodian, Petr; Matyas, Jiri

2016-01-01

Conductive polymer polyaniline (PANI) was synthesized by oxidative polymerization of aniline hydrochloride as a source of aniline and ammonium persulfate as an oxidation agent. The polymerization process is relatively easy and cheap. The reaction was carried out in presence of polymer substrate, in our case polyethylene terephthalate (PET) as a representative of smooth surface substrate and polyvinylidenfluoride (PVDF) nanofibers membrane as a representative of porous substrate. Both these substrates were covered by polyaniline (PANI) and used as a sensing element for organic vapors detection. The detection was made by measuring and the record of the change of resistivity during adsorption and desorption of saturated vapors. The result shows that sensitivity decreases with increasing polarity of chosen solvent in order N,N- Dimethylformamide (DMF), N,N-Dimethylacetamide (DMAc) and Dimethyl sulfoxide (DMSO). The PANI base sensing element on PVDF substrate improves sensitivity, selectivity and it also has good reversibility and repeatability. (paper)

Restoring in-phase emissions from non-planar radiating elements using a transformation optics based lens

International Nuclear Information System (INIS)

Yi, Jianjia; Burokur, Shah Nawaz; Lustrac, André de; Piau, Gérard-Pascal

2015-01-01

The broadband directive in-phase emission from an array of sources conformed cylindrically is numerically and experimentally reported. Such manipulation is achieved through the use of a lens designed by transformation optics concept. The all-dielectric lens prototype is realized through three-dimensional (3D) polyjet printing and presents a graded refractive index. A microstrip antenna array fabricated using standard lithography techniques and conformed on a cylindrical surface is used as TE-polarized wave launcher for the lens. To experimentally demonstrate the broadband focusing properties and in-phase directive emissions, both the far-field radiation patterns and the near-field distributions have been measured. Experimental measurements agreeing qualitatively with numerical simulations validate the proposed lens and open the way to inexpensive all-dielectric microwave lenses for beam forming and collimation

Restoring in-phase emissions from non-planar radiating elements using a transformation optics based lens

Energy Technology Data Exchange (ETDEWEB)

Yi, Jianjia [IEF, CNRS, UMR 8622, Université Paris-Sud, 91405 Orsay Cedex (France); Burokur, Shah Nawaz, E-mail: shah-nawaz.burokur@u-psud.fr; Lustrac, André de [IEF, CNRS, UMR 8622, Université Paris-Sud, 91405 Orsay Cedex (France); Université Paris-Ouest, 92410 Ville d' Avray (France); Piau, Gérard-Pascal [AIRBUS Group Innovations, 92150 Suresnes (France)

2015-07-13

The broadband directive in-phase emission from an array of sources conformed cylindrically is numerically and experimentally reported. Such manipulation is achieved through the use of a lens designed by transformation optics concept. The all-dielectric lens prototype is realized through three-dimensional (3D) polyjet printing and presents a graded refractive index. A microstrip antenna array fabricated using standard lithography techniques and conformed on a cylindrical surface is used as TE-polarized wave launcher for the lens. To experimentally demonstrate the broadband focusing properties and in-phase directive emissions, both the far-field radiation patterns and the near-field distributions have been measured. Experimental measurements agreeing qualitatively with numerical simulations validate the proposed lens and open the way to inexpensive all-dielectric microwave lenses for beam forming and collimation.

Personal history of nucleon polarization experiments

International Nuclear Information System (INIS)

Chamberlain, O.

1984-09-01

The history of nucleon scattering experiments is reviewed, starting with the observation of large proton polarizations in scattering from light elements such as carbon, and ending with the acceleration of polarized proton beams in high-energy synchrotrons. Special mention is made about significant contributions made by C.L. Oxley, L. Wolfenstein, R.D. Tripp, T. Ypsilantis, A. Abragam, M. Borghini, T. Niinikoski, Froissart, Stora, A.D. Krisch, and L.G. Ratner

Photon counting microstrip X-ray detectors with GaAs sensors

Science.gov (United States)

Ruat, M.; Andrä, M.; Bergamaschi, A.; Barten, R.; Brückner, M.; Dinapoli, R.; Fröjdh, E.; Greiffenberg, D.; Lopez-Cuenca, C.; Lozinskaya, A. D.; Mezza, D.; Mozzanica, A.; Novikov, V. A.; Ramilli, M.; Redford, S.; Ruder, C.; Schmitt, B.; Shi, X.; Thattil, D.; Tinti, G.; Tolbanov, O. P.; Tyazhev, A.; Vetter, S.; Zarubin, A. N.; Zhang, J.

2018-01-01

High-Z sensors are increasingly used to overcome the poor efficiency of Si sensors above 15 keV, and further extend the energy range of synchrotron and FEL experiments. Detector-grade GaAs sensors of 500 μm thickness offer 98% absorption efficiency at 30 keV and 50% at 50 keV . In this work we assess the usability of GaAs sensors in combination with the MYTHEN photon-counting microstrip readout chip developed at PSI. Different strip length and pitch are compared, and the detector performance is evaluated in regard of the sensor material properties. Despite increased leakage current and noise, photon-counting strips mounted with GaAs sensors can be used with photons of energy as low as 5 keV, and exhibit excellent linearity with energy. The charge sharing is doubled as compared to silicon strips, due to the high diffusion coefficient of electrons in GaAs.

Rapid X-ray crystal structure analysis in few second measurements using microstrip gas chamber

CERN Document Server

Ochi, A; Tanimori, T; Ohashi, Y; Toyokawa, H; Nishi, Y; Nishi, Y; Nagayoshi, T; Koishi, S

2001-01-01

X-ray crystal structure analysis using microstrip gas chamber was successfully carried out in a measurement time within a few seconds. The continuous rotation photograph method, in which most of the diffraction peaks can be obtained within one continuous rotation of the sample crystal (without stopping or oscillation), was applied for this measurement. As an example, the structure of a single crystal of ammonium bitartrate (r=1 mm, spherical) was measured. Diffraction spots from the sample, which were sufficient to obtain crystal structure, were successfully obtained by taking only 2 s measurements with a commercially available laboratory X-ray source.

FILTRES: a 128 channels VLSI mixed front-end readout electronic development for microstrip detectors

International Nuclear Information System (INIS)

Anstotz, F.; Hu, Y.; Michel, J.; Sohler, J.L.; Lachartre, D.

1998-01-01

We present a VLSI digital-analog readout electronic chain for silicon microstrip detectors. The characteristics of this circuit have been optimized for the high resolution tracker of the CERN CMS experiment. This chip consists of 128 channels at 50 μm pitch. Each channel is composed by a charge amplifier, a CR-RC shaper, an analog memory, an analog processor, an output FIFO read out serially by a multiplexer. This chip has been processed in the radiation hard technology DMILL. This paper describes the architecture of the circuit and presents test results of the 128 channel full chain chip. (orig.)

An offset-fed 20/30 GHz dual-band circularly polarized reflectarray antenna

DEFF Research Database (Denmark)

Smith, Thomas Gunst; Vesterdal, Niels; Gothelf, Ulrich

2013-01-01

A dual-frequency circularly polarized offset reflectarray antenna for Ka-band satellite communication is presented. The reflectarray is designed using the concentric dual split-loop element which enables full 360° phase adjustment simultaneously in two separate frequency bands. The elements have...... been optimized to suppress the cross-polar reflection. Thereafter, the element data is used for synthesis of the reflectarray layout and computation of the associated radiation patterns. The reflectarray is 400mm × 400mm and radiates LHCP at 19.95 GHz and RHCP at 29.75 GHz. Aperture efficiencies of 58......% and 60% are obtained at these frequencies, and the cross-polarization is more than 25 dB below peak gain....

Mechanical studies towards a silicon micro-strip super module for the ATLAS inner detector upgrade at the high luminosity LHC

International Nuclear Information System (INIS)

Barbier, G; Cadoux, F; Clark, A; Favre, Y; Ferrere, D; Gonzalez-Sevilla, S; Iacobucci, G; Marra, D La; Perrin, E; Seez, W; Endo, M; Hanagaki, K; Hara, K; Ikegami, Y; Nakamura, K; Takubo, Y; Terada, S; Jinnouchi, O; Nishimura, R; Takashima, R

2014-01-01

It is expected that after several years of data-taking, the Large Hadron Collider (LHC) physics programme will be extended to the so-called High-Luminosity LHC, where the instantaneous luminosity will be increased up to 5 × 10 34  cm −2  s −1 . For the general-purpose ATLAS experiment at the LHC, a complete replacement of its internal tracking detector will be necessary, as the existing detector will not provide the required performance due to the cumulated radiation damage and the increase in the detector occupancy. The baseline layout for the new ATLAS tracker is an all-silicon-based detector, with pixel sensors in the inner layers and silicon micro-strip detectors at intermediate and outer radii. The super-module (SM) is an integration concept proposed for the barrel strip region of the future ATLAS tracker, where double-sided stereo silicon micro-strip modules (DSM) are assembled into a low-mass local support (LS) structure. Mechanical aspects of the proposed LS structure are described

Building blocks for a polarimeter-on-a-chip

International Nuclear Information System (INIS)

Stevenson, Thomas R.; Hsieh, W.-T.; Schneider, Gideon; Travers, Douglas; Cao, Nga; Wollack, Edward; Limon, Michele; Kogut, Alan

2006-01-01

For the 'Primordial Anisotropy Polarization Pathfinder Array (PAPPA)' balloon flight project, we have designed and made thin-film niobium microstrip circuits as building blocks for a 'polarimeter-on-a-chip' in which superconducting transmission lines are used to couple millimeter wave signals from planar antennas to superconducting transition edge sensor (TES) detectors. Our goal is to demonstrate technology for precision measurements of the polarization of the cosmic microwave background. To enable characterization and verification of our microstrip components, we have incorporated waveguide probes on each chip that can bring millimeter wave signals from a room temperature vector network analyzer to the superconducting circuits on the chip and back again for S-parameter measurements. We have designed a planar antenna and RF choke on the probes to efficiently couple radiation between waveguide and thin-film microstrip. To support the probe antennas in waveguides, we sculpted thin silicon cantilevers that extend from an edge of each silicon chip into a pair of waveguides within a specially designed split-block mount. This technique will allow us to make calibrated measurements at low temperatures of the velocity, impedance, and loss properties of our niobium transmission lines, the frequency response of microstrip filters, hybrid couplers, or terminations, and the performance of integrated detectors

Semiconductor sensor for optically measuring polarization rotation of optical wavefronts using rare earth iron garnets

Science.gov (United States)

Duncan, Paul G.

2002-01-01

Described are the design of a rare earth iron garnet sensor element, optical methods of interrogating the sensor element, methods of coupling the optical sensor element to a waveguide, and an optical and electrical processing system for monitoring the polarization rotation of a linearly polarized wavefront undergoing external modulation due to magnetic field or electrical current fluctuation. The sensor element uses the Faraday effect, an intrinsic property of certain rare-earth iron garnet materials, to rotate the polarization state of light in the presence of a magnetic field. The sensor element may be coated with a thin-film mirror to effectively double the optical path length, providing twice the sensitivity for a given field strength or temperature change. A semiconductor sensor system using a rare earth iron garnet sensor element is described.

Polarization-controlled asymmetric excitation of surface plasmons

KAUST Repository

Xu, Quan

2017-08-28

Free-space light can be coupled into propagating surface waves at a metal–dielectric interface, known as surface plasmons (SPs). This process has traditionally faced challenges in preserving the incident polarization information and controlling the directionality of the excited SPs. The recently reported polarization-controlled asymmetric excitation of SPs in metasurfaces has attracted much attention for its promise in developing innovative plasmonic devices. However, the unit elements in these works were purposely designed in certain orthogonal polarizations, i.e., linear or circular polarizations, resulting in limited two-level polarization controllability. Here, we introduce a coupled-mode theory to overcome this limit. We demonstrated theoretically and experimentally that, by utilizing the coupling effect between a pair of split-ring-shaped slit resonators, exotic asymmetric excitation of SPs can be obtained under the x-, y-, left-handed circular, and right-handed circular polarization incidences, while the polarization information of the incident light can be preserved in the excited SPs. The versatility of the presented design scheme would offer opportunities for polarization sensing and polarization-controlled plasmonic devices.

Dual-Band Split-Ring Antenna Design for WLAN Applications

OpenAIRE

BAŞARAN, S. Cumhur; ERDEMLİ, Yunus E.

2014-01-01

A dual-band microstrip antenna based on split-ring elements is introduced for WLAN (2.4/5.2 GHz) applications. The proposed split-ring antenna (SRA) has a compact novel design which provides about 2% impedance-bandwidth without a need for additional matching network. Analysis and design of the proposed microstrip antenna is carried out by means of full-wave simulators based on the finite-element method.

Development of a Test System for the Quality Assurance of Silicon Microstrip Detectors for the Inner Tracking System of the CMS Experiment

CERN Document Server

Axer, Markus

2003-01-01

The inner tracking system of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) which is being built at the European Laboratory for Particle Physics CERN (Geneva, Switzerland) will be equipped with two different technologies of silicon detectors. While the innermost tracker will be composed of silicon pixel detectors, silicon microstrip detectors are envisaged for the outer tracker architecture. The silicon microstrip tracker will house about 15,000 single detector modules each composed of a set of silicon sensors, the readout electronics (front end hybrid), and a support frame. It will provide a total active area of 198 m2 and ten million analogue channels read out at the collider frequency of 40 MHz. This large number of modules to be produced and integrated into the tracking system is an unprecedented challenge involving industrial companies and various research institutes from many different countries. This thesis deals with the physics of silicon sensors and the preparation of ...

Towards long lived tunable transmon qubit in microstrip geometry

Energy Technology Data Exchange (ETDEWEB)

Braumueller, Jochen; Radtke, Lucas; Rotzinger, Hannes; Weides, Martin; Ustinov, Alexey V. [Karlsruhe Institute of Technology (KIT), Physikalisches Institut, 76131 Karlsruhe (Germany)

2013-07-01

Qubits constitute the main building blocks of a prospective quantum computer. One main challenge is given by short decoherence times. In this work we investigate a transmon qubit based on a superconducting charge qubit with reduced sensitivity to charge noise. This is achieved by operating the qubit at a Josephson to charging energy ratio of about 100. At the same time, a sufficiently large anharmonicity of the energy levels is preserved. The qubit is realized in a 2D geometry based on large capacitor pads being connected by two Josephson junctions in parallel. This split Josephson junction allows the qubit to be tunable in Josephson energy and therefore in resonance frequency. The large area capacitor pads mainly coupled through the substrate and a backside metalization reduce the surface loss contribution. Manipulation and readout of the qubit is mediated by a microstrip resonator coupled to a feedline. We present resonator and qubit designs together with respective microwave simulations. Preliminary results on circuit fabrication and low temperature measurements are also discussed.

A Small Ku-Band Polarization Tracking Active Phased Array for Mobile Satellite Communications

Directory of Open Access Journals (Sweden)

Wei Shi

2013-01-01

Full Text Available A compact polarization tracking active phased array for Ku-band mobile satellite signal reception is presented. In contrast with conventional mechanically tracking antennas, the approach presented here meets the requirements of beam tracking and polarization tracking simultaneously without any servo components. The two-layer stacked square patch fed by two probes is used as antenna element. The impedance bandwidth of 16% for the element covers the operating frequency range from 12.25 GHz to 12.75 GHz. In the presence of mutual coupling, the dimensional parameters for each element of the small 7 × 7 array are optimized during beam scanning and polarization tracking. The compact polarization tracking modules based on the low-temperature cofired ceramic (LTCC system-in-package (SiP technology are proposed. A small active phased array prototype with the size of 120 mm (length × 120 mm (width × 55 mm (height is developed. The measured polarization tracking patterns of the prototype are given. The polarization tracking beam can be steered in the elevation up to 50°. The gain of no less than 16.0 dBi and the aperture efficiency of more than 50% are obtained. The measured and simulated polarization tracking patterns agreed well.

Stroke Diagnosis using Microstrip Patch Antennas Based on Microwave Tomography Systems

Directory of Open Access Journals (Sweden)

Sakthisudhan K

2017-03-01

Full Text Available Microwave tomography (MT based on stroke diagnosis is one of the alternative methods for determinations of the haemorrhagic, ischemic and stroke in brain nervous systems. It is focusing on the brain imaging, continuous monitoring, and preclinical applications. It provides cost effective system and able to use the rural and urban medical clinics that lack the necessary resources in effective stroke diagnosis during emerging applications in road accident and pre-ambulance clinical treatment. In the early works, the design of microstrip patch antennas (MPAs involved the implementation of MT system. Consequently, the MT system presented a few limitations since it required an efficient MPA design with appropriate parameters. Moreover, there were no specific diagnosis modules and body centric features in it. The present research proposes the MPA designs in the forms of diagnosis modules and implements it on the MT system.

Microstrip electrode readout noise for load-dominated long shaping-time systems

International Nuclear Information System (INIS)

Collier, Kelsey; Cunnington, Taylor; Crosby, Sean; Fadeyev, Vitaliy; Martinez-McKinney, Forest; Mistry, Khilesh; Schumm, Bruce A.; Spencer, Edwin; Taylor, Aaron; Wilder, Max

2013-01-01

In cases such as that of the proposed International Linear Collider (ILC), for which the beam-delivery and detector-occupancy characteristics permit a long shaping-time readout of the microstrip sensors, it is possible to envision long (∼1 meter) daisy-chained ‘ladders’ of fine-pitch sensors read out by a single front-end amplifier. In this study, a long shaping-time (∼2μsec) front-end amplifier has been used to measure readout noise as a function of detector load. Comparing measured noise to that expected from lumped and distributed models of the load network, it is seen that network effects significantly mitigate the amount of readout noise contributed by the detector load. Further reduction in noise is demonstrated for the case that the sensor load is read out from its center rather than its end

Microstrip electrode readout noise for load-dominated long shaping-time systems

Energy Technology Data Exchange (ETDEWEB)

Collier, Kelsey; Cunnington, Taylor; Crosby, Sean; Fadeyev, Vitaliy; Martinez-McKinney, Forest; Mistry, Khilesh; Schumm, Bruce A., E-mail: baschumm@ucsc.edu; Spencer, Edwin; Taylor, Aaron; Wilder, Max

2013-11-21

In cases such as that of the proposed International Linear Collider (ILC), for which the beam-delivery and detector-occupancy characteristics permit a long shaping-time readout of the microstrip sensors, it is possible to envision long (∼1 meter) daisy-chained ‘ladders’ of fine-pitch sensors read out by a single front-end amplifier. In this study, a long shaping-time (∼2μsec) front-end amplifier has been used to measure readout noise as a function of detector load. Comparing measured noise to that expected from lumped and distributed models of the load network, it is seen that network effects significantly mitigate the amount of readout noise contributed by the detector load. Further reduction in noise is demonstrated for the case that the sensor load is read out from its center rather than its end.

Matlab/Simulink Implementation of Wave-based Models for Microstrip Structures utilizing Short-circuited and Opened Stubs

Directory of Open Access Journals (Sweden)

Biljana P. Stošić

2011-12-01

Full Text Available This paper describes modeling and analyzing procedures for microstrip filters based on use of one-dimensional wave digital approach. Different filter structures are observed. One filter is based on quarter-wave length short-circuited stubs and connecting transmission lines. The other one is based on cross-junction opened stubs. Frequency responses are obtained by direct analysis of the block-based networks formed in Simulink toolbox of MATLAB environment. This wave-based method allows an accurate and efficient analysis of different microwave structures.

An improved broadband E patch microstrip antenna for wireless communications

Science.gov (United States)

Bzeih, Amer; Chahine, Soubhi Abou; Kabalan, Karim Y.; El-Hajj, Ali; Chehab, Ali

2007-12-01

A broadband probe-fed microstrip antenna with E-shaped patch on a single-layer air substrate is investigated. Bandwidth enhancement of the antenna is achieved by inserting two parallel slots into its radiating patch. The effects of the antenna parameters are analyzed, and their optimal values for broadband operation are obtained. The design parameters are formulated as a function of the center frequency, and the empirical equations are validated by simulation. A 51.5% enhanced E patch antenna for modern wireless communications (Personal Communications Service, Digital Cellular System, Universal Mobile Telecommunications System, Wireless Local Area Network 802.11 b/g, and Bluetooth) is designed, simulated, fabricated, and measured. A comparison between simulated and measured results is presented, and it showed satisfactory agreement. Moreover, the effect of incorporating more parallel slots into the radiating patch is investigated. The antenna is designed and simulated for different scenarios (four slots, six slots, and eight slots), where a bandwidth of 57% is achieved in the eight-slot design.

Study of silicon microstrips detector quantum efficiency using mathematical simulation

International Nuclear Information System (INIS)

Leyva Pernia, Diana; Cabal Rodriguez, Ana Ester; Pinnera Hernandez, Ibrahin; Fabelo, Antonio Leyva; Abreu Alfonso, Yamiel; Cruz Inclan, Carlos M.

2011-01-01

The paper shows the results from the application of mathematical simulation to study the quantum efficiency of a microstrips crystalline silicon detector, intended for medical imaging and the development of other applications such as authentication and dating of cultural heritage. The effects on the quantum efficiency of some parameters of the system, such as the detector-source geometry, X rays energy and detector dead zone thickness, were evaluated. The simulation results were compared with the theoretical prediction and experimental available data, resulting in a proper correspondence. It was concluded that the use of frontal configuration for incident energies lower than 17 keV is more efficient, however the use of the edge-on configuration for applications requiring the detection of energy above this value is recommended. It was also found that the reduction of the detector dead zone led to a considerable increase in quantum efficiency for any energy value in the interval from 5 to 100 keV.(author)

Development and Evaluation of Test Stations for the Quality Assurance of the Silicon Micro-Strip Detector Modules for the CMS Experiment

CERN Document Server

Pöttgens, Michael

2007-01-01

CMS (Compact Muon Solenoid) is one of four large-scale detectors which will be operated at the LHC (Large Hadron Collider) at the European Laboratory for Particle Physics (CERN). For the search for new physics the reconstruction of the collision products and their properties is essential. In the innermost part of the CMS detector the traces of ionizing particles are measured utilizing a silicon tracker. A large fraction of this detector is equipped with silicon micro-strip modules which provide a precise space resolution in 1-dimension. A module consists of a sensor for detection of particles, the corresponding read-out electronics (hybrid) and a mechanical support structure. Since the 15,148 modules, which will be installed in the silicon micro-strip detector, have a total sensitive surface area of about 198 m2, the inner tracker of CMS is the largest silicon tracking detector, which has ever been built. While the sensors and hybrids are produced in industry, the construction of the modules and the control o...

Fine-Tuning on the Effective Patch Radius Expression of the Circular Microstrip Patch Antennas

Directory of Open Access Journals (Sweden)

A. E. Yilmaz

2010-09-01

Full Text Available In this study, the effective patch radius expression for the circular microstrip antennas is improved by means of several manipulations. Departing from previously proposed equations in the literature, one of the most accurate equations is picked up, and this equation is fine-tuned by means of Particle Swarm Optimization technique. Throughout the study, impacts of other parameters (such as the definition of the fitness/objective function, the degree-of-freedom in the proposed effective patch radius expression, the number of measured resonant frequency values are observed in a controlled manner. Finally, about 3% additional improvement is achieved over a very accurate formula, which was proposed earlier.

Dual-Polarized Antenna Arrays with CMOS Power Amplifiers for SiP Integration at W-Band

Science.gov (United States)

Giese, Malte; Vehring, Sönke; Böck, Georg; Jacob, Arne F.

2017-09-01

This paper presents requirements and front-end solutions for low-cost communication systems with data rates of 100 Gbit/s. Link budget analyses in different mass-market applications are conducted for that purpose. It proposes an implementation of the front-end as an active antenna array with support for beam steering and polarization multiplexing over the full W-band. The critical system components are investigated and presented. This applies to a transformer coupled power amplifier (PA) in 40 nm bulk CMOS. It shows saturated output power of more than 10 dBm and power-added-efficiency of more than 10 % over the full W-band. Furthermore, the performance of microstrip-to-waveguide transitions is shown exemplarily as an important part of the active antenna as it interfaces active circuitry and antenna in a polymer-and-metal process. The transition test design shows less than 0.9 dB insertion loss and more than 12 dB return loss for the differential transition over the full W-band.

Design, characterization and beam test performance of different silicon microstrip detector geometries

International Nuclear Information System (INIS)

Catacchini, E.; Ciampolini, L.; Civinini, C.; D'Alessandro, R.; Focardi, E.; Lenzi, M.; Meschini, M.; Parrini, G.; Pieri, M.

1998-01-01

During the last few years a large number of silicon microstrip detectors has been especially designed and tested in order to study and optimize the performances of the tracking devices to be used in the forward-backward part of the CMS (technical proposal, CERN/LHCC 94-38 LHCC/Pl, 15 December 1994) experiment. Both single and double sided silicon detectors of a trapezoidal ('wedge') shape and with different strip configurations, including prototypes produced with double metal technology, were characterized in the laboratory and tested using high-energy beams. Furthermore, due to the high-radiation environment where the detectors should operate, particular care was devoted to the study of the characteristics of heavily irradiated detectors. The main results of detector performances (charge response, signal-to-noise ratio, spatial resolution etc.) will be reviewed and discussed. (author)

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

"Printed-circuit" rectenna

Science.gov (United States)

Dickinson, R. M.

1977-01-01

Rectifying antenna is less bulky structure for absorbing transmitted microwave power and converting it into electrical current. Printed-circuit approach, using microstrip technology and circularly polarized antenna, makes polarization orientation unimportant and allows much smaller arrays for given performance. Innovation is particularly useful with proposed electric vehicles powered by beam microwaves.

Hybrid finite element/waveguide mode analysis of passive RF devices

Science.gov (United States)

McGrath, Daniel T.

1993-07-01

A numerical solution for time-harmonic electromagnetic fields in two-port passive radio frequency (RF) devices has been developed, implemented in a computer code, and validated. Vector finite elements are used to represent the fields in the device interior, and field continuity across waveguide apertures is enforced by matching the interior solution to a sum of waveguide modes. Consequently, the mesh may end at the aperture instead of extending into the waveguide. The report discusses the variational formulation and its reduction to a linear system using Galerkin's method. It describes the computer code, including its interface to commercial CAD software used for geometry generation. It presents validation results for waveguide discontinuities, coaxial transitions, and microstrip circuits. They demonstrate that the method is an effective and versatile tool for predicting the performance of passive RF devices.

A Compact Symmetric Microstrip Filter Based on a Rectangular Meandered-Line Stepped Impedance Resonator with a Triple-Band Bandstop Response

Directory of Open Access Journals (Sweden)

Rajendra Dhakal

2013-01-01

Full Text Available This paper presents a symmetric-type microstrip triple-band bandstop filter incorporating a tri-section meandered-line stepped impedance resonator (SIR. The length of each section of the meandered line is 0.16, 0.15, and 0.83 times the guided wavelength (λg, so that the filter features three stop bands at 2.59 GHz, 6.88 GHz, and 10.67 GHz, respectively. Two symmetric SIRs are employed with a microstrip transmission line to obtain wide bandwidths of 1.12, 1.34, and 0.89 GHz at the corresponding stop bands. Furthermore, an equivalent circuit model of the proposed filter is developed, and the model matches the electromagnetic simulations well. The return losses of the fabricated filter are measured to be −29.90 dB, −28.29 dB, and −26.66 dB while the insertion losses are 0.40 dB, 0.90 dB, and 1.10 dB at the respective stop bands. A drastic reduction in the size of the filter was achieved by using a simplified architecture based on a meandered-line SIR.

Polarized coincidence electroproduction

International Nuclear Information System (INIS)

Heimann, R.L.

1975-03-01

A study is made of the inclusive electroproduction of single hadrons off a polarized target. Bjorken scaling laws and the hadron azimuthal distribution are derived from the quark parton model. The polarization asymmetries scale when the target spin is along the direction of the virtual photon, and (apart from significant exception) vanish for transverse spin. These results have a simple explanation; emphasis is given both to the general mathematical formalism and to intuitive physical reasoning. Through this framework other cases are considered: quarks with anomalous magnetic moment; renormalization group effects and asymptotic freedom; production of vector mesons (whose spin state is analysed by their decay); relation to large transverse momentum hadron production; and a covariant parton model calculation. Spin 0 partons and Regge singularities are also considered. All of these cases (apart from the last two) modify the pattern of conclusions. Vector meson production shows polarization enhancements in the density matrix element rhosub(0+); the renormalization group approach does not lead to any significant suppressions. They are also less severe in parton models for large Psub(T) hadrons, and are not supported by the covariantly formulated calculation. The origins of these differences are isolated and used to exemplify the sensitivity polarized hadron electroproduction has to delicate detail that is otherwise concealed. (author)

Polarization in free electron lasers

Energy Technology Data Exchange (ETDEWEB)

Papadichev, V.A. [Lebedev Physical Institute, Moscow (Russian Federation)

1995-12-31

Polarization of electromagnetic radiation is required very often in numerous scientific and industrial applications: studying of crystals, molecules and intermolecular interaction high-temperature superconductivity, semiconductors and their transitions, polymers and liquid crystals. Using polarized radiation allows to obtain important data (otherwise inaccessible) in astrophysics, meteorology and oceanology. It is promising in chemistry and biology for selective influence on definite parts of molecules in chain synthesis reactions, precise control of various processes at cell and subcell levels, genetic engineering etc. Though polarization methods are well elaborated in optics, they can fail in far-infrared, vacuum-ultraviolet and X-ray regions because of lack of suitable non-absorbing materials and damaging of optical elements at high specific power levels. Therefore, it is of some interest to analyse polarization of untreated FEL radiation obtained with various types of undulators, with and without axial magnetic field. The polarization is studied using solutions for electron orbits in various cases: plane or helical undulator with or without axial magnetic field, two plane undulators, a combination of right- and left-handed helical undulators with equal periods, but different field amplitudes. Some examples of how a desired polarization (elliptical circular or linear) can be obtained or changed quickly, which is necessary in many experiments, are given.

Electrodynamic modeling applied to micro-strip gas chambers

International Nuclear Information System (INIS)

Fang, R.

1998-01-01

Gas gain variations as functions of time, counting rate and substrate resistivity have been observed with Micro-Strip Gas Chambers (MSGC). Such a chamber is here treated as a system of 2 dielectrics, gas and substrate, with finite resistivities. Electric charging between their interface results in variations of the electric field and the gas gain. The electrodynamic equations (including time dependence) for such a system are proposed. A Rule of Charge Accumulation (RCA) is then derived which allows to determine the quantity and sign of charges accumulated on the surface at equilibrium. In order to apply the equations and the rule to MSGCs, a model of gas conductance induced by ionizing radiation is proposed, and a differential equation and some formulae are derived to calculate the rms dispersion and the spatial distribution of electrons (ions) in inhomogeneous electric fields. RCA coupled with a precise simulation of the electric fields gives the first quantitative explanation of gas gain variations of MSGCs. Finally an electrodynamic simulation program is made to reproduce the dynamic process of gain variation due to surface charging with an uncertainty of at most 15% relative to experimental data. As a consequence, the methods for stabilizing operation of MSGCs are proposed. (author)

The study of microstrip electromagnetic properties and method of measuring {epsilon} sub r

Energy Technology Data Exchange (ETDEWEB)

Wan Ali, Wan Khairuddin [Universiti Teknologi Malaysia, Skudai, Johor Bahru (Malaysia)

1994-12-31

Equivalent circuits have been derived for microstrip ring resonator using transmission lines theory. From the analysis, two equations were derived. The first equation relates all the parameters of a ring into a single equation. This equation has been used in the design process to determine the ring dimensions. The second equation was used to calculate S sub 21 and was given as a function of relative permittivity, {epsilon} sub r, and angular frequency, {omega}. A procedure has been suggested on how these equations can be used to determine the value of {epsilon} sub r for an unknown substrate. The calculations using the data from experiment were compared with the values given by the manufacturer and was found to be within 8% different.

The results of the irradiations of microstrip detectors for the ATLAS tracker (SCT)

International Nuclear Information System (INIS)

Dervan, P.J.

2003-01-01

The SemiConductor Tracker (SCT) of ATLAS will operate in the Large Hadron Collider (LHC) at CERN, which will reach luminosities of 10 34 cm 2 s -1 . Silicon single-sided microstrip detectors will be used for particle tracking. Due to the proximity to the beam, the silicon detectors need to withstand damage from ionising radiation (10 Mrad total dose) and from non-ionising radiation such as neutrons (2x10 14 1 MeV equivalent neutrons/cm 2 total fluence). The final characteristics of the silicon SCT detectors which are needed to operate under LHC conditions and the conclusions reached after various years of test irradiation studies will be reported. The integration and performance of these detectors in complete SCT modules is also discussed

Programmable liquid crystal waveplate polarization gratings as elements for polarimetric and interference applications

Science.gov (United States)

Moreno, I.; Davis, J. A.

2010-06-01

We review the use of a parallel aligned nematic liquid crystal spatial light modulator as a very useful and flexible device for polarimetric and interferometric applications. The device acts as a programmable pixelated waveplate, and the encoding of a linear grating permits its use as a polarization beam splitter. When a grating with a reduced period is encoded, the diffracted beams are spatially separated and the device can be used for polarimetric analysis. On the contrary when a large period grating is displayed, the beams are not spatially separated, and they are useful to realize a common path interferometric system with polarization sensitivity. The flexibility offered by the programmability of the display allows non-conventional uses, including the analysis of light beams with structured spatial polarizations.

Local polarization phenomena in In-doped CdTe x-ray detector arrays

International Nuclear Information System (INIS)

Sato, Toshiyuki; Sato, Kenji; Ishida, Shinichiro; Kiri, Motosada; Hirooka, Megumi; Yamada, Masayoshi; Kanamori, Hitoshi

1995-01-01

Local polarization phenomena have been studied in detector arrays with the detector element size of 500 microm x 500 microm, which are fabricated from high-resistivity In-doped CdTe crystals grown by the vertical Bridgman technique. It has been found for the first time that a polarization effect, which is characterized by a progressive decrease of the pulse counting rate with increasing photon fluence, strongly depends on the detector elements, that is, the portion of crystals used. The influence of several parameters, such as the applied electric field strength, time, and temperature, on this local polarization effect is also investigated. From the photoluminescence measurements of the inhomogeneity of In dopant, it is concluded that the local polarization effect observed here originates from a deep level associated with In dopant in CdTe crystals

Integrated polarization beam splitter with relaxed fabrication tolerances.

Science.gov (United States)

Pérez-Galacho, D; Halir, R; Ortega-Moñux, A; Alonso-Ramos, C; Zhang, R; Runge, P; Janiak, K; Bach, H-G; Steffan, A G; Molina-Fernández, Í

2013-06-17

Polarization handling is a key requirement for the next generation of photonic integrated circuits (PICs). Integrated polarization beam splitters (PBS) are central elements for polarization management, but their use in PICs is hindered by poor fabrication tolerances. In this work we present a fully passive, highly fabrication tolerant polarization beam splitter, based on an asymmetrical Mach-Zehnder interferometer (MZI) with a Si/SiO(2) Periodic Layer Structure (PLS) on top of one of its arms. By engineering the birefringence of the PLS we are able to design the MZI arms so that sensitivities to the most critical fabrication errors are greatly reduced. Our PBS design tolerates waveguide width variations of 400nm maintaining a polarization extinction ratio better than 13dB in the complete C-Band.

Ferroelectric tunneling element and memory applications which utilize the tunneling element

Science.gov (United States)

Kalinin, Sergei V [Knoxville, TN; Christen, Hans M [Knoxville, TN; Baddorf, Arthur P [Knoxville, TN; Meunier, Vincent [Knoxville, TN; Lee, Ho Nyung [Oak Ridge, TN

2010-07-20

A tunneling element includes a thin film layer of ferroelectric material and a pair of dissimilar electrically-conductive layers disposed on opposite sides of the ferroelectric layer. Because of the dissimilarity in composition or construction between the electrically-conductive layers, the electron transport behavior of the electrically-conductive layers is polarization dependent when the tunneling element is below the Curie temperature of the layer of ferroelectric material. The element can be used as a basis of compact 1R type non-volatile random access memory (RAM). The advantages include extremely simple architecture, ultimate scalability and fast access times generic for all ferroelectric memories.

Polarity, veridicality and temporal connectives

NARCIS (Netherlands)

Sánchez Valencia, Victor; Wouden van der, Ton; Zwarts, Frans

1993-01-01

Introduction. The purpose of this paper is to draw attention to the semantical properties of before, after, and related elements. In particular, we shall raise the question whether the occurrence of negative polarity items in before-clauses can be described in terms of the semantic structure of the

Cladding-pumped ytterbium-doped fiber laser with radially polarized output.

Science.gov (United States)

Lin, Di; Daniel, J M O; Gecevičius, M; Beresna, M; Kazansky, P G; Clarkson, W A

2014-09-15

A simple technique for directly generating a radially polarized output beam from a cladding-pumped ytterbium-doped fiber laser is reported. Our approach is based on the use of a nanograting spatially variant waveplate as an intracavity polarization-controlling element. The laser yielded ~32 W of output power (limited by available pump power) with a radially polarized TM (01)-mode output beam at 1040 nm with a corresponding slope efficiency of 66% and a polarization purity of 95%. The beam-propagation factor (M(2)) was measured to be ~1.9-2.1.

Fabrication of a Polarizing Neutron Supermirror and Development of its applied Devices

International Nuclear Information System (INIS)

Cho, Sang Jin; Ryu, Ji Myoungi; Kim, Sangwon

2013-02-01

Based on the project of neutron guide development, which started in 2005, KAERI has possessed the techniques such as supermirror coating, guide element assembly, guide alignment, special tool development and guide element assembly, guide alignment, special tool development and guide maintenance. With help of multilayer coating technique from supermirror fabrication, a project called 'Development of a Polarizing Supermirror and its applied devices' started early 2011. To begin with, most used coating materials were investigated, and for using polarized beam, G-TS located at CG1 beam line (Guide Test Station: Reflectometer) was modified with adding spin flipper, polarizer, analyzer and magnetic sample holder developed by KAERI. By studying crystallization and oxidation of the FeCo alloy to minimize the layer roughness and magnetization of a magnetic layer to determine minimal magnetic field, the neutron polarizing supermirrors have been developed, which show a average reflectivity of 90% and a polarization of 95% for M=2 and a average reflectivity of 80% and a polarization of 95% for M=2.6

Scientific performances of the XAA1.2 front-end chip for silicon microstrip detectors

International Nuclear Information System (INIS)

Del Monte, Ettore; Soffitta, Paolo; Morelli, Ennio; Pacciani, Luigi; Porrovecchio, Geiland; Rubini, Alda; Uberti, Olga; Costa, Enrico; Di Persio, Giuseppe; Donnarumma, Immacolata; Evangelista, Yuri; Feroci, Marco; Lazzarotto, Francesco; Mastropietro, Marcello; Rapisarda, Massimo

2007-01-01

The XAA1.2 is a custom ASIC chip for silicon microstrip detectors adapted by Ideas for the SuperAGILE instrument on board the AGILE space mission. The chip is equipped with 128 input channels, each one containing a charge preamplifier, shaper, peak detector and stretcher. The most important features of the ASIC are the extended linearity, low noise and low power consumption. The XAA1.2 underwent extensive laboratory testing in order to study its commandability and functionality and evaluate its scientific performances. In this paper we describe the XAA1.2 features, report the laboratory measurements and discuss the results emphasizing the scientific performances in the context of the SuperAGILE front-end electronics

Polarized electrogowdy spacetimes censored

International Nuclear Information System (INIS)

Nungesser, Ernesto

2010-01-01

A sketch of the proof of strong cosmic censorship is presented for a class of solutions of the Einstein-Maxwell equations, those with polarized Gowdy symmetry. A key element of the argument is the observation that by means of a suitable choice of variables the central equations in this problem can be written in a form where they are identical to the central equations for general (i.e. non-polarized) vacuum Gowdy spacetimes. Using this it is seen that the results of Ringstroem on strong cosmic censorship in the vacuum case have implications for the Einstein-Maxwell case. Working out the geometrical meaning of these analytical results leads to the main conclusion.

Polarized electrogowdy spacetimes censored

Energy Technology Data Exchange (ETDEWEB)

Nungesser, Ernesto, E-mail: ernesto.nungesser@aei.mpg.d [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, Am Muehlenberg 1, 14476 Potsdam (Germany)

2010-05-01

A sketch of the proof of strong cosmic censorship is presented for a class of solutions of the Einstein-Maxwell equations, those with polarized Gowdy symmetry. A key element of the argument is the observation that by means of a suitable choice of variables the central equations in this problem can be written in a form where they are identical to the central equations for general (i.e. non-polarized) vacuum Gowdy spacetimes. Using this it is seen that the results of Ringstroem on strong cosmic censorship in the vacuum case have implications for the Einstein-Maxwell case. Working out the geometrical meaning of these analytical results leads to the main conclusion.

Effect of radiation-induced substrate defects on microstrip gas chamber gain behaviour

International Nuclear Information System (INIS)

Pallares, A.; Brom, J.M.; Bergdolt, A.M.; Coffin, J.; Eberle, H.; Sigward, M.H.; Fontaine, J.C.; Barthe, S.; Schunck, J.P.

1998-01-01

The aim of this work was to quantify the influence of radiation-induced substrate defects on microstrip gas chamber (MSGC) gain behaviour. The first part of this paper focuses on radiation effects on a typical MSGC substrate: Desag D263 glass. Defect generation was studied for Desag D263 with pure silica (Suprasil 1) as a reference. We studied the evolution of defect concentration with respect to accumulated doses up to 480 kGy. Annealing studies of defects in Desag D263 were also performed. In the second part, the radiation sensitivity of Desag D263 glass has been linked to the behaviour of the detector under irradiation. Comparative gain measurements were taken before and after substrate irradiation at 10 and 80 kGy the minimal dose received during LHC operation and the dose for which defect density is maximum (respectively). (orig.)

Microstrip gas chamber on thin-film Pestov glass and micro gap chamber

International Nuclear Information System (INIS)

Gong, W.G.; Harris, J.W.; Wieman, H.

1994-07-01

The authors report developments of the Microstrip Gas Chamber on thin-film Pestov glass and the Micro Gap Chamber. By coating a thin-layer of low-resistive, electronically-conductive glass on various substrates (including quartz and ceramics), they built MSGCs of high gain stability and low leakage current. They were tested in Ar-CH 4 (10%) and He-C 2 H 6 (50%) gas mixtures. Energy resolutions of 17-20% were measured for 6keV x-rays. This design can make the choice of substrate less important, save the cost of ion-implantation, and use less glass material. Micro Gap Chamber was successfully tested in He-C 2 H 6 (50%) and Ar-C 2 H 6 (50%) gas mixtures. Energy resolutions of about 20% were obtained. Both detectors are expected to have high rate capability

"Live from IPY"--Connecting Students, Teachers and the Public to Polar Research

Science.gov (United States)

Breen, K.; Warnick, W. K.; Warburton, J.; Fischer, K.; Wiggins, H.

2007-12-01

PolarTREC-Teachers and Researchers Exploring and Collaborating is a three-year (2007-2009) teacher professional development program of the Arctic Research Consortium of the U.S. (ARCUS) that pairs K-12 teachers with researchers to improve science education through authentic polar research experiences. Each year of PolarTREC, approximately 15 teachers spend two to six weeks in the Arctic or Antarctic, working closely with researchers investigating a wide range of topics such as sea-ice dynamics, terrestrial ecology, marine biology, atmospheric chemistry, and long-term climate change. PolarTREC is funded by the National Science Foundation. While in the field, teachers and researchers communicate extensively with their colleagues, communities, and hundreds of students of all ages across the globe, using a variety of communication technologies and tools to appeal to broad student and public engagement in polar science. Through the PolarTREC website (www.polartrec.com) teachers connect from the field through the use of online journals and forums, photo galleries, podcasts, and learning resources. "Live from IPY," a key activity of PolarTREC, is a free, interactive, distance-learning experience that virtually transports students and the public to unique and remote polar locations through a live Internet interface. Rather than relying solely on the asynchronous elements of online journals, forums, photo albums, and podcasts, "Live from IPY" allows real-time interaction by adding elements including live voice, video, chat, application sharing, polling, and whiteboards, but requires only telephone and/or Internet access for participants and presenters to connect. "Live from IPY" and the online outreach elements of PolarTREC convey the excitement of polar research experiences to a broad audience far beyond the classrooms of the PolarTREC teachers, allowing anyone to join a global network of scientists, teachers, students, and communities and actively participate in the

Development and operation of a novel PC-based high speed beam telescope for particle tracking using double sided silicon microstrip detectors

International Nuclear Information System (INIS)

Treis, J.

2002-08-01

A PC based high speed silicon microstrip beam telescope consisting of several independent modules is presented. Every module contains an AC-coupled double sided silicon microstrip sensor and a complete set of analog and digital signal processing electronics. A digital bus connects the modules with the DAQ PC. A trigger logic unit coordinates the operation of all modules of the telescope. The system architecture allows easy integration of any kind of device under test into the data acquisition chain. Signal digitization, pedestal correction, hit detection and zero suppression are done by hardware inside the modules, so that the amount of data per event is reduced by a factor of 80 compared to conventional readout systems. In combination with a two level data acquisition scheme, this allows event rates up to 7.6 kHz. This is a factor of 40 faster than conventional VME based beam telescopes while comparable analog performance is maintained achieving signal to noise ratios of up to 70:1. The telescope has been tested in the SPS testbeam at CERN. It has been adopted as the reference instrument for testbeam studies for the ATLAS pixel detector development. (orig.)

Development of microstrip gas chambers on substrata with electronic conductivity

International Nuclear Information System (INIS)

Bouclier, R.; Garabatos, C.; Manzin, G.; Sauli, F.; Shekhtman, L.; Temmel, T.; Della Mea, G.; Maggioni, G.; Rigato, V.; Logachenko, I.

1994-01-01

This paper describes several recent developments on Microstrip Gas Chambers (MSGCs). The authors have studied the operating behavior of the detectors in different gas mixtures; maximum stable gains have been achieved in mixtures of argon and dimethyl-ether (DME) in almost equal proportions. Using detectors manufactured on semi-conducting glass substrates, capable of withstanding very high rates (above 10 6 mm -2 s -1 ), they have demonstrated extended lifetime without gain modifications up to a collected charge of 130 mC cm -1 in clean laboratory operating conditions. They have also verified that relaxing the requirements on cleanness conditions, either in the gas mixing system or in the detector construction, may result in fast aging of the devices under irradiation. As an alternative to the semi-conducting glass, they have developed a novel technique to coat regular glass with a thin lead silicate layer having electron conductivity; a new development consisting in coating already manufactured MSGCs with the thin semi-conducting layer is also described. The preliminary results show an excellent rate capability of this kind of devices, intrinsically simpler to manufacture

Design of a Balun Bandpass Filter with Asymmetrical Coupled Microstrip Lines

Science.gov (United States)

Wang, Xuedao; Wang, Jianpeng; Zhang, Gang; Huang, Feng

2017-07-01

A new microstrip coupled-line balun topology and its application to the balun bandpass filter (BPF) with a triple mode response are proposed in this paper. The involved balun structure is composed of two back-to-back quarter-wavelength (λ/4) asymmetrical coupled-line sections. Detailed design formulas based on the asymmetrical coupled-line theory are given to validate the feasibility of the balun. Besides, to obtain filtering performance simultaneously, the balun is then effectively integrated with a pair of triple mode resonators. To demonstrate the design concept of the balun BPF, a prototype operating at 2.4 GHz with the fractional bandwidth (FBW) of about 19.2 % is designed, fabricated, and measured. Results indicate that between the two balanced outputs, the amplitude imbalance is less than 0.3 dB and the phase difference is within 180°±5° inside the whole passband. Both simulated and experimental results are in good agreement.

A proposal to use microstrip gas counters in a LHC tracker

International Nuclear Information System (INIS)

Geijsberts, M.; Hartjes, F.G.; Pannekoek, J.G.; Schmitz, J.; Udo, F.

1991-06-01

The paper presents an LHC tracker constructed from microstrip gas counters, occupying a cylinder around the beam r=400 mm and r=900 mm. The instrument measures 12 points on track with an accuracy of 30μm. Due to fine granularity and the short charge collection time, the occupancy is below 1 percent at a luminosity of L=10 34 cm -2 . Operating at high magnetic fields and a fast charge collection process are possible using Xe/DME/CO 2 mixtures and reducing the gap width between substrate and drift cathode to 1.6 mm. Hits from low energetic tracks are largely suppressed and hard tracks stand out, which greatly facilitates pattern recognition. By introducing a small stereo angle, the (r,z) coordinate can be measured with an accuracy of 1 mm. A calculation of the collected charge per strip shows that the tracker can withstand the LHC radiation for many years. (author). 9 refs.; 7 figs

Test of the CMS microstrip silicon tracker readout and control system

CERN Document Server

Zghiche, A

2001-01-01

The Microstrip Silicon tracker of the CMS detector is designed to provide robust particle tracking and vertex reconstruction within a strong magnetic field in the high luminosity environment of the LHC. The Tracker readout system employs Front-End Driver cards to digitize and buffer the analogue data arriving via optical links from on detector pipeline chips. The control chain of the front-end electronic is built to operate via optical fibers in order to shield the communications from the outside noise. Components close to the final design have been assembled to be tested in the X5 beam area at CERN where a dedicated 25 ns temporal structure beam has been made available by the SPS. This paper describes the hardware and the software developed for readout and control of data acquired by the front-end electronics operating at 40 MHz, Some preliminary results of the tests performed in the 25 ns beam are also given. (8 refs).

A gas microstrip detector for X-ray imaging with readout of the anode by resistive division

CERN Document Server

Bateman, J E; Lodge, A B; Stephenson, R; Mutikainen, R; Suni, I; Morse, J

2002-01-01

The results are presented of a development programme aimed at the validation of the key concepts and technologies for the construction of a two-dimensional X-ray detector based on gas microstrip detector technology using resistive division along the anode to achieve the second dimension. A prototype detector and its associated electronic readout system have been developed which demonstrate the capability of a spatial resolution (standard deviation) of approximately ((1)/(1000)) of the working aperture combined with readout rates of up to 400 kHz per anode. Test results and a description of the position sensing circuitry are given.

High Density Interconnect Microstrip Patch Antenna for 5G Base Stations with Integrated Filtering Performance

Directory of Open Access Journals (Sweden)

Marco Salucci

2018-04-01

Full Text Available The elementary radiator of a planar array for next generation millimeter-wave (mm-wave 5G base stations is described. The antenna is designed for high density interconnect (HDI manufacturing for yielding a compact, densely-interconnected, and highly-integrable stacked structure. The layout of the single element is determined by directly optimizing key radiation features of the whole planar arrangement according to specific application-driven requirements. In addition, thanks to the exploitation of a spline-shaped modelling of the radiator, suitable performance in terms of impedance matching, realized gain, half-power beamwidth (HPBW, polarization purity, and inter-element isolation are achieved within the 28-GHz pass-band. Moreover, integrated out-of-band filtering capabilities are obtained in selected and wide non-contiguous stop-bands without additional circuitry.

Reconfigurable micromachined antenna with polarization diversity for mm-wave applications

KAUST Repository

Sallam, Mai O.

2012-03-01

In this paper a novel MEMS antenna with reconfigurable polarization operating at 60 GHz is presented. This antenna can provide vertical linear polarization, horizontal linear polarization, left hand circular polarization (LHCP), or right hand circular polarization (RHCP) based on the states of the switches present in the feeding network. The proposed antenna is characterized by having its radiating elements isolated from the feeding circuitry via a ground plane without the need for wafer bonding or hybrid integration. Such advantage results in good electric performance while maintains low fabrication cost. The antenna parameters are optimized using HFSS and the results are cross-validated using CST. The good agreement between the two simulators, confirms that the proposed antenna enjoys attractive radiation characteristics for all polarization senses. © 2012 IEEE.

Reconfigurable micromachined antenna with polarization diversity for mm-wave applications

KAUST Repository

Sallam, Mai O.; Soliman, Ezzeldin A.; Sedky, Sherif

2012-01-01

In this paper a novel MEMS antenna with reconfigurable polarization operating at 60 GHz is presented. This antenna can provide vertical linear polarization, horizontal linear polarization, left hand circular polarization (LHCP), or right hand circular polarization (RHCP) based on the states of the switches present in the feeding network. The proposed antenna is characterized by having its radiating elements isolated from the feeding circuitry via a ground plane without the need for wafer bonding or hybrid integration. Such advantage results in good electric performance while maintains low fabrication cost. The antenna parameters are optimized using HFSS and the results are cross-validated using CST. The good agreement between the two simulators, confirms that the proposed antenna enjoys attractive radiation characteristics for all polarization senses. © 2012 IEEE.

Vacuum ultraviolet spectropolarimeter design for precise polarization measurements.

Science.gov (United States)

Narukage, Noriyuki; Auchère, Frédéric; Ishikawa, Ryohko; Kano, Ryouhei; Tsuneta, Saku; Winebarger, Amy R; Kobayashi, Ken

2015-03-10

Precise polarization measurements in the vacuum ultraviolet (VUV) region provide a new means for inferring weak magnetic fields in the upper atmosphere of the Sun and stars. We propose a VUV spectropolarimeter design ideally suited for this purpose. This design is proposed and adopted for the NASA-JAXA chromospheric lyman-alpha spectropolarimeter (CLASP), which will record the linear polarization (Stokes Q and U) of the hydrogen Lyman-α line (121.567 nm) profile. The expected degree of polarization is on the order of 0.1%. Our spectropolarimeter has two optically symmetric channels to simultaneously measure orthogonal linear polarization states with a single concave diffraction grating that serves both as the spectral dispersion element and beam splitter. This design has a minimal number of reflective components with a high VUV throughput. Consequently, these design features allow us to minimize the polarization errors caused by possible time variation of the VUV flux during the polarization modulation and by statistical photon noise.

A multi-channel integrated circuit for the readout of a microstrip gas chamber

Energy Technology Data Exchange (ETDEWEB)

Krummenacher, F.; Enz, C. (Smart Silicon Systems S.A., Lausanne (Switzerland)); Bellazzini, R. (Dipt. di Fisica, Pisa (Italy) INFN, Pisa (Italy))

1992-03-15

The design and test of an 8 channel integrated circuit for the readout of the microstrip gas chamber and other multielectrode detectors are described. The circuit is composed of 8 identical channels, each providing the amplification and the shaping of the signal delivered by the detector. The peaking time of the shaper is 25 ns and the overall amplifier gain is 8 mV/1000 e{sup -}. In addition to the analog output, each channel provides a TTL compatible digital output. The equivalent input noise is less than 700 e{sup -} rms and the total dc power consumption is about 5 mW/channel. To avoid a baseline shift due to the tail of the current issued from the detector, an adjustable pole-zero cancellation circuit has been included. (orig.).

Solar Polar Field Observed by SOHO/MDI and Hinode

Science.gov (United States)

Liu, Y.

2009-12-01

Using 1-minute cadence time-series full disk magnetograms taken by SOHO/MDI in 2007 March, and the corresponding Hinode/SOT vector magnetograms, I have studied evolutionary characteristics of magnetic elements in Sun's south polar region in solar minimum. It is found that the lifetime of magnetic elements is 17.0 hours on average with an average lifetime of 21.8 hours for elements with positive field, the dominant polarity in the south pole, and 1.6 hours for elements with negative field. The elements with positive field are dominant in the south pole with a percentage of 76% in element number and 90.5% in magnetic flux. The lifetime and magnetic flux of the elements is found to be highly related. This agrees with some previous studies for the elements in low latitude quiet regions. Using an image cross correlation method, I also measure solar rotation rate at high latitude, up to 85° in latitude, which is ω = 2.914-0.342 × sin2φ-0.482×sin4φ μrad/s sidereal. It agrees with previous studies using spectroscopic and image cross correlation methods, and also agrees with the results from some work using the element tracking method in which the sample of tracked elements is large. The consistency of those results from different data and methods strongly suggests that this rate at high latitude is reliable.

Analysis of Circularly Polarized Hemispheroidal Dielectric Resonator Antenna Phased Arrays Using the Method of Auxiliary Sources

DEFF Research Database (Denmark)

Larsen, Niels Vesterdal; Breinbjerg, Olav

2007-01-01

The method of auxiliary sources is employed to model and analyze probe-fed hemispheroidal dielectric resonator antennas and arrays. Circularly polarized antenna elements of different designs are analyzed, and impedance bandwidths of up to 14.7% are achieved. Selected element designs are subsequen......The method of auxiliary sources is employed to model and analyze probe-fed hemispheroidal dielectric resonator antennas and arrays. Circularly polarized antenna elements of different designs are analyzed, and impedance bandwidths of up to 14.7% are achieved. Selected element designs...

High-power laser diodes with high polarization purity

Science.gov (United States)

Rosenkrantz, Etai; Yanson, Dan; Peleg, Ophir; Blonder, Moshe; Rappaport, Noam; Klumel, Genady

2017-02-01

Fiber-coupled laser diode modules employ power scaling of single emitters for fiber laser pumping. To this end, techniques such as geometrical, spectral and polarization beam combining (PBC) are used. For PBC, linear polarization with high degree of purity is important, as any non-perfectly polarized light leads to losses and heating. Furthermore, PBC is typically performed in a collimated portion of the beams, which also cancels the angular dependence of the PBC element, e.g., beam-splitter. However, we discovered that single emitters have variable degrees of polarization, which depends both on the operating current and far-field divergence. We present data to show angle-resolved polarization measurements that correlate with the ignition of high-order modes in the slow-axis emission of the emitter. We demonstrate that the ultimate laser brightness includes not only the standard parameters such as power, emitting area and beam divergence, but also the degree of polarization (DoP), which is a strong function of the latter. Improved slow-axis divergence, therefore, contributes not only to high brightness but also high beam combining efficiency through polarization.

Studies of kinematic elements in two multicenter sunspot groups

International Nuclear Information System (INIS)

Korobova, Z.B.

1983-01-01

Some features of kinematic elements (KE) in two multicenter sunspot groups were studied using Tashkent full-disc white light heliograms. KE and morphological elements do not reveal any relationship. A KE coincides with a unipolar or multipolar spot or with part of a spot. It may also contain an extended stream including several spots. Relation of KE to large-scale photospheric magnetic fields is less clear. The line of polarity reversal is, in most cases, the deviding line between two adjacent KE. At the same time, a KE can contain spots of both polarities. Sunspot trajectories in the leading polarity regions show the best similarity. Interactions of KE are greatly influenced by the meridional drift. (author)

Development and evaluation of test stations for the quality assurance of the silicon micro-strip detector modules for the CMS experiment

International Nuclear Information System (INIS)

Poettgens, M.

2007-01-01

CMS (Compact Muon Solenoid) is one of four large-scale detectors which will be operated at the LHC (Large Hadron Collider) at the European Laboratory for Particle Physics (CERN). For the search for new physics the reconstruction of the collision products and their properties is essential. In the innermost part of the CMS detector the traces of ionizing particles are measured utilizing a silicon tracker. A large fraction of this detector is equipped with silicon micro-strip modules which provide a precise space resolution in 1-dimension. A module consists of a sensor for detection of particles, the corresponding read-out electronics (hybrid) and a mechanical support structure. Since the 15,148 modules, which will be installed in the silicon micro-strip detector, have a total sensitive surface area of about 198 m 2 , the inner tracker of CMS is the largest silicon tracking detector, which has ever been built. While the sensors and hybrids are produced in industry, the construction of the modules and the control of the quality is done by the members of the 21 participating institutes. Since the access to the silicon micro-strip tracker will be very limited after the installation in the CMS detector the installed modules must be of high quality. For this reason the modules are thoroughly tested and the test results are uploaded to a central database. By the development of a read-out system and the corresponding software the III. Physikalisches Institut made an important contribution for the electrical and functional quality control of hybrids and modules. The read-out system provides all features for the operation and test of hybrids and modules and stands out due to high reliability and simple handling. Because a very user-friedly and highly automated software it became the official test tool and was integrated in various test stands. The test stands, in which the read-out system is integrated in, are described and the tests which are implemented in the corresponding

Development and evaluation of test stations for the quality assurance of the silicon micro-strip detector modules for the CMS experiment

Energy Technology Data Exchange (ETDEWEB)

Poettgens, M.

2007-11-22

CMS (Compact Muon Solenoid) is one of four large-scale detectors which will be operated at the LHC (Large Hadron Collider) at the European Laboratory for Particle Physics (CERN). For the search for new physics the reconstruction of the collision products and their properties is essential. In the innermost part of the CMS detector the traces of ionizing particles are measured utilizing a silicon tracker. A large fraction of this detector is equipped with silicon micro-strip modules which provide a precise space resolution in 1-dimension. A module consists of a sensor for detection of particles, the corresponding read-out electronics (hybrid) and a mechanical support structure. Since the 15,148 modules, which will be installed in the silicon micro-strip detector, have a total sensitive surface area of about 198 m{sup 2}, the inner tracker of CMS is the largest silicon tracking detector, which has ever been built. While the sensors and hybrids are produced in industry, the construction of the modules and the control of the quality is done by the members of the 21 participating institutes. Since the access to the silicon micro-strip tracker will be very limited after the installation in the CMS detector the installed modules must be of high quality. For this reason the modules are thoroughly tested and the test results are uploaded to a central database. By the development of a read-out system and the corresponding software the III. Physikalisches Institut made an important contribution for the electrical and functional quality control of hybrids and modules. The read-out system provides all features for the operation and test of hybrids and modules and stands out due to high reliability and simple handling. Because a very user-friedly and highly automated software it became the official test tool and was integrated in various test stands. The test stands, in which the read-out system is integrated in, are described and the tests which are implemented in the

Effect of radiation-induced substrate defects on microstrip gas chamber gain behaviour

Energy Technology Data Exchange (ETDEWEB)

Pallares, A.; Brom, J.M.; Bergdolt, A.M.; Coffin, J.; Eberle, H.; Sigward, M.H. [Institute de Recherches Subatomiques, 67 - Strasbourg (France); Fontaine, J.C. [Universite de Haute Alsace, GRPHE, 61 rue Albert Camus, 68093 Mulhouse Cedex (France); Barthe, S.; Schunck, J.P. [Laboratoire PHASE (UPR 292 du CNRS), 23 rue du Loess, BP 28, 67037 Strasbourg Cedex 2 (France)

1998-08-01

The aim of this work was to quantify the influence of radiation-induced substrate defects on microstrip gas chamber (MSGC) gain behaviour. The first part of this paper focuses on radiation effects on a typical MSGC substrate: Desag D263 glass. Defect generation was studied for Desag D263 with pure silica (Suprasil 1) as a reference. We studied the evolution of defect concentration with respect to accumulated doses up to 480 kGy. Annealing studies of defects in Desag D263 were also performed. In the second part, the radiation sensitivity of Desag D263 glass has been linked to the behaviour of the detector under irradiation. Comparative gain measurements were taken before and after substrate irradiation at 10 and 80 kGy the minimal dose received during LHC operation and the dose for which defect density is maximum (respectively). (orig.) 26 refs.

Computing resonant frequency of C-shaped compact microstrip antennas by using ANFIS

Science.gov (United States)

Akdagli, Ali; Kayabasi, Ahmet; Develi, Ibrahim

2015-03-01

In this work, the resonant frequency of C-shaped compact microstrip antennas (CCMAs) operating at UHF band is computed by using the adaptive neuro-fuzzy inference system (ANFIS). For this purpose, 144 CCMAs with various relative dielectric constants and different physical dimensions were simulated by the XFDTD software package based on the finite-difference time domain (FDTD) method. One hundred and twenty-nine CCMAs were employed for training, while the remaining 15 CCMAs were used for testing of the ANFIS model. Average percentage error (APE) values were obtained as 0.8413% and 1.259% for training and testing, respectively. In order to demonstrate its validity and accuracy, the proposed ANFIS model was also tested over the simulation data given in the literature, and APE was obtained as 0.916%. These results show that ANFIS can be successfully used to compute the resonant frequency of CCMAs.

Compact Microstrip Triple-Mode Bandpass Filters Using Dual-Stub-Loaded Spiral Resonators

Directory of Open Access Journals (Sweden)

K. D. Xu

2017-04-01

Full Text Available Two new microstrip triple-mode resonators loaded with T-shaped open stubs using axially and centrally symmetric spiral structures, respectively, are presented. Spiraled for circuit size reduction, these two half-wavelength resonators can both generate three resonant modes over a wide frequency band by loading two T-stubs with different lengths. Due to the structural symmetry, they can be analyzed by odd- and even-mode method. To validate the design concept, two compact bandpass filters (BPFs using these two novel resonators with center frequencies of 1.76 GHz and 2.44 GHz for the GSM1800 and WLAN/Zigbee applications, respectively, have been designed, fabricated and tested. The center frequencies and bandwidths can be tunable through the analysis of resonant frequency responses, fractional bandwidths and external quality factor versus the resonator parameters. The final measured results have achieved good consistence with the simulations of these two BPFs.

Nonuniform Overlapping Method in Designing Microstrip Patch Antennas Using Genetic Algorithm Optimization

Directory of Open Access Journals (Sweden)

J. M. Jeevani W. Jayasinghe

2015-01-01

Full Text Available Genetic algorithm (GA has been a popular optimization technique used for performance improvement of microstrip patch antennas (MPAs. When using GA, the patch geometry is optimized by dividing the patch area into small rectangular cells. This has an inherent problem of adjacent cells being connected to each other with infinitesimal connections, which may not be achievable in practice due to fabrication tolerances in chemical etching. As a solution, this paper presents a novel method of dividing the patch area into cells with nonuniform overlaps. The optimized design, which is obtained by using fixed overlap sizes, shows a quad-band performance covering GSM1800, GSM1900, LTE2300, and Bluetooth bands. In contrast, use of nonuniform overlap sizes leads to obtaining a pentaband design covering GSM1800, GSM1900, UMTS, LTE2300, and Bluetooth bandswith fractional bands with of 38% due to the extra design flexibility.

Characterization and spice simulation of a single-sided, p+ on n silicon microstrip detector before and after low-energy photon irradiation

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jiaguo; Klanner, Robert; Fretwurst, Eckhart [Institute for Experimental Physics, Detector Laboratory, University of Hamburg, Hamburg 22761 (Germany)

2010-07-01

As preparation for the development of silicon detectors for the harsh radiation environment at the European XFEL (up to 1 GGY 12 keV X-rays) p{sup +} on n silicon microstrip detectors were characterized as function of dose. The measurements, which include dark current, coupling capacitance, interstrip capacitance and interstrip resistance, are compared to a detailed SPICE model, so that the performance for particle detection can be estimated.

Slim planar apparatus for converting LED light into collimated polarized light uniformly emitted from its top surface.

Science.gov (United States)

Teng, Tun-Chien; Tseng, Li-Wei

2014-10-20

This study proposes a slim planar apparatus for converting nonpolarized light from a light-emitting diode (LED) into an ultra-collimated linearly polarized beam uniformly emitted from its top surface. The apparatus was designed based on a folded-bilayer configuration comprising a light-mixing collimation element, polarization conversion element, and polarization-preserving light guide plate (PPLGP) with an overall thickness of 5 mm. Moreover, the apparatus can be extended transversally by connecting multiple light-mixing collimation elements and polarization conversion elements in a side-by-side configuration to share a considerably wider PPLGP, so the apparatus can have theoretically unlimited width. The simulation results indicate that the proposed apparatus is feasible for the maximal backlight modules in 39-inch liquid crystal panels. In the case of an apparatus with a 480 × 80 mm emission area and two 8-lumen LED light sources, the average head-on polarized luminance and spatial uniformity over the emission area was 5000 nit and 83%, respectively; the vertical and transverse angular distributions of the emitting light were only 5° and 10°, respectively. Moreover, the average degree of polarization and energy efficiency of the apparatus were 82% and 72%, respectively. As compared with the high-performance ultra-collimated nonpolarized backlight module proposed in our prior work, not only did the apparatus exhibit outstanding optical performance, but also the highly polarized light emissions actually increased the energy efficiency by 100%.

Polar User’s Manual.

Science.gov (United States)

1985-10-01

spere 4 .11 . Flig us -pee 4.2-I 4.21 FINITE ELEMENTS 4.21.1 GENERAL Consider a charged object isolated in space. The potential 6 everywhere is given...Belo, fom eftto rghtarequai- spere ocago righ cylnde, teraheron w de, ad rctanula paraleleiped 6.1-6 TABLE 6/1. POLAR BUILDING BLOCKS AND THEIR KEYWORDS

Tungsten behaviour under anodic polarization

International Nuclear Information System (INIS)

Vas'ko, A.T.; Patsyuk, F.N.

1980-01-01

Electrochemical investigations have been carried out to identify the state of elements of the tungsten galvanic coating. Active zones on anode polarization curves in the hydrogen region of galvanic tungsten are established. The difference in the behaviour of monocrystal and galvanic tungsten electrodes is shown to be connected with the oxidation of hydrogen in the galvanic sediment

Probing Quark-Gluon Interactions with Transverse Polarized Scattering

International Nuclear Information System (INIS)

Rondon, Oscar A.

2011-01-01

Transverse polarized inelastic scattering extends the power of the electromagnetic interaction as a probe of nucleon dynamics beyond the leading order regime explored with longitudinally polarized DIS. In transverse polarized scattering, the twist-3 g 2 spin structure function contributes at the same order as the longitudinal, twist-2, g 1 , so interactions between quarks and gluons can be studied, opening a window on the mechanisms of confinement. This talk reports the results of Jefferson Lab's Resonances Spin Structure experiment measurement of g 2 and the d 2 twist-3 quark matrix element at a four-momentum transfer of 1.3 GeV 2 .

A SPICE model of double-sided Si microstrip detectors

International Nuclear Information System (INIS)

Candelori, A.; Paccagnella, A.; Bonin, F.

1996-01-01

We have developed a SPICE model for the ohmic side of AC-coupled Si microstrip detectors with interstrip isolation via field plates. The interstrip isolation has been measured in various conditions by varying the field plate voltage. Simulations have been compared with experimental data in order to determine the values of the model parameters for different voltages applied to the field plates. The model is able to predict correctly the frequency dependence of the coupling between adjacent strips. Furthermore, we have used such model for the study of the signal propagation along the detector when a current signal is injected in a strip. Only electrical coupling is considered here, without any contribution due to charge sharing derived from carrier diffusion. For this purpose, the AC pads of the strips have been connected to a read-out electronics and the current signal has been injected into a DC pad. Good agreement between measurements and simulations has been reached for the central strip and the first neighbors. Experimental tests and computer simulations have been performed for four different strip and field plate layouts, in order to investigate how the detector geometry affects the parameters of the SPICE model and the signal propagation

A low-noise X-band microstrip VCO with 2.5 GHz tuning range using a GaN-on-SiC p-HEMT

NARCIS (Netherlands)

Maas, A.M.P.; Vliet, F.E. van

2005-01-01

A low-noise X-band microstrip hybrid VCO has been designed and realised using a 2 × 50 μm GaN-on-SiC pseudo-morphic HEMT as the active device. The transistor has been manufactured by TIGER and features a gate-length of 0.15 μm, an fT of 22 GHz, a break-down voltage of 42 Volts and an Idss, close to

Planar ESPAR Array Design with Nonsymmetrical Pattern by Means of Finite-Element Method, Domain Decomposition, and Spherical Wave Expansion

Directory of Open Access Journals (Sweden)

Jesús García

2012-01-01

Full Text Available The application of a 3D domain decomposition finite-element and spherical mode expansion for the design of planar ESPAR (electronically steerable passive array radiator made with probe-fed circular microstrip patches is presented in this work. A global generalized scattering matrix (GSM in terms of spherical modes is obtained analytically from the GSM of the isolated patches by using rotation and translation properties of spherical waves. The whole behaviour of the array is characterized including all the mutual coupling effects between its elements. This procedure has been firstly validated by analyzing an array of monopoles on a ground plane, and then it has been applied to synthesize a prescribed radiation pattern optimizing the reactive loads connected to the feeding ports of the array of circular patches by means of a genetic algorithm.

600 GHz resonant mode in a parallel array of Josephson tunnel junctions connected by superconducting microstrip lines

DEFF Research Database (Denmark)

Kaplunenko, V. K.; Larsen, Britt Hvolbæk; Mygind, Jesper

1994-01-01

on experimental and numerical investigations of a resonant step observed at a voltage corresponding to 600 GHz in the dc current-voltage characteristic of a parallel array of 20 identical small NbAl2O3Nb Josephson junctions interconnected by short sections of superconducting microstrip line. The junctions...... are mutually phase locked due to collective interaction with the line sections excited close to the half wavelength resonance. The phase locking range can be adjusted by means of an external dc magnetic field and the step size varies periodically with the magnetic field. The largest step corresponds...

Dual-band dual-polarized array for WLAN applications

CSIR Research Space (South Africa)

Steyn, JM

2009-01-01

Full Text Available dual-band dual-polarized (DBDP) antenna design for WLAN applications. The antenna is in the form of an array consisting of four double-dipole radiators. The basic radiating element consists of a rhombus shaped dipole above a planar ground plane... the ground planes and the respective feedlines. Substrate cuts and difierent heights for the horizontal feedlines were necessary to achieve the latter. The 2nd conflguration (for vertical polarization) has a slightly difierent feeding network layout...

Platform for Manipulating Polarization Modes Realized with Jones Vectors in MATHEMATICA

Directory of Open Access Journals (Sweden)

Yong-Dae Choi

2015-06-01

Full Text Available The fundamental conception in physics of the propagation of the electromagnetic wave polarization in matter is newly understood as the cardinal keyword in free-space quantum communication technology and cosmology in astrophysics. Interactive visualization of the propagation mechanism of polarized electromagnetism in a medium with its helicity has accordingly received attention from scientists exploiting the protocol of quantum key distribution (QKD to guarantee unconditional security in cryptography communication. We have provided a dynamic polarization platform for presenting the polarization modes of a transverse electromagnetic wave, converting the state of polarization through the arrangement of optical elements, using Jones vectors calculations in Methematica. The platform graphically simulates the mechanism of production and propagation of the polarized waves in a medium while satisfying Maxwell's equations.

Design of Small CRPA Arrays with Circular Microstrip Loops for Electromagnetically Coupled Feed

Directory of Open Access Journals (Sweden)

Jun Hur

2018-04-01

Full Text Available This paper proposes a design of small controlled reception pattern antenna (CRPA arrays using circular microstrip loops with frequencyinsensitive characteristics. The proposed array consists of seven identical upper and lower circular loops that are electromagnetically coupled, which results in a frequency-insensitive behavior. To demonstrate the feasibility of the proposed feeding mechanism, the proposed array is fabricated, and its antenna characteristics are measured in a full-anechoic chamber. The operating principle of the proposed feeding mechanism is then interpreted using an equivalent circuit model, and the effectiveness of the circular loop shape is demonstrated by calculating near electromagnetic fields in proximity to the radiator. The results confirm that the proposed feeding mechanism is suitable to have frequency-insensitive behavior and induces strong electric and magnetic field strengths for higher radiation gain in extremely small antenna arrays.

A VLSI front-end circuit for microstrip silicon detectors for medical imaging applications

International Nuclear Information System (INIS)

Beccherle, R.; Cisternino, A.; Guerra, A. Del; Folli, M.; Marchesini, R.; Bisogni, M.G.; Ceccopieri, A.; Rosso, V.; Stefanini, A.; Tripiccione, R.; Kipnis, I.

1999-01-01

An analog CMOS-Integrated Circuit has been developed as Front-End for a double-sided microstrip silicon detector. The IC processes and discriminates signals in the 5-30 keV energy range. Main features are low noise and precise timing information. Low noise is achieved by optimizing the cascoded integrator with the 8 pF detector capacitance and by using an inherently low noise 1.2 μm CMOS technology. Timing information is provided by a double discriminator architecture. The output of the circuit is a digital pulse. The leading edge is determined by a fixed threshold discriminator, while the trailing edge is provided by a zero crossing discriminator. In this paper we first describe the architecture of the Front-End chip. We then present the performance of the chip prototype in terms of noise, minimum discrimination threshold and time resolution

Micro-strip Metal Foil Detectors for the Beam Profile Monitoring

CERN Document Server

Pugatch, V M; Fedorovitch, O A; Mikhailenko, A V; Prystupa, S V; Pylypchenko, Y

2005-01-01

The Micro-strip Metal Foil Detectors (MMFD) designed and used for the Beam Profile Monitoring (BPM) are discussed. Fast particles hitting a metal strip initiate Secondary Electron Emission (SEE) which occurs at 10 - 50 nm surface layers of a strip. The SEE yield is measured by a sensitive Charge Integrator with built-in current-to-frequency converter (1 Hz per 1 fA). The MMFD (deposited onto the 20 μm thick Si-wafer) with 32 Al strips (10 μm wide, 32 μm pitch) has been used for the BPM of the 32 MeV alpha-particle beam at the MPIfK (Heidelberg) Tandem generator for Single-Event-Upset studies of the BEETLE micro-chip. Similar MMFD (0.5 μm thick Ni-strips) with totally removed Si-wafer (by plasma-chemistry, at the working area of 8 x 10 mm2) has been applied for the on-line X-ray BPM at the HASYLAB (DESY). The number of photons (11.3 GeV, mean X-ray energy 18 keV) producing out of a strip a single SEE was evaluated as (1.5 ±0.5)* 104. MMFD has demonstrated stable...

Design, Manufacturing, and Testing of a 20/30-GHz Dual-Band Circularly Polarized Reflectarray Antenna

DEFF Research Database (Denmark)

Smith, Thomas Gunst; Gothelf, Ulrich; Kim, Oleksiy S.

2013-01-01

This letter documents the design, manufacturing, and testing of a single-layer dual-band circularly polarized reflectarray antenna for 19.7–20.2 and 29.5–30.0 GHz. The reflectarray is designed using the concentric dual split-loop element and the variable rotation technique that enables full 360......$^{\\circ}$ phase adjustment simultaneously in two separate frequency bands. The elements have been optimized to suppress cross-polar reflection. Thereafter, the element data is included in a design tool that computes the reflectarray layout and the associated radiation patterns. The reflectarray...

HF filter design and computer simulation

CERN Document Server

Rhea, Randall W

1994-01-01

A book for engineers who design and build filters of all types, including lumped element, coaxial, helical, dielectric resonator, stripline and microstrip types. A thorough review of classic and modern filter design techniques, containing extensive practical design information of passband characteristics, topologies and transformations, component effects and matching. An excellent text for the design and construction of microstrip filters.

Signals from fluorescent materials on the surface of silicon micro-strip sensors

CERN Document Server

Sperlich, Dennis; The ATLAS collaboration

2017-01-01

For the High-Luminosity Upgrade of the Large Hadron Collider at CERN, the ATLAS Inner Detector will be replaced with a new, all-silicon tracker. In order to minimise the amount of material in the detector, circuit boards with readout electronics will be glued on to the active area of the sensor. Several adhesives investigated to be used for the construction of detector modules were found to become fluorescent when exposed to UV light. These adhesives could become a light source in the high-radiation environment of the ATLAS detector. The effect of fluorescent material covering the sensor surface in a high- radiation environment has been studied for a silicon micro-strip sensor using a micro-focused X-ray beam. By pointing the beam both inside the sensor and parallel to the sensor surface, the sensor responses from direct hits and fluorescence can be compared with high precision. This contribution presents a setup to study the susceptibility of silicon strip sensors to light contamination from fluorescent mate...

Planar Microstrip Ring Resonators for Microwave-Based Gas Sensing: Design Aspects and Initial Transducers for Humidity and Ammonia Sensing.

Science.gov (United States)

Bogner, Andreas; Steiner, Carsten; Walter, Stefanie; Kita, Jaroslaw; Hagen, Gunter; Moos, Ralf

2017-10-24

A planar microstrip ring resonator structure on alumina was developed using the commercial FEM software COMSOL. Design parameters were evaluated, eventually leading to an optimized design of a miniaturized microwave gas sensor. The sensor was covered with a zeolite film. The device was successfully operated at around 8.5 GHz at room temperature as a humidity sensor. In the next step, an additional planar heater will be included on the reverse side of the resonator structure to allow for testing of gas-sensitive materials under sensor conditions.

Battery-less wireless interrogation of microstrip patch antenna for strain sensing

International Nuclear Information System (INIS)

Xu, X; Huang, H

2012-01-01

This paper presents a battery-less wireless interrogation system that can measure the resonant frequency of a microstrip patch antenna with a fine resolution. Since the antenna resonant frequency is sensitive to strain-induced deformations, wireless interrogation of the antenna sensor for strain measurement was demonstrated. By implementing a microwatt impedance switching circuit at the sensor node, the antenna backscattering is amplitude modulated at the sensor node so that it can be separated from the structural backscattering at the interrogator. The sensor node can be powered by a small photocell and thus achieve battery-less operation. The operating principle of the wireless interrogation system is first described, followed by the implementation and characterization of the wireless interrogation system. The antenna resonant frequency shifts were correlated to the applied strains through a static tensile experiment. An excellent agreement between the experimental results and the analytical prediction was obtained. A power transmission model was established and validated with experimental measurements. Based on this power transmission model, we estimated that the maximum interrogation distance of the wireless strain measurement system is 26 m. (paper)

Enabling Technologies for Silicon Microstrip Tracking Detectors at the HL-LHC

CERN Document Server

Barth, C; Bloch, I.; Bögelspacher, F.; de Boer, W.; Daniels, M.; Dierlamm, A.; Eber, R.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Erfle, J.; Feld, L.; Garutti, E.; Gregor, I. -M.; Guthoff, M.; Hartmann, F.; Hauser, M.; Husemann, U.; Jakobs, K.; Junkes, A.; Karpinski, W.; Klein, K.; Kuehn, S.; Lacker, H.; Mahboubi, K.; Müller, Th.; Mussgiller, A.; Nürnberg, A.; Parzefall, U.; Poehlsen, T.; Poley, L.; Preuten, M.; Rehnisch, L.; Sammet, J.; Schleper, P.; Schuwalow, S.; Sperlich, D.; Stanitzki, M.; Steinbrück, G.; Wlochal, M.

2016-01-01

While the tracking detectors of the ATLAS and CMS experiments have shown excellent performance in Run 1 of LHC data taking, and are expected to continue to do so during LHC operation at design luminosity, both experiments will have to exchange their tracking systems when the LHC is upgraded to the high-luminosity LHC (HL-LHC) around the year 2024. The new tracking systems need to operate in an environment in which both the hit densities and the radiation damage will be about an order of magnitude higher than today. In addition, the new trackers need to contribute to the first level trigger in order to maintain a high data-taking efficiency for the interesting processes. Novel detector technologies have to be developed to meet these very challenging goals. The German groups active in the upgrades of the ATLAS and CMS tracking systems have formed a collaborative "Project on Enabling Technologies for Silicon Microstrip Tracking Detectors at the HL-LHC" (PETTL), which was supported by the Helmholtz Alliance "Phys...

The depletion properties of silicon microstrip detectors with variable strip pitch

International Nuclear Information System (INIS)

Krizmanic, J.F.

1994-01-01

We have investigated the depletion properties of trapezoidal shaped silicon microstrip detectors which have variable strip pitch. Four types of detectors were examined: three detectors have constant strip width and a fourth has a varying strip width. The detectors are single sided with readout performed via p + strips. The depletion properties of the devices were measured using two different methods. The first used capacitance versus voltage measurements, while the second used a 1060 nm wavelength laser coupled to a single mode fiber with a mode field diameter less than 10 μm. The small laser spot size allowed for the depletion depth to be measured in a localized area of the detector. The laser induced charge on an electrode was measured as a function of reverse bias voltage using a sensitive charge preamplifier. The depletion voltages of the detectors demonstrate a strong dependence upon the ratio of strip width to strip pitch. Moreover, these measurements show that a large value of this ratio yields a lower depletion voltage and vice versa. (orig.)

Circular patch microstrip array antenna on NiCoAl ferrite substrate in C-band

International Nuclear Information System (INIS)

Kumar, Dheeraj; Pourush, P.K.S.

2010-01-01

The problem of a 4x4 circular disc array antenna (CDAA) printed on a uniaxially anisotropic ferrite (NiCoAl) substrate is treated. The effect of anisotropy on the resonant frequency of the antenna is investigated. Radiation and scattering characteristics of the antenna with normal magnetic bias field to the direction of wave propagation in the plane of ferrite are described. Calculated result for the radar cross section (RCS) of antenna presented, and it is shown that the peaks in the RCS can be moved with respect to angle of incidence by changing the magnetic bias field. This effect offers a way of minimizing the radar visibility of microstrip antennas and arrays. Results are obtained from cavity modal solutions for a circular patch antenna at its TM 11 mode.

Validation of new superheavy elements and IUPAC-IUPAP joint working group

International Nuclear Information System (INIS)

Jarlskog, Cecilia

2016-01-01

The great chemist Glenn Seaborg has written a delightful little book “Man-made Transuranium Elements”, published in 1963, in which he points out that: “The former basic criterion for the discovery of a new element – namely, chemical identification and separation from all previously-known elements – had to be changed in the case of lawrencium (element 103). This also may be true for elements beyond lawrencium.” Indeed this is what has happened. The elements with Z ≥ 103 are produced in nuclear reactions and are detected by counters. The detectors have undergone substantial refinement. For example one uses multiwire proportional chambers [for which George Charpak received the 1992 Nobel Prize in Physics] as well as solid state micro-strip detectors. In spite of this remarkable shift from chemistry to physics, the managerial staff of the International Union of Pure and Applied Chemistry (IUPAC) does not seem to be aware of what has been going on. The validation of superheavy elements should be done by physicists as the chemists lack the relevant competence as I will discuss here below. This article is about a collaboration between International Union of Pure and Applied Chemistry (IUPAC) and its sister organization International Union of Pure and Applied Physics (IUPAP), to deal with discovery of superheavy elements beyond Z = 112. I spent a great deal of time on this issue. In my opinion, the collaboration turned out to be a failure. For the sake of science, which should be our most important concern (and not politics), the rules for the future collaborations, if any, should be accurately defined and respected. The validation of new elements should be done by people who have the relevant competence – the physicists.

A new method for generating axially-symmetric and radially-polarized beams

International Nuclear Information System (INIS)

Niu Chunhui; Gu Benyuan; Dong Bizhen; Zhang Yan

2005-01-01

A scheme for generating axially-symmetric and radially-polarized beams is proposed by using two diffractive phase elements (DPEs) made of birefringent materials. The design of these two DPEs is based on the general theory of phase-retrieval of optical system in combination with an iterative algorithm. The first DPE is used for demultiplexing two orthogonally linearly-polarized light beams to produce diffractive patterns, and the second DPE is used for compensating the phase difference to obtain the desired radially-polarized beam

An integrated tunable isolator based on NiZn film fabricated by spin-spray plating

Science.gov (United States)

Guo, Rongdi; Lin, Hwaider; Shi, Wei; Gao, Yuan; Wang, Zhiguang; Sun, Nian Xiang; Yu, Zhong; Lan, Zhongwen

2018-05-01

An innovative type of tunable isolator with a planar comb-like microstrip transmission line, which generate circular polarization magnetic field, has been realized with polycrystalline NiZn ferrite thick films fabricated by spin-spray plating (SSP) process with thickness of 10μm. The phase compositions, microstructure, magnetic hysteresis loop, and ferromagnetic resonance (FMR) linewidth of NiZn ferrite thick films have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and electron spin resonance (ESR) spectrometer, respectively. The NiZn ferrite thick films possess 4800Gauss saturation magnetization and 190Oe FMR linewidth measured at X-band. With an in-plane dc magnetic bias perpendicular to the comb-like microstrip transmission line, the transmission direction of left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) were proved to be opposite. The non-reciprocal ferromagnetic resonance absorption leads to 11.6dB isolation and 5.78dB insertion loss at 17.57GHz with magnetic bias field of 3.5kOe. Furthermore, with external in-plane magnetic fields range from 0.5kOe to 3.5kOe, the central frequency was tuned from 5.63GHz to 17.57GHz. The state-of-the-art tunable isolator with a planar comb-like microstrip transmission line exhibit a great potential to be applied in different microwave components and radar system.

Solar Coronal Loops Associated with Small-scale Mixed Polarity Surface Magnetic Fields

International Nuclear Information System (INIS)

Chitta, L. P.; Peter, H.; Solanki, S. K.; Barthol, P.; Gandorfer, A.; Gizon, L.; Hirzberger, J.; Riethmüller, T. L.; Noort, M. van; Rodríguez, J. Blanco; Iniesta, J. C. Del Toro; Suárez, D. Orozco; Schmidt, W.; Pillet, V. Martínez; Knölker, M.

2017-01-01

How and where are coronal loops rooted in the solar lower atmosphere? The details of the magnetic environment and its evolution at the footpoints of coronal loops are crucial to understanding the processes of mass and energy supply to the solar corona. To address the above question, we use high-resolution line-of-sight magnetic field data from the Imaging Magnetograph eXperiment instrument on the Sunrise balloon-borne observatory and coronal observations from the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory of an emerging active region. We find that the coronal loops are often rooted at the locations with minor small-scale but persistent opposite-polarity magnetic elements very close to the larger dominant polarity. These opposite-polarity small-scale elements continually interact with the dominant polarity underlying the coronal loop through flux cancellation. At these locations we detect small inverse Y-shaped jets in chromospheric Ca ii H images obtained from the Sunrise Filter Imager during the flux cancellation. Our results indicate that magnetic flux cancellation and reconnection at the base of coronal loops due to mixed polarity fields might be a crucial feature for the supply of mass and energy into the corona.

Solar Coronal Loops Associated with Small-scale Mixed Polarity Surface Magnetic Fields

Energy Technology Data Exchange (ETDEWEB)

Chitta, L. P.; Peter, H.; Solanki, S. K.; Barthol, P.; Gandorfer, A.; Gizon, L.; Hirzberger, J.; Riethmüller, T. L.; Noort, M. van [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Rodríguez, J. Blanco [Grupo de Astronomía y Ciencias del Espacio, Universidad de Valencia, E-46980 Paterna, Valencia (Spain); Iniesta, J. C. Del Toro; Suárez, D. Orozco [Instituto de Astrofísica de Andalucía (CSIC), Apartado de Correos 3004, E-18080 Granada (Spain); Schmidt, W. [Kiepenheuer-Institut für Sonnenphysik, Schöneckstr. 6, D-79104 Freiburg (Germany); Pillet, V. Martínez [National Solar Observatory, 3665 Discovery Drive, Boulder, CO 80303 (United States); Knölker, M., E-mail: chitta@mps.mpg.de [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States)

2017-03-01

How and where are coronal loops rooted in the solar lower atmosphere? The details of the magnetic environment and its evolution at the footpoints of coronal loops are crucial to understanding the processes of mass and energy supply to the solar corona. To address the above question, we use high-resolution line-of-sight magnetic field data from the Imaging Magnetograph eXperiment instrument on the Sunrise balloon-borne observatory and coronal observations from the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory of an emerging active region. We find that the coronal loops are often rooted at the locations with minor small-scale but persistent opposite-polarity magnetic elements very close to the larger dominant polarity. These opposite-polarity small-scale elements continually interact with the dominant polarity underlying the coronal loop through flux cancellation. At these locations we detect small inverse Y-shaped jets in chromospheric Ca ii H images obtained from the Sunrise Filter Imager during the flux cancellation. Our results indicate that magnetic flux cancellation and reconnection at the base of coronal loops due to mixed polarity fields might be a crucial feature for the supply of mass and energy into the corona.

Beam splash effects on ATLAS silicon microstrip detectors evaluated using 1-w Nd YAG laser

CERN Document Server

Hara, K; Kohriki, T; Kuwano, T; Moorhead, G F; Terada, S; Unno, Y

2005-01-01

On an incident of accelerator beam loss, the tracking detector located close to the beam line is subjected to receive intensive radiation in a short period. We used a 1-W focused Nd: YAG laser and simulated the effects on the ATLAS microstrip detector. The laser corresponds to intensity of up to 1 multiplied by 109mips/pulse with a pulse width of about 10 ns. We observed breaks on Al strips on extreme conditions, depending on the laser intensity and bias voltage applied to the silicon sensor. The break can be interpreted as the oxide breakdown due to a large voltage locally created across the oxide by the intensive signal charges. The robustness of the Semiconductor Tracker (SCT) module including readout ASICs is also evaluated.

Attenuation characteristics of monolayer graphene by Pi-and T-networks modeling of multilayer microstrip line

Institute of Scientific and Technical Information of China (English)

Pulkit Sharma; Sumit Pratap Singh; Kamlesh Patel

2017-01-01

The impedances of Pi-and T-networks are obtained from the measured S-parameters of the multilayer microstrip line by modeling as an attenuator.The changes in impedances have been analyzed for the properties of various superstrates at the microwave ranges.With graphene on glass and graphene on quartz loadings,the impedances have increased and shifted towards lower frequency more in Pi-network than T-network modeling.This shift has become more prominent at higher frequency for the graphene on glass than graphene on quartz.A little increase in attenuation is found for graphene on glass or quartz than bare glass and quartz.The present study can be extended to obtain attenuation characteristic of any thin film by simple experimental method in the microwave frequencies.

Analysis of trace element compositions in adhesive cloth tapes using high-energy x-ray fluorescence spectrometer with three-dimensional polarization optics for forensic discrimination

International Nuclear Information System (INIS)

Goto, Akiko; Hokura, Akiko; Nakai, Izumi

2008-01-01

The forensic discrimination of adhesive cloth tapes often used in crimes was developed using a high-energy energy-dispersive X-ray fluorescence spectrometer with 3-dimensional polarization optics. The best measurement condition for discrimination of the tape was as follows: secondary targets, Rh and Al 2 O 3 ; measurement time, 300 s for Rh and 600 s for Al 2 O 3 ; 14 elements (Ca, Ti, Cr, Mn, Fe, Ni, Zn, Sr, Zr, Nb, Mo, Sb, Ba and Pb) were used for discrimination. It is found that the combined information of yarn density and the XRF peak intensity of the 14 elements successfully discriminated 29 out of 31 samples, of which 2 probably had the same origin. This technique is useful for forensic analysis, because it is nondestructive, rapid and easy. Therefore, it can be applied to actual forensic identification. (author)

2×1 Microstrip Patch Array Antenna with Harmonic Suppression Capability for Rectenna

Directory of Open Access Journals (Sweden)

Nur Aisyah Amir

2017-12-01

Full Text Available This paper is an extension of work originally presented in 2016 IEEE Asia-Pacific Conference on Applied Electromagnetics (APACE. A 2×1 microstrip patch array antenna integrated with photonic bandgap (PBG and stubs is designed and analyzed. The performance of the PBG and stubs structure are explained and analyzed in terms of the elimination of the resonance at the harmonic frequencies of the antenna. The proposed antenna is designed on FR-4 substrate with thickness of 1.6 mm and operated at 2.45 GHz frequency suitable for rectenna design application. From the simulated result, the first harmonic frequency (5.4 GHz, the second harmonic frequency (6.6 GHz and the third harmonic frequency (7.8 GHz are successfully suppressed. For instance, the radiation to the forward of the stubs-PBG antenna is suppressed at more than 15 dB at the second and third harmonic frequencies.

Cool Polar Bears: Dabbing on the Texture

Science.gov (United States)

O'Connell, Jean

2011-01-01

In this article, the author describes how her second-graders created their cool polar bears. The students used the elements of shape and texture to create the bears. They used Monet's technique of dabbing paint so as to give the bear some texture on his fur.

Calculation and construction of a beam-transport system for polarized electrons

International Nuclear Information System (INIS)

Marschke, G.

1987-09-01

In the framework of the ELSA-SAPHIR project a transfer channel between ELSA and the large-space detector SAPHIR was calculated and constructed. Existing optical elements were modified corresponding to their application and the missing racks constructed and ordered for fabrication. Furthermore the vacuum system was designed as the whole as well as in the single components. Starting from the architectonic conditions and the optics to be realized the coordinates of the elements were calculated as preconditions fo the geodetic measurements and calibrations. It was shown that both for a polarized and for an unpolarized electron beam an optic was realized corresponding to the requirements up to an energy of 3.5 GeV. Under the given conditions, the applied method of the rotation of the polarization vector, and the geometrical preconditions up to 3.0 GeV also an acceptable longitudinal polarization was reached. (orig./HSI) [de

Weak production of strangeness at threshold with polarization observables

International Nuclear Information System (INIS)

Baker, O.K.

2002-01-01

The differential cross section for the charged current electroweak reaction e → +p → ν → e +Λ → at threshold with polarization observables is presented. The form of the cross section at threshold for the reaction is simplified compared to higher energy. An expression is given for the invariant matrix element appropriate for the reaction when the incident electron is polarized, and the final state hyperon polarization is determined. The energy dependence of the resulting cross section is shown near threshold. Under the right kinematic conditions, there can be a sizeable enhancement in the cross section, making an experimental measurement of the weak axial-vector form factor feasible

Determination of trace elements in coffee beans by XRF spectrometer equipped with polarization optics and its application to identification of their production area

International Nuclear Information System (INIS)

Akamine, Takao; Otaka, Akiko; Nakai, Izumi; Hokura, Akiko; Ito, Yuji

2010-01-01

The production area of coffee beans becomes a brand name, which gives reputations for the products, which is related to the price. This leads to room for mislabeling the products by unscrupulous market dealers. A rapid and easy method for the analysis of trace-element composition of coffee beans, which could be a good indicator of their production area, was studied in the present work. Coffee beans of 6 different regions (Brazil, Colombia, Vietnam, Indonesia, Tanzania, Guatemala) were analyzed by using a highly sensitive X-ray fluorescence spectrometer with three dimensional polarization optics. The experimental conditions were optimized so as to analyze 6 elements (Mn, Fe, Ni, Rb, Sr, Ba) in coffee beans, and linear calibration curves were obtained for the quantitative analysis of those elements. The analytical results were used in principal-component analysis to classify the coffee beans according to the geographical origin, which results in a successful characterization of the 6 production areas. It is found that roasted beans can be used with the same criterion as their green beans. Consequently, a rapid and easy way for the characterization of the geographic origin of coffee beans has been established in this study. (author)

Optical asymmetric cryptography based on amplitude reconstruction of elliptically polarized light

Science.gov (United States)

Cai, Jianjun; Shen, Xueju; Lei, Ming

2017-11-01

We propose a novel optical asymmetric image encryption method based on amplitude reconstruction of elliptically polarized light, which is free from silhouette problem. The original image is analytically separated into two phase-only masks firstly, and then the two masks are encoded into amplitudes of the orthogonal polarization components of an elliptically polarized light. Finally, the elliptically polarized light propagates through a linear polarizer, and the output intensity distribution is recorded by a CCD camera to obtain the ciphertext. The whole encryption procedure could be implemented by using commonly used optical elements, and it combines diffusion process and confusion process. As a result, the proposed method achieves high robustness against iterative-algorithm-based attacks. Simulation results are presented to prove the validity of the proposed cryptography.

Stresses in Circular Plates with Rigid Elements

Science.gov (United States)

Velikanov, N. L.; Koryagin, S. I.; Sharkov, O. V.

2018-05-01

Calculations of residual stress fields are carried out by numerical and static methods, using the flat cross-section hypothesis. The failure of metal when exposed to residual stresses is, in most cases, brittle. The presence in the engineering structures of rigid elements often leads to the crack initiation and structure failure. This is due to the fact that rigid elements under the influence of external stresses are stress concentrators. In addition, if these elements are fixed by welding, the residual welding stresses can lead to an increase in stress concentration and, ultimately, to failure. The development of design schemes for such structures is a very urgent task for complex technical systems. To determine the stresses in a circular plate with a welded circular rigid insert under the influence of an external load, one can use the solution of the plane stress problem for annular plates in polar coordinates. The polar coordinates of the points are the polar radius and the polar angle, and the stress state is determined by normal radial stresses, tangential and shearing stresses. The use of the above mentioned design schemes, formulas, will allow more accurate determination of residual stresses in annular welded structures. This will help to establish the most likely directions of failure and take measures at the stages of designing, manufacturing and repairing engineering structures to prevent these failures. However, it must be taken into account that the external load, the presence of insulation can lead to a change in the residual stress field.

Generation of radio vortex beams with designable polarization using anisotropic frequency selective surface

Science.gov (United States)

Yang, Jin; Zhang, Cheng; Ma, Hui Feng; Zhao, Jie; Dai, Jun Yan; Yuan, Wei; Yang, Liu Xi; Cheng, Qiang; Cui, Tie Jun

2018-05-01

We propose a strategy to convert a linearly polarized wave from a single point source to an orbital angular momentum (OAM) wave by arbitrary polarization via an anisotropic frequency selective surface (FSS) in the microwave frequency. By tailoring the geometries of FSS elements, reflection-phases in x and y polarizations are engineered and encoded independently, which allows us to design the eventual polarization state of the generated OAM vortex beam by elaborately selecting individual coding sequences for each polarization. Two types of FSSs are designed and experimentally characterized to demonstrate the capability of OAM generation with circular and linear polarizations, respectively, showing excellent performance in a wide bandwidth from 14 to 16 GHz. This method provides opportunities for polarization multiplexing in microwave OAM communication systems.

Analysis of polarization introduced due to the telescope optics of the Thirty Meter Telescope

Science.gov (United States)

Anche, Ramya Manjunath; Sen, Asoke Kumar; Anupama, Gadiyara Chakrapani; Sankarasubramanian, Kasiviswanathan; Skidmore, Warren

2018-01-01

An analytical model has been developed to estimate the polarization effects, such as instrumental polarization (IP), crosstalk (CT), and depolarization, due to the optics of the Thirty Meter Telescope. These are estimated for the unvignetted field-of-view and the wavelengths of interest. The model estimates an IP of 1.26% and a CT of 44% at the Nasmyth focus of the telescope at the wavelength of 0.6 μm at field angle zero with the telescope pointing to zenith. Mueller matrices have been estimated for the primary, secondary, and Nasmyth mirrors. It is found that some of the Mueller matrix elements of the primary and secondary mirrors show a fourfold azimuthal antisymmetry, which indicates that the polarization at the Cassegrain focus is negligible. At the inclined Nasmyth mirror, there is no azimuthal antisymmetry in the matrix elements, and this results in nonzero values for IP and CT, which would negatively impact the polarization measurements at the telescope focus. The averaged Mueller matrix is estimated at the Nasmyth focus at different instrument ports and various zenith angles of the telescope. The variation in the Mueller matrix elements for different coatings is also estimated. The impact of this polarization effect on the science case requirements has been discussed. This analysis will help in achieving precise requirements for future instruments with polarimetric capability.

Targeting Cell Polarity Machinery to Exhaust Breast Cancer Stem Cells

Science.gov (United States)

2017-10-01

AWARD NUMBER: W81XWH-15-1-0644 TITLE: Targeting Cell Polarity Machinery to Exhaust Breast Cancer Stem Cells PRINCIPAL INVESTIGATOR: Chun-Ju...Targeting Cell Polarity Machinery to Exhaust Breast Cancer Stem Cells 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-1-0644 5c. PROGRAM ELEMENT...Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Cancer stem cells (CSCs), a cell population with acquired perpetuating self-renewal properties which

Simulation of the influence of line edge roughness on the performance of deep ultraviolet wire grid polarizers

Science.gov (United States)

Siefke, Thomas; Rojas Hurtado, Carol B.; Dickmann, Johannes; Heusinger, Martin; Kroker, Stefanie

2017-06-01

Controlling the polarization of light is crucial in numerous applications such as spectroscopy, ellipsometry, photo lithography or industrial vision. Polarization control can be realized by wire grid polarizers (WGPs), which are large aspect ratio, zero order gratings. These elements provide an anisotropic transmittance depending on the polarization direction of the incident light. WGPs' high attractiveness originates from their large free aperture, while simultaneously being extremely thin. Furthermore, these elements can be easily integrated into other nano-optical devices. Recently, such elements were successfully developed for applications down to the deep ultra violet spectral range. However, at shorter wavelengths the influence of roughness of the structures poses a severe limitation on the feasible optical performance. To tackle this problem, we numerically simulated the impact of line edge roughness on the polarization properties of WPGs. Therefore, we generated edge position data of rough grating lines by means of the Thorsos method and calculated the resulting optical response by finite difference time domain method. With this procedure the influence of standard deviation, correlation length, Hurst exponents and wavelength was investigated. We find that for standard deviations of 2.5 nm and 5.0 nm the polarization contrast is reduced by a factor of 3 and 7, respectively. The polarization contrast shows a minimum for intermediate correlation lengths, while virtually no impact of the Hurst exponent is observed. This is explained by several mechanisms occurring for different ratios between the spatial frequency of the roughness and the frequency of incident light. Our theoretical findings correlate well with experimental results we retrieved with measured roughness parameters of fabricated elements.

Circularly polarized antennas

CERN Document Server

Gao, Steven; Zhu, Fuguo

2013-01-01

This book presents a comprehensive insight into the design techniques for different types of CP antenna elements and arrays In this book, the authors address a broad range of topics on circularly polarized (CP) antennas. Firstly, it introduces to the reader basic principles, design techniques and characteristics of various types of CP antennas, such as CP patch antennas, CP helix antennas, quadrifilar helix antennas (QHA), printed quadrifilar helix antennas (PQHA), spiral antenna, CP slot antennas, CP dielectric resonator antennas, loop antennas, crossed dipoles, monopoles and CP horns. Adva

Detecting Changing Polarization Structures in Sagittarius A* with High Frequency VLBI

Science.gov (United States)

Fish, Vincent L.; Doeleman, Sheperd S.; Broderick, Avery E.; Loeb, Abraham; Rogers, Alan E. E.

2009-12-01

Sagittarius A* is the source of near infrared, X-ray, radio, and (sub)millimeter emission associated with the supermassive black hole at the Galactic Center. In the submillimeter regime, Sgr A* exhibits time-variable linear polarization on timescales corresponding to errors. Although the source-integrated linear polarization fraction in the models is typically only a few percent, the linear polarization fraction on small angular scales can be much higher, enabling the detection of changes in the polarimetric structure of Sgr A* on a wide variety of baselines. The shortest baselines track the source-integrated linear polarization fraction, while longer baselines are sensitive to polarization substructures that are beam-diluted by connected-element interferometry. The detection of periodic variability in source polarization should not be significantly affected even if instrumental polarization terms cannot be calibrated out. As more antennas are included in the (sub)millimeter-VLBI array, observations with full polarization will provide important new diagnostics to help disentangle intrinsic source polarization from Faraday rotation effects in the accretion and outflow region close to the black hole event horizon.

Wavelength conversion of a 128 Gbit/s DP-QPSK signal in a silicon polarization diversity circuit

DEFF Research Database (Denmark)

Vukovic, Dragana; Schroeder, Jochen; Ding, Yunhong

2014-01-01

Wavelength conversion of a 128 Gbit/s DP-QPSK signal is demonstrated using FWM in a polarization diversity circuit with silicon nanowires as nonlinear elements. Error-free performances are achieved with a negligible power penalty.......Wavelength conversion of a 128 Gbit/s DP-QPSK signal is demonstrated using FWM in a polarization diversity circuit with silicon nanowires as nonlinear elements. Error-free performances are achieved with a negligible power penalty....

ΔOSI: a prototype microstrip dosimeter for characterization of medical radiotherapy and radiosurgery systems

International Nuclear Information System (INIS)

Redondo-Fernandez, I.; Buttar, C.; Walsh, S.; Manolopoulos, S.; Homer, J.M.; Young, S.; Conway, J.

2006-01-01

As the technology for medical radiotherapy and radiosurgery evolves, there is a growing need for dosimeters capable of measuring dose distributions on-line with submillimeter spatial resolution, both for facility commissioning and patient-related quality assurance. We have designed and built a high spatial resolution dosimeter based on silicon micro-strip technology for characterization of small radiotherapy and radiosurgery fields. The aim is to provide relative dosimetry measurement with film-like spatial resolution and to be able to resolve the temporal evolution. Following the description of the prototypes, first beam test results of a 250 μm pitch, 128 channels prototype with X-rays in a clinical 6 MV accelerator are presented. The device demonstrated good dosimetric capabilities when compared to reference measurements made with ionization chambers and agrees with radiographic film in the steep dose gradient region produced by the collimator edge

A gas microstrip wide angle X-ray detector for application in synchrotron radiation experiments

CERN Document Server

Bateman, J E; Derbyshire, G E; Duxbury, D M; Lipp, J; Mir, J A; Simmons, J E; Spill, E J; Stephenson, R; Dobson, B R; Farrow, R C; Helsby, W I; Mutikainen, R; Suni, I

2002-01-01

The Gas Microstrip Detector has counting rate capabilities several orders of magnitude higher than conventional wire proportional counters while providing the same (or better) energy resolution for X-rays. In addition the geometric flexibility provided by the lithographic process combined with the self-supporting properties of the substrate offers many exciting possibilities for X-ray detectors, particularly for the demanding experiments carried out on Synchrotron Radiation Sources. Using experience obtained in designing detectors for Particle Physics we have developed a detector for Wide Angle X-ray Scattering studies. The detector has a fan geometry which makes possible a gas detector with high detection efficiency, sub-millimetre spatial resolution and good energy resolution over a wide range of X-ray energy. The detector is described together with results of experiments carried out at the Daresbury Laboratory Synchrotron Radiation Source.

The new BNL polarized negative ion source

International Nuclear Information System (INIS)

Hershcovitch, A.I.; Alessi, J.G.; DeVito, B.; Kponou, A.E.

1991-01-01

A new ground state source of negative hydrogen ions with polarized nuclei (rvec H - ) is being developed at BNL. Extensive developmental research has been aimed at improving each element of (rvec H - ) production: cold H degrees beam, spin selection and focusing magnets, and ionizer. These elements have recently been integrated into a source. A first test with the accommodator nozzle cooled only to liquid nitrogen temperatures resulted in 5 μA of H - . Tests at liquid helium temperatures are now beginning. 7 refs., 1 fig

Polarization measurement for internal polarized gaseous targets

International Nuclear Information System (INIS)

Ye Zhenyu; Ye Yunxiu; Lv Haijiang; Mao Yajun

2004-01-01

The authors present an introduction to internal polarized gaseous targets, polarization method, polarization measurement method and procedure. To get the total nuclear polarization of hydrogen atoms (including the polarization of the recombined hydrogen molecules) in the target cell, authors have measured the parameters relating to atomic polarization and polarized hydrogen atoms and molecules. The total polarization of the target during our measurement is P T =0.853 ± 0.036. (authors)

Reversible Shaping of Microwells by Polarized Light Irradiation

Directory of Open Access Journals (Sweden)

Federica Pirani

2017-01-01

Full Text Available In the last years, stimuli-responsive polymeric materials have attracted great interest, due to their low cost and ease of structuration over large areas combined with the possibility to actively manipulate their properties. In this work, we propose a polymeric pattern of soft-imprinted microwells containing azobenzene molecules. The shape of individual elements of the pattern can be controlled after fabrication by irradiation with properly polarized light. By taking advantage of the light responsivity of the azobenzene compound, we demonstrate the possibility to reversibly modulate a contraction-expansion of wells from an initial round shape to very narrow slits. We also show that the initial shape of the microconcavities can be restored by flipping the polarization by 90°. The possibility to reversibly control the final shape of individual elements of structured surfaces offers the opportunity to engineer surface properties dynamically, thus opening new perspectives for several applications.

A DOUBLE E SHAPED MICROSTRIP PATCH ANTENNA FOR MULTIBAND APPLICATIONS

Directory of Open Access Journals (Sweden)

Pristin K Mathew

2014-06-01

Full Text Available This paper presents a dual band Compact double E shaped Microstrip Patch antenna with enhanced gain for Worldwide Interoperability for Microwave Access (WI-MAX, Universal Mobile Telecommunication Systems (UMTS and Satellite applications. The modified E shaped patch antenna is designed using CADFEKO and the results of return loss, Voltage Standing Wave Ratio (VSWR, gain of the proposed antenna are compared with a conventional E shaped patch antenna. The results show that the double E shaped wideband patch antenna has an impedance bandwidth of 10.7 % with a return loss of -13.6dB, -12.4 dB, -12.1dB and -14.2dB at resonant frequencies of 1.96 GHz, 3.62 GHz, 5.76 GHz and 6.82 GHz, whereas a conventional E shaped patch antenna operates at 2.5 GHz, 3.4 GHz and 5.5 GHz with a return loss of -16 dB each and impedance bandwidth of 10.6 %. Both the antennas uses Coaxial Probe feeding technique and Flame Retardant 4 (FR-4 as the substrate material with a thickness of 2.87 mm. A parametric study has been done so as to understand the effect of each parameter to obtain a better performance and optimised results.

Dual band multi frequency rectangular patch microstrip antenna with flyswatter shaped slot for wireless systems

International Nuclear Information System (INIS)

Bhardwaj, Dheeraj; Saraswat, Shriti; Gulati, Gitansh; Shekhar, Snehanshu; Joshi, Kanika; Sharma, Komal

2016-01-01

In this paper a dual band planar antenna has been proposed for IEEE 802.16 Wi-MAX /IEEE 802.11 WLAN/4.9 GHz public safety applications. The antenna comprises a frequency bandwidth of 560MHz (3.37GHz-3.93GHz) for WLAN and WiMAX and 372MHz (4.82GHz-5.192GHz) for 4.9 GHz public safety applications and Radio astronomy services (4.8-4.94 GHz). The proposed antenna constitutes of a single microstrip patch reactively loaded with three identical steps positioned in a zig-zag manner towards the radiating edges of the patch. The coaxially fed patch antenna characteristics (radiation pattern, antenna gain, antenna directivity, current distribution, S_1_1) have been investigated. The antenna design is primarily focused on achieving a dual band operation.

Dual band multi frequency rectangular patch microstrip antenna with flyswatter shaped slot for wireless systems

Energy Technology Data Exchange (ETDEWEB)

Bhardwaj, Dheeraj, E-mail: dbhardwaj.bit@gmail.com [Department of Physics, BIT-Mesra-Jaipur Campus, Jaipur 302017 (India); Saraswat, Shriti, E-mail: saraswat.srishti@gmail.com; Gulati, Gitansh, E-mail: gitanshgulati@gmail.com; Shekhar, Snehanshu, E-mail: snehanshushekhar.bit@gmail.com; Joshi, Kanika, E-mail: kanika.karesh@gmail.com [Department of Electronics & Communication, BIT-Mesra-Jaipur Campus, Jaipur 302017 (India); Sharma, Komal, E-mail: kbhardwaj18@gmail.com [Department of Physics, Swami Keshvanand Institute of Technology, Jaipur 302017 (India)

2016-03-09

In this paper a dual band planar antenna has been proposed for IEEE 802.16 Wi-MAX /IEEE 802.11 WLAN/4.9 GHz public safety applications. The antenna comprises a frequency bandwidth of 560MHz (3.37GHz-3.93GHz) for WLAN and WiMAX and 372MHz (4.82GHz-5.192GHz) for 4.9 GHz public safety applications and Radio astronomy services (4.8-4.94 GHz). The proposed antenna constitutes of a single microstrip patch reactively loaded with three identical steps positioned in a zig-zag manner towards the radiating edges of the patch. The coaxially fed patch antenna characteristics (radiation pattern, antenna gain, antenna directivity, current distribution, S{sub 11}) have been investigated. The antenna design is primarily focused on achieving a dual band operation.

Dual band multi frequency rectangular patch microstrip antenna with flyswatter shaped slot for wireless systems

Science.gov (United States)

Bhardwaj, Dheeraj; Saraswat, Shriti; Gulati, Gitansh; Shekhar, Snehanshu; Joshi, Kanika; Sharma, Komal

2016-03-01

In this paper a dual band planar antenna has been proposed for IEEE 802.16 Wi-MAX /IEEE 802.11 WLAN/4.9 GHz public safety applications. The antenna comprises a frequency bandwidth of 560MHz (3.37GHz-3.93GHz) for WLAN and WiMAX and 372MHz (4.82GHz-5.192GHz) for 4.9 GHz public safety applications and Radio astronomy services (4.8-4.94 GHz). The proposed antenna constitutes of a single microstrip patch reactively loaded with three identical steps positioned in a zig-zag manner towards the radiating edges of the patch. The coaxially fed patch antenna characteristics (radiation pattern, antenna gain, antenna directivity, current distribution, S11) have been investigated. The antenna design is primarily focused on achieving a dual band operation.

Bistability and hysteresis in the emergence of pulses in microstrip Gunn-diode circuits

Energy Technology Data Exchange (ETDEWEB)

Yurchenko, V. B., E-mail: v.yurchenko@nuim.ie [O. Ya. Usikov Institute for Radiophysics and Electronics, National Academy of Sciences of Ukraine, 12 Proskura St., Kharkiv 61085 (Ukraine); Electrical and Electronic Engineering Department, Gazi University, Celal Bayar Bulvari, Ankara 06570 (Turkey); Yurchenko, L. V. [O. Ya. Usikov Institute for Radiophysics and Electronics, National Academy of Sciences of Ukraine, 12 Proskura St., Kharkiv 61085 (Ukraine)

2014-12-15

We develop time-domain simulations of microwave and THz radiation sources built as arrays of active devices when the radiation wavelength is small as compared to spacing between electronic components. We pursue an approach when the system is represented by equations with time-delay feedback that could generate chaos and other forms of complicated dynamics. The approach simplifies simulations of ultra-wideband effects and exceeds capabilities of frequency-domain methods. As a model case, we simulated a microstrip circuit with Gunn diode and a remote resonator emitting the radiation towards infinity. We observed the emergence of either the continuous waves or the trains of high-frequency pulses depending on the bias conditions. We found bistability and hysteresis in the onset of different oscillation modes that depends on the way of driving the bias voltage into the domain of instability of the given system. The results would allow one to improve the design of THz radiation sources with time-delay coupling between components.

Cylinder and metal grating polarization beam splitter

Science.gov (United States)

Yang, Junbo; Xu, Suzhi

2017-08-01

We propose a novel and compact metal grating polarization beam splitter (PBS) based on its different reflected and transmitted orders. The metal grating exhibits a broadband high reflectivity and polarization dependence. The rigorous coupled wave analysis is used to calculate the reflectivity and the transmitting spectra and optimize the structure parameters to realize the broadband PBS. The finite-element method is used to calculate the field distribution. The characteristics of the broadband high reflectivity, transmitting and the polarization dependence are investigated including wavelength, period, refractive index and the radius of circle grating. When grating period d = 400 nm, incident wavelength λ = 441 nm, incident angle θ = 60° and radius of circle d/5, then the zeroth reflection order R0 = 0.35 and the transmission zeroth order T0 = 0.08 for TE polarization, however, T0 = 0.34 and R0 = 0.01 for TM mode. The simple fabrication method involves only single etch step and good compatibility with complementary metal oxide semiconductor technology. PBS designed here is particularly suited for optical communication and optical information processing.

Thermococcus kodakarensis modulates its polar membrane lipids and elemental composition according to growth stage and phosphate availability

Directory of Open Access Journals (Sweden)

Travis B. Meador

2014-01-01

Full Text Available We observed significant changes in the elemental and intact polar lipid (IPL composition of the archaeon Thermococcus kodakarensis (KOD1 in response to growth stage and phosphorus supply. Reducing the amount of organic supplements and phosphate in growth media resulted in significant decreases in cell size and cellular quotas of carbon (C, nitrogen (N, and phosphorus (P, which coincided with significant increases in cellular IPL quota and IPLs comprising multiple P atoms and hexose moieties. Relatively more cellular P was stored as IPLs in P-limited cells (2-8% compared to control cells (< 0.8%. We also identified a specific IPL biomarker containing a phosphatidyl-N-acetylhexoseamine headgroup that was relatively enriched during rapid cell division. These observations serve as empirical evidence of IPL adaptations in Archaea that will help to interpret the distribution of these biomarkers in natural systems. The reported cell quotas of C, N, and P represent the first such data for a specific archaeon and suggest that thermophiles are C-rich compared to the cell carbon-to-volume relationship reported for planktonic bacteria.

An Ultra-wideband and Polarization-independent Metasurface for RCS Reduction.

Science.gov (United States)

Su, Pei; Zhao, Yongjiu; Jia, Shengli; Shi, Wenwen; Wang, Hongli

2016-02-11

In this paper, an ultra-wideband and polarization-independent metasurface for radar cross section (RCS) reduction is proposed. The unit cell of the metasurface operates in a linear cross-polarization scheme in a broad band. The phase and amplitude of cross-polarized reflection can be separately controlled by its geometry and rotation angle. Based on the diffuse reflection theory, a 3-bit coding metasurface is designed to reduce the RCS in an ultra-wide band. The wideband property of the metasurface benefits from the wideband cross polarization conversion and flexible phase modulation. In addition, the polarization-independent feature of the metasurface is achieved by tailoring the rotation angle of each element. Both the simulated and measured results demonstrate that the proposed metasurface can reduce the RCS significantly in an ultra-wide frequency band for both normal and oblique incidences, which makes it promising in the applications such as electromagnetic cloaking.

"Cul-de-sac" microstrip resonators for high-speed integrated optical commutator switches

Science.gov (United States)

Jaeger, Nicolas A.; Chen, Mingche

1993-04-01

A novel microstrip resonator structure for use with integrated Y-branch optical modulators fabricated in Ti:LiNbO3 is proposed. The legs of the structure are intended to act as the electrodes of the modulator, with light being directed into each of the output waveguides of the Y-branch on alternate half-cycles of the standing wave excited in the resonator; forming an optical commutator switch. Such resonators having Al2O3 substrates were designed, fabricated, and tested. Measurements on one such resonator, operating at 7.12 GHz and having an unloaded quality factor of 123, indicating that 50 V should develop across the ends of its legs for 35 mW dissipated power; the corresponding values, from the model used to design the resonator, were 179, 50 V,and 24 mW, respectively. Using the model it is shown that a similar resonator fabricated on LiNbO3 should be able to develop about 50 V for 100 mW dissipated power at 15 GHz.

Signals from fluorescent materials on the surface of silicon micro-strip sensors

CERN Document Server

Sperlich, Dennis; The ATLAS collaboration

2018-01-01

For the High-Luminosity Upgrade of the Large Hadron Collider at CERN, the ATLAS Inner Detector will be replaced with a new, all-silicon tracker (ITk). In order to minimise the amount of material in the ITk, circuit boards with readout electronics will be glued onto the active area of the sensor. Several adhesives, investigated to be used for the construction of detector modules, were found to become fluorescent when exposed to UV light. These adhesives could become a light source in the high-radiation environment of the ATLAS detector. The effect of fluorescent material covering the sensor surface in a high-radiation environment has been studied for a silicon micro-strip sensor using a micro-focused X-ray beam. By positioning the beam parallel to the sensor surfave and pointing it both inside the sensor and above the sensor surface inside the deposited glue, the sensor responses from direct hits and fluorescence can be compared with high precision. This contribution presents a setup to study the susceptibilit...

Development of microstrip gas chamber and application to imaging gamma-ray detector

International Nuclear Information System (INIS)

Tanimori, T.; Minami, S.; Nagae, T.; Takahashi, T.; Miyagi, T.

1992-07-01

We have developed Microstrip Gas Chamber (MSGC) by using Multi-Chip technology which enables high-density assembly of bare LSI chips on a silicon board. Our MSGC was operated steadily with ∼ 10 3 gain more than one week. An energy resolution of 15% (FWHM) for 5.9 keV X-ray of 55 Fe was obtained. With very thin polyimide substrate of 16 μm thickness, two interesting phenomena were observed; one is a strong dependence of gains on the back plane potential, and the other is little time variation of gains. New type of MSGC with a guarding mask of a thin polyimide layer on the cathode edges has been examined to reduce incidental electrical discharges between anode and cathode strips. Furthermore, new approach to reduce the resistivity of the substrate has been examined. By these approaches, the stability of the high gain operation of ∼ 10 4 has been drastically improved. In addition, we discuss the possibility of the application of MSGC to the coded mask X-ray imaging detector for astrophysics. (author)

Beta decay of polarized nuclei and the decay asymmetry of 8Li

International Nuclear Information System (INIS)

Bigelow, R.; Freedman, S.J.; Napolitano, J.; Quin, P.A.

1985-01-01

Under certain conditions, it is possible to produce vector-polarized radioactive nuclei in reactions with a polarized projectile and an unpolarized target. Using the intense polarized beams at the University of Wisconsin, the authors have begun a program to study the weak interaction through the beta decay of polarized nuclei produced in this way. Such experiments bear on tests of CVC in light nuclei, sensitive searches for second-class weak currents, and measurements of the weak vector-coupling constant. One may also deduce the values of certain matrix elements. Our effort is presently centering on a study of the energy dependence of the beta-decay asymmetry of 8 Li

TX-RX isolation method based on polarization diversity, spatial diversity and TX beamforming

DEFF Research Database (Denmark)

Foroozanfard, Ehsan; Carvalho, Elisabeth De; Pedersen, Gert F.

2016-01-01

In this paper, the feasibility of an antenna isolation technique based on null-steer beamforming, polarization diversity and spatial diversity is investigated. The proposed system consists of six patch antennas which are fed by a feeding network to obtain a null-steer beamformer. To achieve spatial...... diversity, antenna elements are located on two layers, facing in a different direction. Moreover, the antenna elements in two layers use different polarization. The measured results of the antenna system present a high TX-RX isolation in the order of 70 dB which shows the feasibility of such a system...

SPIN-POLARIZED PHOTOCURRENT THROUGH QUANTUM DOT PHOTODETECTOR

Directory of Open Access Journals (Sweden)

Nguyen Van Hieu

2017-11-01

Full Text Available The theory of the photocurrent through the photodetector based on a two-level semiconductor quantum dot (QD is presented. The analytical expressions of the matrix elements of the electronic transitions generated by the absorption of the circularly polarized photons are derived in the lowest order of the perturbation theory with respect to the electron tunneling interaction as well as the electron-photon interaction. From these expressions the mechanism of the generation of the spin-polarized of electrons in the photocurrent is evident. It follows that the photodetector based on the two-level semiconductor QD can be used as the model of a source of highly spinpolarized electrons.

ATLAS irradiation studies of n-in-n and p-in-n silicon microstrip detectors

CERN Document Server

Allport, P P; Buttar, C M; Carter, J; Drage, L M; Ferrère, D; Morgan, D; Riedler, P; Robinson, D

1999-01-01

Prior to the module production of the ATLAS silicon microstrip tracker for the barrel and the forward wheels, the characterisation of full-size prototype silicon detectors after radiation to fluences corresponding to 10 years of ATLAS operation is required. The behaviour of p-in-n and n-in-n detectors produced by several manufacturers before and after irradiation to a fluence of 3*10/sup 14/ protons/cm/sup 2/ at the CERN PS facility is discussed. This article summarises some recent results from the ATLAS SCT collaboration. The measurements of leakage current, full depletion voltage, signal-to-noise ratio and charge collection efficiency are presented. Despite the better efficiency performance of n-in-n detectors below depletion, the collaboration chose the p-in-n technology due to its simpler and less costly production since good charge collection efficiencies were achieved at the desired maximum bias voltage. (14 refs).

Design of beam deflector, splitters, wave plates and metalens using photonic elements with dielectric metasurface

Science.gov (United States)

Zhang, Qing; Li, Maozhong; Liao, Tingdi; Cui, Xudong

2018-03-01

Under the trend of miniaturization and reduction of system complexity, conventional bulky photonic elements are expected to be replaced by new compact and ultrathin dielectric metasurface elements. In this letter, we propose an αTiO2 dielectric metasurface (DM) platform that could be exploited to design high efficiency wave-front control devices at visible wavelength. Combining with fundamental principles and full wave simulations (Lumerical FDTD 3D solver ®), we successfully realize four DM devices, such as anomalous beam deflectors, polarization insensitive metalens, wave plates and polarization beam splitters. All these devices can achieve high transmission efficiencies (larger than 80%). Among them, the anomalous refraction beam deflectors can bend light propagation to any desired directions; the polarization insensitive metalens maintains diffraction limited focus (focal spot as small as 0.67 λ); the quarter-wave and half-wave plates have broadband working wavelengths from 550 to 1000 nm; and the polarization beam splitter can split an arbitrarily polarized incident beam into two orthogonally polarized beams, the TM components is deflected to the right side, and the TE components is deflected to the left side. These devices may find applications in the areas of imaging, polarization control, spectroscopy, and on-chip optoelectronic systems etc., and our studies may richen the design of all-dielectric optical elements at visible wavelength.

Ultra-high tunable liquid crystal-plasmonic photonic crystal fiber polarization filter.

Science.gov (United States)

Hameed, Mohamed Farhat O; Heikal, A M; Younis, B M; Abdelrazzak, Maher; Obayya, S S A

2015-03-23

A novel ultra-high tunable photonic crystal fiber (PCF) polarization filter is proposed and analyzed using finite element method. The suggested design has a central hole infiltrated with a nematic liquid crystal (NLC) that offers high tunability with temperature and external electric field. Moreover, the PCF is selectively filled with metal wires into cladding air holes. Results show that the resonance losses and wavelengths are different in x and y polarized directions depending on the rotation angle φ of the NLC. The reported filter of compact device length 0.5 mm can achieve 600 dB / cm resonance losses at φ = 90° for x-polarized mode at communication wavelength of 1300 mm with low losses of 0.00751 dB / cm for y-polarized mode. However, resonance losses of 157.71 dB / cm at φ = 0° can be achieved for y-polarized mode at the same wavelength with low losses of 0.092 dB / cm for x-polarized mode.

Design,construction and commissioning of a cylinder of double-sided silicon micro-strips detectors for the Star experiment at RHIC

International Nuclear Information System (INIS)

Guedon, M.

2005-05-01

This study has been performed in the frame of quark gluon plasma physics research in the STAR experiment at RHIC. It deals with the design, the construction and the commissioning of a barrel of silicon-strip detectors (SSD). Added to the Silicon Vertex Tracker (SVT) of the STAR detector, it extends the capabilities of track reconstruction for charged particles emitted in ultra-relativistic heavy-ion collisions. It also contributes to the general study of the quark-gluon plasma production undertaken at STAR. The SSD is a cylinder of 1 m long and of 23 cm radius, and it is composed of 320 compact identical modules. Each module includes one double-sided silicon micro-strip detector, 12 readout chips ALICE 128C, 12 TAB ribbons, 2 COSTAR control chips and 2 hybrids supporting all the components. The document explains why the SSD is an important and relevant element, and justifies the technological choices as well as their validation by in-beam characterization. All component functionalities, characteristics and test procedures are presented. The data and test results are stored in a database for tracing purpose. Component and module production is described. Two parallel studies have been performed, analysed and described. One on the temperature dependence of the module performances and the other one on the optimal adjustments of the analogue blocks inside the ALICE 128C chip. The SSD installation on the RHIC site as well as the commissioning are presented together with the first data takings. (author)

Variable-delay Polarization Modulators for the CLASS Telescope

Science.gov (United States)

Harrington, Kathleen; Ali, A.; Amiri, M.; Appel, J. W.; Araujo, D.; Bennett, C. L.; Boone, F.; Chan, M.; Cho, H.; Chuss, D. T.; Colazo, F.; Crowe, E.; Denis, K.; Dünner, R.; Eimer, J.; Essinger-Hileman, T.; Gothe, D.; Halpern, M.; Hilton, G.; Hinshaw, G. F.; Huang, C.; Irwin, K.; Jones, G.; Karakla, J.; Kogut, A. J.; Larson, D.; Limon, M.; Lowry, L.; Marriage, T.; Mehrle, N.; Miller, A. D.; Miller, N.; Mirel, P.; Moseley, S. H.; Novak, G.; Reintsema, C.; Rostem, K.; Stevenson, T.; Towner, D.; U-Yen, K.; Wagner, E.; Watts, D.; Wollack, E.; Xu, Z.; Zeng, L.

2014-01-01

The challenges of measuring faint polarized signals at microwave wavelengths have motivated the development of rapid polarization modulators. One scalable technique, called a Variable-delay Polarization Modulator (VPM), consists of a stationary wire array in front of a movable mirror. The mirror motion creates a changing phase difference between the polarization modes parallel and orthogonal to the wire array. The Cosmology Large Angular Scale Surveyor (CLASS) will use a VPM as the first optical element in a telescope array that will search for the signature of inflation through the “B-mode” pattern in the polarization of the cosmic microwave background. In the CLASS VPMs, parallel transport of the mirror is maintained by a voice-coil actuated flexure system which will translate the mirror in a repeatable manner while holding tight parallelism constraints with respect to the wire array. The wire array will use 51 μm diameter copper-plated tungsten wire with 160 μm pitch over a 60 cm clear aperture. We present the status of the construction and testing of the mirror transport mechanism and wire arrays for the CLASS VPMs.

The Correlation Characteristics of Polarization Backscattering Matrix of Dense Chaff Clouds

Directory of Open Access Journals (Sweden)

B. Tang

2018-04-01

Full Text Available This paper studied the correlation characteristics of the polarization backscattering matrix of the dense chaff cloud with uniform orientation and location distributions in circular symmetry region. Based on the theoretical analysis and numerical experiments, the correlation coefficients of the four elements in the polarization backscattering matrix are obtained, and the results indicate that the cross to co-polar correlation coefficient is still zero; and that the sum of the co-polar cross-correlation coefficient and the two times of linear depolarization ratio equals one. The results are beneficial for better understanding of the backscattering characteristics of dense chaff clouds, and are useful in the application of jamming recognition in radar electronic warfare. Numerical experiments are performed by using the method of moments.

Polar bears at risk

Energy Technology Data Exchange (ETDEWEB)

Norris, S.; Rosentrater, L.; Eid, P.M. [WWF International Arctic Programme, Oslo (Norway)

2002-05-01

Polar bears, the world's largest terrestrial carnivore, spend much of their lives on the arctic sea ice. This is where they hunt and move between feeding, denning, and resting areas. The world population, estimated at 22,000 bears, is made up of 20 relatively distinct populations varying in size from a few hundred to a few thousand animals. About 60 per cent of all polar bears are found in Canada. In general, the status of this species is stable, although there are pronounced differences between populations. Reductions in the extent and thickness of sea ice has lead the IUCN Polar Bear Specialist Group to describe climate change as one of the major threats facing polar bears today. Though the long-term effects of climate change will vary in different areas of the Arctic, impacts on the condition and reproductive success of polar bears and their prey are likely to be negative. Longer ice-free periods resulting from earlier break-up of sea ice in the spring and later formation in the fall is already impacting polar bears in the southern portions of their range. In Canada's Hudson Bay, for example, bears hunt on the ice through the winter and into early summer, after which the ice melts completely, forcing bears ashore to fast on stored fat until freeze-up in the fall. The time bears have on the ice to hunt and build up their body condition is cut short when the ice melts early. Studies from Hudson Bay show that for every week earlier that ice break-up occurs, bears will come ashore 10 kg lighter and in poorer condition. It is likely that populations of polar bears dividing their time between land and sea will be severely reduced and local extinctions may occur as greenhouse gas emissions continue to rise and sea ice melts. Expected changes in regional weather patterns will also impact polar bears. Rain in the late winter can cause maternity dens to collapse before females and cubs have departed, thus exposing occupants to the elements and to predators. Such

Antimatter and Dark Matter Search in Space: BESS-Polar Results

Science.gov (United States)

Mitchell, John W.; Yamamoto, Akira

2009-01-01

The apex of the Balloon-borne Experiment with a Superconducting Spectrometer program was reached with the Antarctic flight of BESS-Polar II, during the 2007-2008 Austral Summer, that obtained 24.5 days of data on over 4.7 billion cosmic-ray events. The US-Japan BESS Collaboration uses elementary particle measurements to study the early Universe and provides fundamental data on the spectra of light cosmic-ray elements and isotopes. BESS measures the energy spectra of cosmic-ray antiprotons to investigate signatures of possible exotic sources, such as dark-matter candidates, and searches for heavier anti-nuclei that might reach Earth from antimatter domains formed during symmetry breaking processes in the early Universe. Since 1993, BESS has carried out eleven high-latitude balloon flights, two of long duration, that together have defined the study of antiprotons below about 4 GeV, provided standard references for light element and isotope spectra, and set the most sensitive limits on the existence of anti-deuterons and anti-helium, The BESS-Polar II flight took place at Solar Minimum, when the sensitivity of the low-energy antiproton measurements to a primary source is greatest. The rich BESS-Polar II dataset more than doubles the combined data from all earlier BESS flights and has 10-20 times the statistics of BESS data from the previous Solar Minimum. Here, we summarize the scientific results of BESS program, focusing on the results obtained using data from the long-duration flights of BESS-Polar I (2004) and BESS-Polar II.

Spectral element method for vector radiative transfer equation

International Nuclear Information System (INIS)

Zhao, J.M.; Liu, L.H.; Hsu, P.-F.; Tan, J.Y.

2010-01-01

A spectral element method (SEM) is developed to solve polarized radiative transfer in multidimensional participating medium. The angular discretization is based on the discrete-ordinates approach, and the spatial discretization is conducted by spectral element approach. Chebyshev polynomial is used to build basis function on each element. Four various test problems are taken as examples to verify the performance of the SEM. The effectiveness of the SEM is demonstrated. The h and the p convergence characteristics of the SEM are studied. The convergence rate of p-refinement follows the exponential decay trend and is superior to that of h-refinement. The accuracy and efficiency of the higher order approximation in the SEM is well demonstrated for the solution of the VRTE. The predicted angular distribution of brightness temperature and Stokes vector by the SEM agree very well with the benchmark solutions in references. Numerical results show that the SEM is accurate, flexible and effective to solve multidimensional polarized radiative transfer problems.

Spin characteristics of ion beams during the motion of electromagnetic elements

Science.gov (United States)

Zaika, N. I.; Magal, M. I.

The matrix method for description of the polarization components for ions moving through different electromagnetic systems: dipole magnets, cycle accelerators, quadrupole lenses, solenoids, wine filters, and electrostatic mirrors is developed in the paper. The expressions for elements of the transportation matrixes for the above-mentioned systems taking account of the projective trajectories are obtained. The program, TRANSPIN, for calculation of the beam polarization components after motion by ions of arbitrary number of electromagnetic elements along any possible trajectory is presented. The calculation results made for some of transportation lines for the isochronous cyclotron U-240 are discussed (trajectories for the ion motion were calculated by CERN-program TRANSPORT). The conditions for decrease of the polarization component dispersion because of difference between trajectories of the particles motion are also defined.

Excellent polarization-independent reflector based on guided mode resonance effect

International Nuclear Information System (INIS)

Xu Cheng; Xu Lin-Min; Qiang Ying-Huai; Zhu Ya-Bo; Liu Jiong-Tian; Ma Jian-Yong

2011-01-01

A broad band polarization-independent reflector working in the telecommunication C+L band is proposed using the guided mode resonance effect of a periodic surface relief element deposited by a layer of silicon medium. It is shown that this structure can provide high reflection (R > 99.5%) and wide angular bandwidth (θ ≈ 20°, R > 98%) for both TE and TM polarizations over a wide spectrum band 1.5 μm∼1.6 μm. Furthermore, it is found by rigorous coupled wave analysis that the polarization-independent reflector proposed here is tolerant of a deviation of grating thickness, which makes it very easy to fabricate in experiments. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Efficient analysis for nonlinear microwave characteristics of high-power HTS thin film microstrip resonators

Energy Technology Data Exchange (ETDEWEB)

Kedar, Ashutosh [RADL Division, Electronics and Radar Development Establishment, C V Raman Nagar, Bangalore-560093 (India); Kataria, N D [National Physical Laboratory, New Delhi (India)

2005-08-01

This paper investigates the nonlinear effects of high-T{sub c} superconducting (HTS) thin film in high-power applications. A nonlinear model for complex surface impedance has been proposed for the efficient analysis of the nonlinearity of HTS thin films. Further, using the developed model, analysis of HTS-MSR has been done using the spectral domain method (SDM). The SDM formulation has been modified to account for finite conductivity and thickness of HTS films by incorporating a complex resistive boundary condition. The results have been validated with the experiments performed with microstrip resonators (MSRs) based on YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) thin films made by a laser ablation technique on LaAlO{sub 3} substrates, characterized for their characteristics, namely, resonant frequency and quality factor measured as a function of temperature and input RF power. A close agreement between the theoretical and measured results has been achieved validating the analysis.

Efficient analysis for nonlinear microwave characteristics of high-power HTS thin film microstrip resonators

International Nuclear Information System (INIS)

Kedar, Ashutosh; Kataria, N D

2005-01-01

This paper investigates the nonlinear effects of high-T c superconducting (HTS) thin film in high-power applications. A nonlinear model for complex surface impedance has been proposed for the efficient analysis of the nonlinearity of HTS thin films. Further, using the developed model, analysis of HTS-MSR has been done using the spectral domain method (SDM). The SDM formulation has been modified to account for finite conductivity and thickness of HTS films by incorporating a complex resistive boundary condition. The results have been validated with the experiments performed with microstrip resonators (MSRs) based on YBa 2 Cu 3 O 7-x (YBCO) thin films made by a laser ablation technique on LaAlO 3 substrates, characterized for their characteristics, namely, resonant frequency and quality factor measured as a function of temperature and input RF power. A close agreement between the theoretical and measured results has been achieved validating the analysis

Design of single-polarization wavelength splitter based on photonic crystal fiber.

Science.gov (United States)

Zhang, Shanshan; Zhang, Weigang; Geng, Pengcheng; Li, Xiaolan; Ruan, Juan

2011-12-20

A new single-polarization wavelength splitter based on the photonic crystal fiber (PCF) has been proposed. The full-vector finite-element method (FEM) is applied to analyze the single-polarization single-mode guiding properties. Splitting of two different wavelengths is realized by adjusting the structural parameters. The semi-vector three-dimensional beam propagation method is employed to confirm the wavelength splitting characteristics of the PCF. Numerical simulations show that the wavelengths of 1.3 μm and 1.55 μm are split for a fiber length of 10.7 mm with single-polarization guiding in each core. The crosstalk between the two cores is low over appreciable optical bandwidths.

Study of microstrip gas chambers for CMS experiment and measurement of the W boson mass in the DELPHI experiment

International Nuclear Information System (INIS)

Ripp-Baudot, I.

2004-06-01

In this document the author describes 3 fields of his research activities: first, the development and validation tests of micro-strip gas chambers for the CMS experiment; secondly, the measurements of the W boson mass and width by analysing the events: e + e - → W + W - → qq-bar qq-bar whose data have been collected in the DELPHI experiment (at the LEP-2 accelerator); and thirdly, the tagging of b-jets that is an essential tool for the study of the top quark. The last chapter is dedicated to what is expected from LHC experiments concerning the properties of the quark top: mass, spin, production and decay channels

Simulation and Verification of Tip-Induced Polarization During Kelvin Probe Force Microscopy Measurements on Film Capacitors

DEFF Research Database (Denmark)

Nielsen, Dennis Achton; Popok, Vladimir; Pedersen, Kjeld

2017-01-01

have developed a physics-based finite element model of KPFM measurements on dielectrics in order to investigate the impact of tip-induced polarization. The model is compared with experiments on film capacitors, where it is found that tip-induced polarization is a significant contributor...

A time digitizer for the microstrip detectors of the PANDA MVD

Energy Technology Data Exchange (ETDEWEB)

Riccardi, Alberto; Brinkmann, Kai-Thomas; Di Pietro, Valentino [II. Physikalisches Institut, Justus-Liebig-Universitaet Giessen (Germany); Garbolino, Sara; Rivetti, Angelo; Rolo, Manuel [INFN Sezione di Torino, Torino (Italy); Collaboration: PANDA-Collaboration

2015-07-01

In nuclear detectors the information on the energy of the particle is usually obtained by measuring the amplitude of the signal delivered by the sensor. The low voltage power supply used in modern deep submicron technologies constrain the maximum dynamic range of the ADC. Still, the energy information can be obtained with time-based techniques, in which the energy is associated with the duration of the signal through the Time over Threshold method. This work is focused on the PANDA Micro Vertex Detector and explores the possibility of applying a time-based readout approach for the microstrip sensors. In PANDA, the strip system must cope with hit rates up to 50 kHz per channel. Therefore, the front-end output must be relatively short, this implies that the clock resolution is not enough to measure the signal duration, so it is necessary to use a Time to Digital Converter. The front-end and the TDC structure are designed in a 0.11μm CMOS process. The TDC chosen is based on an analog clock interpolator because it combines good time resolution with a fairly simple implementation and low power consumption. In the presentation an overview of the analog part of the PASTA (PANDA strip ASIC) is presented.

A suitable material for the substrate of micro-strip gas chamber

International Nuclear Information System (INIS)

Zhang Minglong; Xia Yiben; Wang Linjun; Zhang Weili

2004-01-01

Micro-strip Gas Chamber (MSGC) used as a position sensitive detector has perfect performances in the detection of nuclear irradiations. However, it encounters a severe problem, that is, positive charge accumulation which can be avoided by reducing the surface resistivity of insulating substrate. So, diamond-like carbon (DLC) film is coated on D263 glass to modify its electrical properties as substrate for MSGC. Raman spectroscopy demonstrates that DLC film is of sp 3 (σ bounding) and sp 2 bonding (π bonding), and therefore it is a type of electronically conducting material. It also reveals that the film deposited on D263 glass possesses very large of sp 3 content and consequently is a high quality DLC film. I-V plots indicate that samples with DLC film enjoy very steady and suitable resistivities in the range of 10 9 -10 12 Ω·cm. C-F characteristics also show that samples coated by DLC film have low and stable capacitance with frequency. These excellent performances of the new material, DLC film/D263 glass, meet the optimum requirements of MSGC. DLC film/D263 glass used as the substrate of MSGC should effectively avoid the charge pile-up effect and substrate instability and then improve its performances

Theoretical and experimental investigation of a rectenna element for microwave power transmission

Science.gov (United States)

Mcspadden, James O.; Yoo, Taewhan; Chang, Kai

1992-01-01

A microstrip measurement system has been designed to analyze packaged GaAs Schottky barrier diodes under small and large signal conditions. The nonlinear equivalent circuit parameters of the diode are determined using a small signal test method that analyzes the diode's scattering parameters at various bias levels. The experimental results of a 2.45 GHz diode are verified using a nonlinear circuit simulation program based on a multireflection algorithm. A 35 GHz rectenna has been built using a microstrip patch antenna and Ka-band mixer diode. The measured efficiency was 29 percent at 120 mW input power. A frequency selective surface is designed using an equivalent circuit model to reduce the second harmonic radiations for a 2.45 GHz rectenna. Theoretical results are found to be in fairly good agreement with experiments.

Polarization splitter based on interference effects in all-solid photonic crystal fibers.

Science.gov (United States)

Mao, Dong; Guan, Chunying; Yuan, Libo

2010-07-01

We propose a novel kind of polarization splitter in all-solid photonic crystal fibers based on the mode interference effects. Both the full-vector finite-element method and the semi-vector three-dimensional beam propagation method are employed to design and analyze the characteristics of the splitter. Numerical simulations show that x-polarized and y-polarized modes are split entirely along with 6.8 mm long propagation. An extinction ratio of more than 20 dB and a crosstalk of less than -20 dB are obtained within the wavelength range of 1.541-1.556 microm. The extinction ratio and the crosstalk at 1.55 microm are 28.9 and -29.0 dB for x polarization, while the extinction ratio and the crosstalk at 1.55 microm are 29.9 and -29.8 dB for y polarization, respectively.

Spin characteristics of ion beams during the motion of electromagnetic elements

International Nuclear Information System (INIS)

Zaika, N.I.; Magal', M.I.

1991-01-01

The matrix method for description of the polarization components for ions moving through different electromagnetic systems: dipole magnets, cycle accelerators, quadrupole lenses, solenoids, wine filters, electrostatic mirrors is developed in the paper. The expressions for elements of the transportation matrixes for the above-mentioned systems taking account of the projective trajectories are obtained. The programme TRANSPIN for calculation of the beam polarization components after motion by ions of arbitrary number of electromagnetic elements along any possible trajectory is worked out. The calculation results made for some of transportation lines for the isochronous cyclotron U-240 are discussed (trajectories for the ion motion were calculated by CERN-programme TRANSPORT). The conditions for decrease of the polarization component dispersion because of difference between trajectories of the particles motion are also defined. 6 refs.; 2 figs.; 4 tables. (author)

Construction of the new silicon microstrips tracker for the Phase-II ATLAS detector

CERN Document Server

Liang, Zhijun; The ATLAS collaboration

2018-01-01

The inner detector of the present ATLAS detector has been designed and developed to function in the environment of the present Large Hadron Collider (LHC). At the next-generation tracking detector proposed for the High Luminosity LHC (HL-LHC), the so-called ATLAS Phase-II Upgrade, the particle densities and radiation levels will be higher by as much as a factor of ten. The new detectors must be faster, they need to be more highly segmented, and covering more area. They also need to be more resistant to radiation, and they require much greater power delivery to the front-end systems. For those reasons, the inner tracker of the ATLAS detector must be redesigned and rebuilt completely. The design of the ATLAS Upgrade inner tracker (ITk) has already been defined. It consists of several layers of silicon particle detectors. The innermost layers will be composed of silicon pixel sensors, and the outer layers will consist of silicon microstrip sensors. This paper will focus on the latest research and development act...

Characterisation of an inhomogeneously irradiated microstrip detector using a fine spot infrared laser

CERN Document Server

Casse, G; Bowcock, T J V; Greenall, A; Phillips, JP; Turner, PR; Wright, V

2001-01-01

A prototype silicon microstrip detector for the LHCb vertex locator (VELO) has been partially irradiated using a 24 GeV/c proton beam at the CERN-PS accelerator. The detector possesses a radial strip geometry designed to measure the azimuthal coordinate (Phi) of tracks within the VELO. The peak fluence received by the detector was measured to be 4.6×10 14 p/cm 2 though the non-uniform nature of the exposure left part of the detector unirradiated. The inhomogeneous irradiation introduced a damage profile in the detector approximating to that expected in the VELO. High irradiation gradients are important to study as they can modify the electric field within the silicon. Of special interest are changes in the component of the electric field parallel to the strip plane but perpendicular to the strips which lead to systematic shifts in the reconstructed cluster position. If these (flux and position dependent) shifts are sufficiently large they could contribute to a degraded spatial resolution of the detector. In ...

Silicon microstrip detector development in the Institute for High Energy Physics Zeuthen, GDR

International Nuclear Information System (INIS)

Lange, W.; Nowak, W.D.; Truetzschler, K.

1990-01-01

This paper reports that in regard of the growing interest to study short living particles demanding for high resolution vertex detectors the authors started to build Si microstrip detectors. The first detector generation was characterized by a small area of silicon and a readout via printed circuit board fan out. Now they can assemble detectors with larger areas and VLSI readout. A special cleanroom has been built. Equipment and tools necessary are available. Silicon wafers and thick film hybrid circuits are fabricated under collaboration by the GDR industry. Applications of their detectors were several test-runs at CERN to calibrate the L3 time expansion chamber (TEC) and the L3 muon chambers. A 10-layer telescope is designed now and it is planned to calibrate a high resolution scintillation fiber target. Future applications will be high resolution vertex detectors, e.g. L3 upgrading (LEP, CERN) or KEDR (VEPP-5, Novosibirsk). Further investigations will concern AC coupled strip detectors (single and double sided) and pixel and/or pad detectors

Design Studies of Ultra-Wideband Microstrip Antennas with a Small Capacitive Feed

Directory of Open Access Journals (Sweden)

Veeresh G. Kasabegoudar

2007-01-01

Full Text Available The design of an ultra-wideband microstrip patch antenna with a small coplanar capacitive feed strip is presented. The proposed rectangular patch antenna provides an impedance bandwidth of nearly 50%, and has stable radiation patterns for almost all frequencies in the operational band. Results presented here show that such wide bandwidths are also possible for triangular and semiellipse geometries with a similar feed arrangement. The proposed feed is a very small strip placed very close to the radiator on a substrate above the ground plane. Shape of the feed strip can also be different, so long as the area is not changed. Experimental results agree with the simulated results. Effects of key design parameters such as the air gap between the substrate and the ground plane, the distance between radiator patch and feed strip, and the dimensions of the feed strip on the input characteristics of the antenna have been investigated and discussed. As demonstrated here, the proposed antenna can be redesigned for any frequency in the L-, S-, C-, or X-band. A design criterion for the air gap has been empirically obtained to enable maximum antenna bandwidth for all these operational frequencies.

Polarization and Spin Alignment in Multihadronic Z0 Decays

CERN Document Server

Kress, Thomas

2001-01-01

The large statistics of millions of hadronic Z0 decays, accumulated by the four LEP experiments between 1989 and 1995, allowed for detailed investigations of the fragmentation process. Inclusive Lambda_b baryons and Lambda hyperons at intermediate and high momentum have been found to show longitudinal polarization. This may be related to the primary quark and antiquark polarization and the hadronization mechanism which produces the leading baryons. Helicity density-matrix elements have been measured for a variety of vector mesons produced inclusively in hadronic Z0 decays. The diagonal elements of some of the light mesons and the D*+- show a preference for a helicity-zero state if the meson carries a large fraction of the available energy. The mechanism which produces such spin alignment in the non-perturbative hadronization of the primary partons to the vector mesons is so far unexplained. For the B* the results are consistent with no spin alignment, which is expected in a picture based on HQET. For some mes...

Novel calibration system with sparse wires for CMB polarization receivers

International Nuclear Information System (INIS)

Tajima, O.; Nguyen, H.; Bischoff, C.; Brizius, A.; Buder, I.; Kusaka, A.

2011-01-01

B-modes in the cosmic microwave background (CMB) polarization is a smoking gun signature of the inflationary universe. To achieve better sensitivity to this faint signal, CMB polarization experiments aim to maximize the number of detector elements, resulting in a large focal plane receiver. Detector calibration of the polarization response becomes essential. It is extremely useful to be able to calibrate 'simultaneously' all detectors on the large focal plane. We developed a novel calibration system that rotates a large 'sparse' grid of metal wires, in front of and fully covering the field of view of the focal plane receiver. Polarized radiation is created via the reflection of ambient temperature from the wire surface. Since the detector has a finite beam size, the observed signal is smeared according to the beam property. The resulting smeared polarized radiation has a reasonable intensity (a few Kelvin or less) compared to the sky temperature (∼10 K observing condition). The system played a successful role for receiver calibration of QUIET, a CMB polarization experiment located in the Atacama desert in Chile. The successful performance revealed that this system is applicable to other experiments based on different technologies, e.g. TES bolometers.

Dual-Polarized Cross Bowtie Dipole for 3G and LTE Applications

Directory of Open Access Journals (Sweden)

Zhi-Ya Zhang

2013-01-01

Full Text Available A dual-polarized cross bowtie dipole element with parasitical circular patch and vertical metal cylinders for base station antennas is presented. A pair of orthogonal cross bowtie dipoles, with a reflector ground plane, is used to obtain the two linear polarizations. Besides two inverted L-shaped feed strips and two shorted feed baluns, parasitical circular patch is introduced to improve the impendence bandwidth and vertical metal cylinders are employed to decrease the lateral dimensions of the antenna. A wideband impedance characteristic of about 45.6% for VSWR ≤ 1.5 (+45° polarization and VSWR ≤ 1.5 (−45° polarization ranging from 1.76 to 2.80 GHz is obtained. Moreover, the stable peak gain, unidirectional radiation patterns, high isolation between the two orthogonal polarizations, and low cross-polarization over the whole operating band are also achieved. The proposed antenna is very suitable for potential base station applications in mobile communication such as TD-SCDMA, WCDMA, and CDMA2000 and LTE applications.

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.

Interferometric sensor based on the polarization-maintaining fibers

Science.gov (United States)

Cubik, Jakub; Kepak, Stanislav; Doricak, Jan; Vašinek, Vladimir; Liner, Andrej; Papes, Martin

2012-01-01

The interferometers composed of optical fibers are due to its high sensitivity capable of to measure various influences affecting the fiber. These influences may be bending or different sorts of fiber deformations, vibration, temperature, etc. In this case the vibration is the measured quantity, which is evaluated by analyzing the interference fringes representing changes in the fiber. Was used a Mach-Zehnder interferometer composed of the polarization maintaining elements. The polarization maintaining elements were used because of high sensitivity to polarization state inside the interferometer. The light was splitted into the two optical paths, where the first one is the reference fiber and it is separated from the actual phenomenon, and the second one is measuring fiber, which is directly exposed to vibration transmission from the underlying surface. The light source was narrowband DFB laser serating at a wavelength of 1550nm and as a detector an InGaAs PIN photodiode were used in this measurement. The electrical signal from the photodiode was amplified and fed into the measuring card. On the incoming signal the FFT was applied, which performs the transformation into the frequency domain and the results were further evaluated by software. We were evaluating the characteristic frequencies and their amplitude ratios. The frequency responses are unique for a given phenomenon, thus it is possible to identify recurring events by the characteristic frequencies and their amplitude ratios. The frequency range was limited by the properties of the used speaker, by the frequency characteristics of the filter in the amplifier and used resonant element. For the experiment evaluation the repeated impact of the various spherical objects on the surface board was performed and measured. The stability of amplitude and frequency and also the frequency range was verified in this measurement.