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Sample records for dielectric resonator antenna

  1. Radiation Characteristics Enhancement of Dielectric Resonator Antenna Using Solid/Discrete Dielectric Lenses

    Directory of Open Access Journals (Sweden)

    H. A. E. Malhat

    2015-02-01

    Full Text Available The radiation characteristics of the dielectric resonator antennas (DRA is enhanced using different types of solid and discrete dielectric lenses. One of these approaches is by loading the DRA with planar superstrate, spherical lens, or by discrete lens (transmitarray. The dimensions and dielectric constant of each lens are optimized to maximize the gain of the DRA. A comparison between the radiations characteristics of the DRA loaded with different lenses are introduced. The design of the dielectric transmitarray depends on optimizing the heights of the dielectric material of the unit cell. The optimized transmitarray achieves 7 dBi extra gain over the single DRA with preserving the circular polarization. The proposed antenna is suitable for various applications that need high gain and focused antenna beam.

  2. High Dielectric Low Loss Transparent Glass Material Based Dielectric Resonator Antenna with Wide Bandwidth Operation

    Science.gov (United States)

    Mehmood, Arshad; Zheng, Yuliang; Braun, Hubertus; Hovhannisyan, Martun; Letz, Martin; Jakoby, Rolf

    2015-01-01

    This paper presents the application of new high permittivity and low loss glass material for antennas. This glass material is transparent. A very simple rectangular dielectric resonator antenna is designed first with a simple microstrip feeding line. In order to widen the bandwidth, the feed of the design is modified by forming a T-shaped feeding. This new design enhanced the bandwidth range to cover the WLAN 5 GHz band completely. The dielectric resonator antenna cut into precise dimensions is placed on the modified microstrip feed line. The design is simple and easy to manufacture and also very compact in size of only 36 × 28 mm. A -10 dB impedance bandwidth of 18% has been achieved, which covers the frequency range from 5.15 GHz to 5.95 GHz. Simulations of the measured return loss and radiation patterns are presented and discussed.

  3. 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...

  4. Design of microwave dielectric resonator antenna using MZTO-CSTO composite

    Czech Academy of Sciences Publication Activity Database

    Rajput, S.S.; Keshri, S.; Gupta, V.R.; Gupta, N.; Bovtun, Viktor; Petzelt, Jan

    2012-01-01

    Roč. 38, č. 3 (2012), s. 2355-2362 ISSN 0272-8842 Institutional research plan: CEZ:AV0Z10100520 Keywords : composites * permittivity * dielectric resonator antenna * radiation pattern Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.789, year: 2012

  5. Micromachined On-Chip Dielectric Resonator Antenna Operating at 60 GHz

    KAUST Repository

    Sallam, Mai

    2015-06-01

    This paper presents a novel cylindrical Dielectric Resonator Antenna (DRA) suitable for millimeter-wave on-chip systems. The antenna was fabricated from a single high resistivity silicon wafer via micromachining technology. The new antenna was characterized using HFSS and experimentally with good agreement been found between the simulations and experiment. The proposed DRA has good radiation characteristics, where its gain and radiation efficiency are 7 dBi and 79.35%, respectively. These properties are reasonably constant over the working frequency bandwidth of the antenna. The return loss bandwidth was 2.23 GHz, which corresponds to 3.78% around 60 GHz. The antenna was primarily a broadside radiator with -15 dB cross polarization level.

  6. Higher order mode of a microstripline fed cylindrical dielectric resonator antenna

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, A. V. Praveen, E-mail: praveen.kumar@pilani.bits-pilani.ac.in [Department of Electrical and Electronics Engineering, BITS Pilani, Pilani, Rajasthan-333 031 (India)

    2016-03-09

    A microstrip transmission line can be used to excite the broadside radiating mode of a cylindrical dielectric resonator antenna (CDRA). The same is found to excite considerably well a higher order mode (HOM) as well. However unlike the broadside mode, the higher order mode gives distorted radiation pattern which makes this mode less useful for practical applications. The cause of distortion in the HOM radiation and the dependence of HOM coupling on the microstrip feed line are explored using HFSS simulations.

  7. Triband Omnidirectional Circularly Polarized Dielectric Resonator Antenna with Top-Loaded Alford Loop

    Directory of Open Access Journals (Sweden)

    Chunxia Cheng

    2014-01-01

    Full Text Available A triband omnidirectional circularly polarized dielectric resonator antenna with a top-loaded modified Alford loop for GSM, WLAN, and WiMAX applications is proposed. Fed by an axial probe, the DRA (dielectric resonator antenna radiates like a vertically polarized electric monopole. The top-loaded modified Alford loop provides an equivalent horizontally polarized magnetic dipole mode at triband. Omnidirectional CP (circular polarized fields can be obtained when the two orthogonally polarized fields are equal in amplitude with phase quadrature. The antenna has been successfully simulated, fabricated, and measured. The experimental and numerical results exhibit that the antenna can obtain usable CP bandwidths of 1.925–1.955 GHz, 2.36–2.48 GHz, and 3.502–3.53 GHz with return loss larger than 10 dB and axial ratio less than 3 dB. In addition, over the three bands, the antenna obtains very good omnidirectional CP radiation patterns in the azimuth plane. Moreover, an average CP gain in the azimuth plane of 1.2, 1.6, and −1.5 dBic for the lower, middle, and upper bands has been obtained.

  8. Throughput Measurement of a Dual-Band MIMO Rectangular Dielectric Resonator Antenna for LTE Applications.

    Science.gov (United States)

    Nasir, Jamal; Jamaluddin, Mohd Haizal; Ahmad Khan, Aftab; Kamarudin, Muhammad Ramlee; Yen, Bruce Leow Chee; Owais, Owais

    2017-01-13

    An L-shaped dual-band multiple-input multiple-output (MIMO) rectangular dielectric resonator antenna (RDRA) for long term evolution (LTE) applications is proposed. The presented antenna can transmit and receive information independently using fundamental TE 111 and higher order TE 121 modes of the DRA. TE 111 degenerate mode covers LTE band 2 (1.85-1.99 GHz), 3 (1.71-1.88 GHz), and 9 (1.7499-1.7849 GHz) at f r = 1.8 GHz whereas TE 121 covers LTE band 7 (2.5-2.69 GHz) at f r = 2.6 GHz, respectively. An efficient design method has been used to reduce mutual coupling between ports by changing the effective permittivity values of DRA by introducing a cylindrical air-gap at an optimal position in the dielectric resonator. This air-gap along with matching strips at the corners of the dielectric resonator keeps the isolation at a value more than 17 dB at both the bands. The diversity performance has also been evaluated by calculating the envelope correlation coefficient, diversity gain, and mean effective gain of the proposed design. MIMO performance has been evaluated by measuring the throughput of the proposed MIMO antenna. Experimental results successfully validate the presented design methodology in this work.

  9. Lattices of dielectric resonators

    CERN Document Server

    Trubin, Alexander

    2016-01-01

    This book provides the analytical theory of complex systems composed of a large number of high-Q dielectric resonators. Spherical and cylindrical dielectric resonators with inferior and also whispering gallery oscillations allocated in various lattices are considered. A new approach to S-matrix parameter calculations based on perturbation theory of Maxwell equations, developed for a number of high-Q dielectric bodies, is introduced. All physical relationships are obtained in analytical form and are suitable for further computations. Essential attention is given to a new unified formalism of the description of scattering processes. The general scattering task for coupled eigen oscillations of the whole system of dielectric resonators is described. The equations for the  expansion coefficients are explained in an applicable way. The temporal Green functions for the dielectric resonator are presented. The scattering process of short pulses in dielectric filter structures, dielectric antennas  and lattices of d...

  10. A Series-Fed Linear Substrate-Integrated Dielectric Resonator Antenna Array for Millimeter-Wave Applications

    Directory of Open Access Journals (Sweden)

    Ke Gong

    2018-01-01

    Full Text Available A series-fed linear substrate-integrated dielectric resonator antenna array (SIDRAA is presented for millimeter-wave applications, in which the substrate-integrated dielectric resonator antenna (SIDRA elements and the feeding structure can be codesigned and fabricated using the same planar process. A prototype 4 × 1 SIDRAA is designed at Ka-band and fabricated with a two-layer printed circuit board (PCB technology. Four SIDRAs are implemented in the Rogers RT6010 substrate using the perforation technique and fed by a compact substrate-integrated waveguide (SIW through four longitudinal coupling slots within the Rogers RT5880 substrate. The return loss, radiation patterns, and antenna gain were experimentally studied, and good agreement between the measured and simulated results is observed. The SIDRAA example provides a bandwidth of about 10% around 34.5 GHz for 10 dB return loss and stable broadside radiation patterns with the peak gain of 10.5–11.5 dBi across the band.

  11. Dielectric optical antenna thermal emitters and metamaterials

    Science.gov (United States)

    Schuller, Jonathan Aaron

    Optical antennas are critical components in nanophotonics research due to their unparalleled ability to concentrate electromagnetic energy into nanoscale volumes. Researchers typically construct such antennas from wavelength-size metallic structures. However, recent research has begun to exploit the scattering resonances of high-permittivity particles to realize all-dielectric optical antennas, emitters, and metamaterials. In this thesis, we experimentally and theoretically characterize the resonant modes of subwavelength rod-shaped dielectric particles and demonstrate their use in negative index metamaterials and novel infrared light emitters. At mid-infrared frequencies, Silicon Carbide (SiC) is an ideal system for studying the behavior of dielectric optical antennas. At frequencies below the TO phonon resonance, SiC behaves like a dielectric with very large refractive index. Using infrared spectroscopy and analytical Mie calculations we show that individual rod-shaped SiC particles exhibit a multitude of resonant modes. Detailed investigations of these SiC optical antennas reveal a wealth of new physics and applications. We discuss the distinct electromagnetic field profile for each mode, and demonstrate that two of the dielectric-type Mie resonances can be combined in a particle array to form a negative index metamaterial. We further show that these particles can serve as "broadcasting" antennas. Using a custom-built thermal emission microscope we collect emissivity spectra from single SiC particles at elevated temperatures, highlighting their use as subwavelength resonant light emitters. Finally, we derive and verify a variety of general analytical results applicable to all cylindrical dielectric antennas.

  12. Dielectric Optical Antenna Emitters and Metamaterials

    Science.gov (United States)

    Schuller, Jon

    2009-03-01

    Optical antennas are critical components in nanophotonics research due to their unparalleled ability to concentrate electromagnetic energy into nanoscale volumes. Researchers typically construct such antennas from wavelength-size metallic structures. However, recent research has begun to exploit the scattering resonances of high-permittivity particles to realize all-dielectric optical antennas, emitters, and metamaterials. In this talk, we experimentally and theoretically characterize the resonant modes of subwavelength rod-shaped dielectric particles and demonstrate their use in negative index metamaterials and novel infrared light emitters. At mid-infrared frequencies, Silicon Carbide (SiC) is an ideal system for studying the behavior of dielectric optical antennas. At frequencies below the TO phonon resonance, SiC behaves like a dielectric with very large refractive index. Using infrared spectroscopy and analytical Mie calculations we show that individual rod-shaped SiC particles exhibit a multitude of resonant modes. Detailed investigations of these SiC optical antennas reveal a wealth of new physics and applications. We discuss the distinct electromagnetic field profile for each mode, and demonstrate that two of the dielectric-type Mie resonances can be combined in a particle array to form a negative index metamaterial [1]. We further show that these particles can serve as ``broadcasting'' antennas. Using a custom-built thermal emission microscope we collect emissivity spectra from single SiC particles at elevated temperatures, highlighting their use as subwavelength resonant light emitters. Finally, we derive and verify a variety of general analytical results applicable to all cylindrical dielectric antennas and discuss extensions of the demonstrated concepts to different materials systems and frequency regimes. [1] J.A. Schuller, et al., Phys. Rev. Lett. 99, 107401 (2007)

  13. Design and Fabrication of High Gain Multi-element Multi-segment Quarter-sector Cylindrical Dielectric Resonator Antenna

    Science.gov (United States)

    Ranjan, Pinku; Gangwar, Ravi Kumar

    2017-12-01

    A novel design and analysis of quarter cylindrical dielectric resonator antenna (q-CDRA) with multi-element and multi-segment (MEMS) approach has been presented. The MEMS q-CDRA has been designed by splitting four identical quarters from a solid cylinder and then multi-segmentation approach has been utilized to design q-CDRA. The proposed antenna has been designed for enhancement in bandwidth as well as for high gain. For bandwidth enhancement, multi-segmentation method has been explained for the selection of dielectric constant of materials. The performance of the proposed MEMS q-CDRA has been demonstrated with design guideline of MEMS approach. To validate the antenna performance, three segments q-CDRA has been fabricated and analyzed practically. The simulated results have been in good agreement with measured one. The MEMS q-CDRA has wide impedance bandwidth (|S11|≤-10 dB) of 133.8 % with monopole-like radiation pattern. The proposed MEMS q-CDRA has been operating at TM01δ mode with the measured gain of 6.65 dBi and minimum gain of 4.5 dBi in entire operating frequency band (5.1-13.7 GHz). The proposed MEMS q-CDRA may find appropriate applications in WiMAX and WLAN band.

  14. Experimental and Simulation Investigation of Tri-Sector Cylindrical Dielectric Resonator Antenna in composite forms for Wireless Applications

    Science.gov (United States)

    Ranjan, Pinku; Gangwar, Ravi Kumar

    2016-11-01

    In this article, a tri-sector cylindrical dielectric resonator antenna (t-CDRA) has been introduced by splitting CDRA into three uniform sectors and all three uniform sectors are packed together in a compact way on a metallic ground plane. A coaxial probe feed is used to excite the proposed composite t-CDRA at the center position. Multi-segmentation approach has been applied for further improvement in bandwidth of proposed t-CDRA. The proposed composite t-CDRA has been designed using HFSS simulation software and analyzed using theoretical analysis. The prototype of t-CDRA, three elements t-CDRA and three elements dual segment t-CDRA has been fabricated for measurement. The input characteristics, near field, far field distribution of the proposed t-CDRAs have been studied through HFSS simulation software and their results are compared with corresponding experimental results. Proposed segmented t-CDRA has wide impedance bandwidth (|S11|≤-10 dB) of 85 % with monopole-like radiation pattern. The peak gain of segmented t-CDRA has 5.1 dBi with 98.5 % radiation efficiency. The proposed segmented t-CDRA may find suitable applications in 5.0 GHz WLAN and WiMAX band.

  15. Trends of microwave dielectric materials for antenna application

    International Nuclear Information System (INIS)

    Sulong, T. A. T.; Osman, R. A. M.; Idris, M. S.

    2016-01-01

    Rapid development of a modern microwave communication system requires a high quality microwave dielectric ceramic material to be used as mobile and satellite communication. High permittivity of dielectric ceramics leads to fabrication of compact device for electronic components. Dielectric ceramics which used for microwave applications required three important parameters such as high or appropriate permittivity (ε_r), high quality factor (Q _f ≥ 5000 GH z) and good temperature coefficient of resonant frequency (τ_f). This paper review of various dielectric ceramic materials used as microwave dielectric materials and related parameters for antenna applications.

  16. Trends of microwave dielectric materials for antenna application

    Energy Technology Data Exchange (ETDEWEB)

    Sulong, T. A. T., E-mail: tuanamirahtuansulong@gmail.com; Osman, R. A. M., E-mail: rozana@unimap.edu.my [School of Microelectronic Engineering, Universiti Malaysia Perlis, Pauh Putra Campus, 02600 Arau, Perlis (Malaysia); Idris, M. S., E-mail: sobri@unimap.edu.my [Sustainable Engineering Research Cluster, School of Material Engineering, Universiti Malaysia Perlis, Blok B, Taman Pertiwi Indah, Seriab, 01000 Kangar, Perlis (Malaysia)

    2016-07-19

    Rapid development of a modern microwave communication system requires a high quality microwave dielectric ceramic material to be used as mobile and satellite communication. High permittivity of dielectric ceramics leads to fabrication of compact device for electronic components. Dielectric ceramics which used for microwave applications required three important parameters such as high or appropriate permittivity (ε{sub r}), high quality factor (Q {sub f} ≥ 5000 GH z) and good temperature coefficient of resonant frequency (τ{sub f}). This paper review of various dielectric ceramic materials used as microwave dielectric materials and related parameters for antenna applications.

  17. Investigations on perturbations of microwave dielectric resonator thermometer

    International Nuclear Information System (INIS)

    Yu, Lili; Zhang, Guangming; Fernicola, V; Lu, Jinchuan

    2017-01-01

    Investigations of antenna probe length, antenna-dielectric distance, cavity filling and humidity on microwave resonator thermometer with respect to Q , spurious mode depression, coupling strength, accuracy, shock resistance or sensitivity were carried out in order to improve the dielectric resonator thermometer performance. Significant improvement of Q and depression of spurious mode coupling were obtained when the antenna length was reduced. It also turns out that the Q and spurious mode coupling strength vary with the distance between dielectric and antenna pin, as well under appropriate antenna length. Filling the cavity with nitrogen increases coupling strength but decrease frequency-temperature sensitivity compared to a vacuum-pumped cavity. Besides, preliminary results on the microwave resonator sensitivity to air humidity were obtained. (technical note)

  18. Wide-scan dielectric dome antenna with reduced profile

    NARCIS (Netherlands)

    Gandini, E.; Silvestri, F.; Benini, A.; Gerini, G.; Martini, E.; Maci, S.; Viganò, M.C.; Toso, G.; Monni, S.

    2017-01-01

    In this contribution, a dielectric dome antenna design in Ka-band is presented. The dome antenna is based on the combination of a phased array and a dielectric lens. The goal of the combination of these structures is to enlarge the field of view of the antenna. In particular, the array is considered

  19. Dielectric image line groove antennas for millimeterwaves

    Science.gov (United States)

    Solbach, K.; Wolff, I.

    Grooves in the ground plane of dielectric image lines are proposed as a new radiating structure. A figure is included showing the proposed groove structure as a discontinuity in a dielectric image line. A wave incident on the dielectric image line is partly reflected by the discontinuity, partly transmitted across the groove, and partly radiated into space above the line. In a travelling-wave antenna, a number of grooves are arranged below a dielectric guide, with spacings around one guide wavelength to produce a beam in the upper half space. A prescribed aperture distribution can be effected by tapering the series radiation resistance of the grooves. This can be done by adjusting the depths of the grooves with a constant width or by varying the widths of the grooves with a constant depth. Attention is also given to circular grooves. Here, the widths of the holes are chosen so that they can be considered as waveguides operating far below the cut-off frequency of the fundamental circular waveguide mode.

  20. Resonator graphene microfluidic antenna (RGMA) for blood glucose detection

    Science.gov (United States)

    Jizat, Noorlindawaty Md.; Mohamad, Su Natasha; Ishak, Muhammad Ikman

    2017-09-01

    Graphene is capable of highly sensitive analyte detection due to its nanoscale nature. Here we show a resonator graphene microfluidic antenna (RGMA) is used to detect the dielectric properties of aqueous glucose solution which represent the glucose level in blood. Simulation verified the high sensitivity of proposed RGMA made with aqueous glucose solutions at different concentrations. The RGMA yielded a sensor sensitivity of 0.1882GHz/mgml-1 as plotted from the slope of the linear fit from the result averages in S11 and S21 parameter, respectively. This results indicate that the proposed resonator antenna achieves high sensitivity and linear to the changes of glucose concentration.

  1. Resonant-bar gravitational radiation antennas

    International Nuclear Information System (INIS)

    Blair, D.G.

    1987-01-01

    This paper reviews the concept of gravitational radiation, and describes the worldwide research programme for the development of high-sensitivity resonant-bar antennas which are aimed at detecting gravitational radiation from astrophysical sources. (author)

  2. Resonant double loop antenna development at ORNL

    International Nuclear Information System (INIS)

    Taylor, D.J.; Baity, F.W.; Brown, R.A.; Bryan, W.E.; Fadnek, A.; Hoffman, D.J.; King, J.F.; Livesey, R.L.; McIlwain, R.L.

    1988-01-01

    As part of the development of ion cyclotron resonant heating (ICRH) systems for fusion research, Oak Ridge National Laboratory (ORNL) has built resonant double loop (RDL) antennas for the Tokamak Fusion Test Reactor (TFTR) (Princeton Plasma Physics Laboratory, Princeton, NJ, US) and Tore Supra (Centre d'Etudes Nucleaire, Cadarache, France). Each antenna has been designed to deliver 4 MW of power. The electrical circuit and the mechanical philosophy employed are the same for both antennas, but different operating environments lead to substantial differences in the designs of specific components. A description and a comparison of the technologies developed in the two designs are presented. 5 refs., 4 figs., 1 tab

  3. Resonance spectra of diabolo optical antenna arrays

    Directory of Open Access Journals (Sweden)

    Hong Guo

    2015-10-01

    Full Text Available A complete set of diabolo optical antenna arrays with different waist widths and periods was fabricated on a sapphire substrate by using a standard e-beam lithography and lift-off process. Fabricated diabolo optical antenna arrays were characterized by measuring the transmittance and reflectance with a microscope-coupled FTIR spectrometer. It was found experimentally that reducing the waist width significantly shifts the resonance to longer wavelength and narrowing the waist of the antennas is more effective than increasing the period of the array for tuning the resonance wavelength. Also it is found that the magnetic field enhancement near the antenna waist is correlated to the shift of the resonance wavelength.

  4. Miniaturised self-resonant split-ring resonator antenna

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Breinbjerg, Olav

    2009-01-01

    at the resonance is governed by the arc length of the monopole. Numerical and experimental results are presented for an antenna configuration of 1/23.4 wavelength in diameter (ka~0.134). The antenna is tuned to 50 ohms without any matching network, and its efficiency is measured to be 17.5%....

  5. Detection of gravitational waves with resonant antennas

    International Nuclear Information System (INIS)

    Ronga, Francesco

    2006-01-01

    The status of the 4 operating cylindrical gravitational waves resonant antenna detectors is summarized. A short review is given of the experimental results and of the next generation projects. Resonant detectors are now sensitive to the strongest potential sources of gravitational waves in our galaxy and in the local group. Recently interferometric detectors have achieved very good perfomances, but resonant detectors are still competitive particularly for what concern the very good live-time

  6. All-dielectric rod antenna array for terahertz communications

    Science.gov (United States)

    Withayachumnankul, Withawat; Yamada, Ryoumei; Fujita, Masayuki; Nagatsuma, Tadao

    2018-05-01

    The terahertz band holds a potential for point-to-point short-range wireless communications at sub-terabit speed. To realize this potential, supporting antennas must have a wide bandwidth to sustain high data rate and must have high gain and low dissipation to compensate for the free space path loss that scales quadratically with frequency. Here we propose an all-dielectric rod antenna array with high radiation efficiency, high gain, and wide bandwidth. The proposed array is integral to a low-loss photonic crystal waveguide platform, and intrinsic silicon is the only constituent material for both the antenna and the feed to maintain the simplicity, compactness, and efficiency. Effective medium theory plays a key role in the antenna performance and integrability. An experimental validation with continuous-wave terahertz electronic systems confirms the minimum gain of 20 dBi across 315-390 GHz. A demonstration shows that a pair of such identical rod array antennas can handle bit-error-free transmission at the speed up to 10 Gbit/s. Further development of this antenna will build critical components for future terahertz communication systems.

  7. Dielectric Covered Planar Antennas at Submillimeter Wavelengths for Terahertz Imaging

    Science.gov (United States)

    Chattopadhyay, Goutam; Gill, John J.; Skalare, Anders; Lee, Choonsup; Llombart, Nuria; Siegel, Peter H.

    2011-01-01

    Most optical systems require antennas with directive patterns. This means that the physical area of the antenna will be large in terms of the wavelength. When non-cooled systems are used, the losses of microstrip or coplanar waveguide lines impede the use of standard patch or slot antennas for a large number of elements in a phased array format. Traditionally, this problem has been solved by using silicon lenses. However, if an array of such highly directive antennas is to be used for imaging applications, the fabrication of many closely spaced lenses becomes a problem. Moreover, planar antennas are usually fed by microstrip or coplanar waveguides while the mixer or the detector elements (usually Schottky diodes) are coupled in a waveguide environment. The coupling between the antenna and the detector/ mixer can be a fabrication challenge in an imaging array at submillimeter wavelengths. Antennas excited by a waveguide (TE10) mode makes use of dielectric superlayers to increase the directivity. These antennas create a kind of Fabry- Perot cavity between the ground plane and the first layer of dielectric. In reality, the antenna operates as a leaky wave mode where a leaky wave pole propagates along the cavity while it radiates. Thanks to this pole, the directivity of a small antenna is considerably enhanced. The antenna consists of a waveguide feed, which can be coupled to a mixer or detector such as a Schottky diode via a standard probe design. The waveguide is loaded with a double-slot iris to perform an impedance match and to suppress undesired modes that can propagate on the cavity. On top of the slot there is an air cavity and on top, a small portion of a hemispherical lens. The fractional bandwidth of such antennas is around 10 percent, which is good enough for heterodyne imaging applications.The new geometry makes use of a silicon lens instead of dielectric quarter wavelength substrates. This design presents several advantages when used in the submillimeter

  8. 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

  9. A compact 5.5 GHz band-rejected UWB antenna using complementary split ring resonators.

    Science.gov (United States)

    Islam, M M; Faruque, M R I; Islam, M T

    2014-01-01

    A band-removal property employing microwave frequencies using complementary split ring resonators (CSRRs) is applied to design a compact UWB antenna wishing for the rejection of some frequency band, which is meanwhile exercised by the existing wireless applications. The reported antenna comprises optimization of a circular radiating patch, in which slotted complementary SRRs are implanted. It is printed on low dielectric FR4 substrate material fed by a partial ground plane and a microstrip line. Validated results exhibit that the reported antenna shows a wide bandwidth covering from 3.45 to more than 12 GHz, with a compact dimension of 22 × 26 mm(2), and VSWR WLAN band.

  10. Quality factor of an electrically small magnetic dipole antenna with magneto-dielectric core

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Breinbjerg, Olav

    2010-01-01

    In this work, we investigate the radiation Q of electrically small magnetic dipole antennas with magneto-dielectric core versus the antenna electrical size, permittivity and permeability of the core. The investigation is based on the exact theory for a spherical magnetic dipole antenna...

  11. A Dual Band Slotted Patch Antenna on Dielectric Material Substrate

    Directory of Open Access Journals (Sweden)

    M. Habib Ullah

    2014-01-01

    Full Text Available A low profile, compact dual band slotted patch antenna has been designed using finite element method-based high frequency full-wave electromagnetic simulator. The proposed antenna fabricated using LPKF printed circuit board (PCB fabrication machine on fiberglass reinforced epoxy polymer resin material substrate and the performance of the prototype has been measured in a standard far-field anechoic measurement chamber. The measured impedance bandwidths of (reflection coefficient <-10 dB 12.26% (14.3–16.2 GHZ, 8.24% (17.4–18.9 GHz, and 3.08% (19.2–19.8 have been achieved through the proposed antenna prototype. 5.9 dBi, 3.37 dBi, and 3.32 dBi peak gains have been measured and simulated radiation efficiencies of 80.3%, 81.9%, and 82.5% have been achieved at three resonant frequencies of 15.15 GHz, 18.2 GHz, and 19.5 GHz, respectively. Minimum gain variation, symmetric, and almost steady measured radiation pattern shows that the proposed antenna is suitable for Ku and K band satellite applications.

  12. High Gain and High Directive of Antenna Arrays Utilizing Dielectric Layer on Bismuth Titanate Ceramics

    Directory of Open Access Journals (Sweden)

    F. H. Wee

    2012-01-01

    Full Text Available A high gain and high directive microstrip patch array antenna formed from dielectric layer stacked on bismuth titanate (BiT ceramics have been investigated, fabricated, and measured. The antennas are designed and constructed with a combination of two-, four-, and six-BiT elements in an array form application on microwave substrate. For gain and directivity enhancement, a layer of dielectric was stacked on the BiT antenna array. We measured the gain and directivity of BiT array antennas with and without the dielectric layer and found that the gain of BiT array antenna with the dielectric layer was enhanced by about 1.4 dBi of directivity and 1.3 dB of gain over the one without the dielectric layer at 2.3 GHz. The impedance bandwidth of the BiT array antenna both with and without the dielectric layer is about 500 MHz and 350 MHz, respectively, which is suitable for the application of the WiMAX 2.3 GHz system. The utilization of BiT ceramics that covers about 90% of antenna led to high radiation efficiency, and small-size antennas were produced. In order to validate the proposed design, theoretical and measured results are provided and discussed.

  13. Plasmonic-Resonant Bowtie Antenna for Carbon Nanotube Photodetectors

    Directory of Open Access Journals (Sweden)

    Hongzhi Chen

    2012-01-01

    Full Text Available The design of bowtie antennas for carbon nanotube (CNT photodetectors has been investigated. CNT photodetectors have shown outstanding performance by using CNT as sensing element. However, detection wavelength is much larger than the diameter of the CNT, resulting in small fill factor. Bowtie antenna can confine light into a subwavelength volume based on plasmonic resonance, thus integrating a bowtie antenna to CNT photodetectors can highly improve photoresponse of the detectors. The electric field enhancement of bowtie antennas was calculated using the device geometry by considering fabrication difficulties and photodetector structure. It is shown that the electric field intensity enhancement increased exponentially with distance reduction between the CNT photodetector to the antenna. A redshift of the peak resonance wavelength is predicted due to the increase of tip angles of the bowtie antennas. Experimental results showed that photocurrent enhancement agreed well with theoretical calculations. Bowtie antennas may find wide applications in nanoscale photonic sensors.

  14. High efficiency on-chip Dielectric Resonator Antennna using micromachining technology

    KAUST Repository

    Sallam, Mai O.; Serry, Mohamed; Shamim, Atif; De Raedt, Walter; Sedky, Sherif; Vandenbosch, Guy A. E.; Soliman, Ezzeldin A.

    2015-01-01

    In this paper, a novel cylindrical Dielectric Resonator Antenna (DRA) operating at 60 GHz is introduced. The antenna is fabricated using a high-resistivity silicon wafer. The DR is defined in the wafer using micromachining technology. The feeding network is located at the other side of the wafer. The proposed antenna is simulated using HFSS and the results are verified by measurements. The antenna radiation is mainly along the broadside direction. The measured gain, radiation efficiency, and bandwidth are 7 dBi, 74.65%, and 2.23 GHz respectively. The antenna is characterized by high polarization purity where the maximum cross-polarization is -15 dB. © 2015 IEEE.

  15. High efficiency on-chip Dielectric Resonator Antennna using micromachining technology

    KAUST Repository

    Sallam, Mai O.

    2015-10-26

    In this paper, a novel cylindrical Dielectric Resonator Antenna (DRA) operating at 60 GHz is introduced. The antenna is fabricated using a high-resistivity silicon wafer. The DR is defined in the wafer using micromachining technology. The feeding network is located at the other side of the wafer. The proposed antenna is simulated using HFSS and the results are verified by measurements. The antenna radiation is mainly along the broadside direction. The measured gain, radiation efficiency, and bandwidth are 7 dBi, 74.65%, and 2.23 GHz respectively. The antenna is characterized by high polarization purity where the maximum cross-polarization is -15 dB. © 2015 IEEE.

  16. Resonant Elements for Tunable Reflectarray Antenna Design

    Directory of Open Access Journals (Sweden)

    M. Y. Ismail

    2012-01-01

    Full Text Available This paper presents an accurate analysis of different configurations of reflectarray resonant elements that can be used for the design of passive and tunable reflectarrays. Reflection loss and bandwidth performances of these reflectarray elements have been analyzed in the X-band frequency range with the Finite Integral Method technique, and the results have been verified by the waveguide scattering parameter measurements. The results demonstrate a reduction in the phase errors offering an increased static linear phase range of 225° which allows to improve the bandwidth performance of single layer reflectarray antenna. Moreover a maximum dynamic phase range of 320° and a volume reduction of 22.15% have been demonstrated for a 10 GHz reflectarray element based on the use of rectangular patch with an embedded circular slot.

  17. Characterization of Antennas on Dielectric and Magnetic Substrates Effective Medium Approximation

    Directory of Open Access Journals (Sweden)

    A. Sharaiha

    2009-12-01

    Full Text Available This paper presents a study of the effective medium approximation of a monopole antenna printed on either a dielectric or a magnetic substrate. Simple analytical formulas to determine the effective permeability of such an antenna have been proposed and validated. For this type of antenna as μr increases, the effective permeability will reach the value of 2 (maximum whereas, with the dielectric substrate, the effective permittivity continues to rise when increasing εr. This shows that, for very high permeability values, we will always have a size reduction below 30%.

  18. Miniaturized Planar Split-Ring Resonator Antenna

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Breinbjerg, Olav

    2009-01-01

    on how small this antenna can be. In practice, the lower bound is set by losses in utilized materials and manufacturing inaccuracies. As an example, an antenna of ka=0.09 was designed, fabricated and tested. Although the initially fabricated antenna prototype had the input impedance of 43 ohms......, it was subsequently tuned to 50 ohms simply by cutting out the excessive arm length. This tuning technique is especially useful in practical applications, since it allows the antenna to be tuned in-place and thereby compensate for various inaccuracies as well as for an antenna environment....

  19. Compact Dual-Band Zeroth-Order Resonance Antenna

    International Nuclear Information System (INIS)

    Xu He-Xiu; Wang Guang-Ming; Gong Jian-Qiang

    2012-01-01

    A novel microstrip zeroth-order resonator (ZOR) antenna and its equivalent circuit model are exploited with two zeroth-order resonances. It is constructed based on a resonant-type composite right/left handed transmission line (CRLH TL) using a Wunderlich-shaped extended complementary single split ring resonator pair (W-ECSSRRP) and a series capacitive gap. The gap either can be utilized for double negative (DNG) ZOR antenna or be removed to engineer a simplified elision-negative ZOR (ENG) antenna. For verification, a DNG ZOR antenna sample is fabricated and measured. Numerical and experimental results agree well with each other, indicating that the omnidirectional radiations occur at two frequency bands which are accounted for by two shunt branches in the circuit model. The size of the antenna is 49% more compact than its previous counterpart. The superiority of W-ECSSRRP over CSSRRP lies in the lower fundamental resonance of the antenna by 38.2% and the introduction of a higher zeroth-order resonance. (fundamental areas of phenomenology(including applications))

  20. Broadbanding of circularly polarized patch antenna by waveguided magneto-dielectric metamaterial

    Directory of Open Access Journals (Sweden)

    Xin Mi Yang

    2015-12-01

    Full Text Available Design of bandwidth-enhanced circularly polarized (CP patch antenna using artificial magneto-dielectric substrate was investigated. The artificial magneto-dielectric material adopted here takes the form of waveguided metamaterial (WG-MTM. In particular, the embedded meander line (EML structure was employed as the building element of the WG-MTM. As verified by the retrieved effective medium parameters, the EML-based waveguided magneto-dielectric metamaterial (WG-MDM exhibits two-dimensionally isotropic magneto-dielectric property with respect to TEM wave excitations applied in two orthogonal directions. A CP patch antenna loaded with the EML-based WG-MDM (WG-MDM antenna has been proposed and its design procedure is described in detail. Simulation results show that the impedance and axial ratio bandwidths of the WG-MDM antenna have increased by 125% and 133%, respectively, compared with those obtained with pure dielectric substrate offering the same patch size. The design of the novel WG-MDM antenna was also validated by measurement results, which show good agreement with their simulated counterparts.

  1. A Compact 5.5 GHz Band-Rejected UWB Antenna Using Complementary Split Ring Resonators

    Directory of Open Access Journals (Sweden)

    M. M. Islam

    2014-01-01

    Full Text Available A band-removal property employing microwave frequencies using complementary split ring resonators (CSRRs is applied to design a compact UWB antenna wishing for the rejection of some frequency band, which is meanwhile exercised by the existing wireless applications. The reported antenna comprises optimization of a circular radiating patch, in which slotted complementary SRRs are implanted. It is printed on low dielectric FR4 substrate material fed by a partial ground plane and a microstrip line. Validated results exhibit that the reported antenna shows a wide bandwidth covering from 3.45 to more than 12 GHz, with a compact dimension of 22 × 26 mm2, and VSWR < 2, observing band elimination of 5.5 GHz WLAN band.

  2. Normal modes and quality factors of spherical dielectric resonators: I ...

    Indian Academy of Sciences (India)

    Eigenmodes; spherical resonators; spherical dielectric resonators; quality factors. PACS No. 42.50. .... Alternatively, introducing the angular momentum operator L defined as, L = (1/j)( r × ∇) ...... referee of the article for some helpful comments.

  3. Polymer (PDMS-Fe3O4) magneto-dielectric substrate for a MIMO antenna array

    Science.gov (United States)

    Alqadami, Abdulrahman Shueai Mohsen; Jamlos, Mohd Faizal; Soh, Ping Jack; Kamarudin, Muhammad Ramlee

    2016-01-01

    This paper presents the design of a 2 × 4 multiple-input multiple-output (MIMO) antenna array fabricated on a nanocomposite magneto-dielectric polymer substrate. The 10-nm iron oxide (Fe3O4) nanoparticles and polydimethylsiloxane (PDMS) composite is used as substrate to enhance the performance of a MIMO antenna array. The measured results showed up to 40.8 % enhancement in terms of bandwidth, 9.95 dB gain, and 57 % of radiation efficiency. Furthermore, it is found that the proposed magneto-dielectric (PDMS-Fe3O4) composite substrate provides excellent MIMO parameters such as correlation coefficient, diversity gain, and mutual coupling. The prototype of the proposed antenna is transparent, flexible, lightweight, and resistant against dust and corrosion. Measured results indicate that the proposed antenna is suitable for WLAN and ultra-wideband biomedical applications within frequency range of 5.33-7.70 GHz.

  4. Spectroscopy and Biosensing with Optically Resonant Dielectric Nanostructures

    OpenAIRE

    Krasnok, Alex; Caldarola, Martin; Bonod, Nicolas; Alú, Andrea

    2017-01-01

    Resonant dielectric nanoparticles (RDNs) made of materials with large positive dielectric permittivity, such as Si, GaP, GaAs, have become a powerful platform for modern light science, enabling various fascinating applications in nanophotonics and quantum optics. In addition to light localization at the nanoscale, dielectric nanostructures provide electric and magnetic resonant responses throughout the visible and infrared spectrum, low dissipative losses and optical heating, low doping effec...

  5. Analysis of a shielded TE011 mode composite dielectric resonator ...

    Indian Academy of Sciences (India)

    Abstract. Analysis of a TE011 mode composite sapphire–rutile dielectric resonator has been car- ried out to study the temperature variation of resonance frequency, close to the Cs atomic clock hyperfine frequency of 9.192 GHz. The complementary behavior of dielectric permittivity with tem- perature of the composite has ...

  6. A UWB Band-Pass Antenna with Triple-Notched Band Using Common Direction Rectangular Complementary Split-Ring Resonators

    Directory of Open Access Journals (Sweden)

    Bo Yan

    2013-01-01

    Full Text Available A novel ultrawideband (UWB antenna which has a triple-band notch function is presented. The proposed antenna can block interfering signals from C-band satellite communication systems, IEEE802.11a, and HIPERLAN/2 WLAN systems for example. The antenna is excited by using novel common direction rectangular complementary split-ring resonators (CSRR fabricated on radiating patch of the dielectric substrate with coplanar waveguide (CPW feed strip line. The voltage standing wave ratio (VSWR of the proposed antenna is less than 2.0 in the frequency band from 2.8 to 12 GHz, while showing a very sharp band-rejection performance at 3.9 GHz, 5.2 GHz, and 5.9 GHz. The measurement results show that the proposed antenna provides good omnidirectional field pattern over its whole frequency band excluding the rejected band, which is suitable for UWB applications.

  7. Zeroth order resonator (ZOR) based RFID antenna design

    Science.gov (United States)

    Masud, Muhammad Mubeen

    Meander-line and multi-layer antennas have been used extensively to design compact UHF radio frequency identification (RFID) tags; however the overall size reduction of meander-line antennas is limited by the amount of parasitic inductance that can be introduced by each meander-line segment, and multi-layer antennas can be too costly. In this study, a new compact antenna topology for passive UHF RFID tags based on zeroth order resonant (ZOR) design techniques is presented. The antenna consists of lossy coplanar conductors and either inter-connected inter-digital capacitor (IDC) or shunt inductor unit-cells with a ZOR frequency near the operating frequency of the antenna. Setting the ZOR frequency near the operating frequency is a key component in the design process because the unit-cells chosen for the design are inductive at the operating frequency. This makes the unit-cells very useful for antenna miniaturization. These new designs in this work have several benefits: the coplanar layout can be printed on a single layer, matching inductive loops that reduce antenna efficiency are not required and ZOR analysis can be used for the design. Finally, for validation, prototype antennas are designed, fabricated and tested.

  8. Next Generation of Magneto-Dielectric Antennas and Optimum Flux Channels

    Science.gov (United States)

    Yousefi, Tara

    There is an ever-growing need for broadband conformal antennas to not only reduce the number of antennas utilized to cover a broad range of frequencies (VHF-UHF) but also to reduce visual and RF signatures associated with communication systems. In many applications antennas needs to be very close to low-impedance mediums or embedded inside low-impedance mediums. However, for conventional metal and dielectric antennas to operate efficiently in such environments either a very narrow bandwidth must be tolerated, or enough loss added to expand the bandwidth, or they must be placed one quarter of a wavelength above the conducting surface. The latter is not always possible since in the HF through low UHF bands, critical to Military and Security functions, this quarter-wavelength requirement would result in impractically large antennas. Despite an error based on a false assumption in the 1950’s, which had severely underestimated the efficiency of magneto-dielectric antennas, recently demonstrated magnetic-antennas have been shown to exhibit extraordinary efficiency in conformal applications. Whereas conventional metal-and-dielectric antennas carrying radiating electric currents suffer a significant disadvantage when placed conformal to the conducting surface of a platform, because they induce opposing image currents in the surface, magnetic-antennas carrying magnetic radiating currents have no such limitation. Their magnetic currents produce co-linear image currents in electrically conducting surfaces. However, the permeable antennas built to date have not yet attained the wide bandwidth expected because the magnetic-flux-channels carrying the wave have not been designed to guide the wave near the speed of light at all frequencies. Instead, they tend to lose the wave by a leaky fast-wave mechanism at low frequencies or they over-bind a slow-wave at high frequencies. In this dissertation, we have studied magnetic antennas in detail and presented the design approach and

  9. Dielectric studies of fluids with reentrant resonators

    International Nuclear Information System (INIS)

    Goodwin, A.R.H.; Moldover, M.R.

    1993-01-01

    The authors have used a reentrant radio-frequency (rf) cavity as a resonator operating near 375 MHz to measure changes in the dielectric constant of fluids within it. The utility of these measurements was demonstrated by determining the dipole moment of 1,1,1,2,3,3-hexafluoropropane, a candidate replacement refrigerant (denoted R236ea) and by detecting the phase boundaries in the mixture [(1-x)C 2 H 6 + xCO 2 ], for the mole fraction x = 0.492. The densities of the coexisting phases of the mixture were determined using the Clausius-Mossotti relation which has errors on the order of 0.5% in this application. To test the accuracy of the present techniques, the rf resonator was calibrated with helium and then used to redetermine the molar polarizability A e of argon. The results were in excellent agreement with published values. The design of the reentrant resonator makes it suitable for use with corrosive fluids at temperature up to 400 degrees C

  10. Magnetically coupled Fano resonance of dielectric pentamer oligomer

    International Nuclear Information System (INIS)

    Zhang, Fuli; Li, Chang; He, Xuan; Chen, Lei; Fan, Yuancheng; Zhao, Qian; Zhang, Weihong; Zhou, Ji

    2017-01-01

    We present magnetically induced Fano resonance inside a dielectric metamaterial pentamer composed of ceramic bricks. Unlike previous reports where different sizes of dielectric resonators were essential to produce Fano resonance, under external magnetic field excitation, central and outer dielectric bricks with identical sizes exhibit in-phase and out-of-phase magnetic Mie oscillations. An asymmetric line shape of Fano resonance along with enhanced group delay is observed due to the interference between the magnetic resonance of the central brick and the symmetric magnetic resonance of outer bricks. Besides, Fano resonance blueshifts with the increasing resonance of the smaller central brick. The thermal-dependent permittivity of ceramics allows Fano resonance to be reversibly tuned by 300 MHz when temperature varies by 60 °C. (paper)

  11. Photocurrent mapping of near-field optical antenna resonances

    KAUST Repository

    Barnard, Edward S.; Pala, Ragip A.; Brongersma, Mark L.

    2011-01-01

    An increasing number of photonics applications make use of nanoscale optical antennas that exhibit a strong, resonant interaction with photons of a specific frequency. The resonant properties of such antennas are conventionally characterized by far-field light-scattering techniques. However, many applications require quantitative knowledge of the near-field behaviour, and existing local field measurement techniques provide only relative, rather than absolute, data. Here, we demonstrate a photodetector platform that uses a silicon-on-insulator substrate to spectrally and spatially map the absolute values of enhanced fields near any type of optical antenna by transducing local electric fields into photocurrent. We are able to quantify the resonant optical and materials properties of nanoscale (∼50nm) and wavelength-scale (∼1μm) metallic antennas as well as high-refractive-index semiconductor antennas. The data agree well with light-scattering measurements, full-field simulations and intuitive resonator models. © 2011 Macmillan Publishers Limited. All rights reserved.

  12. Photocurrent mapping of near-field optical antenna resonances

    KAUST Repository

    Barnard, Edward S.

    2011-08-21

    An increasing number of photonics applications make use of nanoscale optical antennas that exhibit a strong, resonant interaction with photons of a specific frequency. The resonant properties of such antennas are conventionally characterized by far-field light-scattering techniques. However, many applications require quantitative knowledge of the near-field behaviour, and existing local field measurement techniques provide only relative, rather than absolute, data. Here, we demonstrate a photodetector platform that uses a silicon-on-insulator substrate to spectrally and spatially map the absolute values of enhanced fields near any type of optical antenna by transducing local electric fields into photocurrent. We are able to quantify the resonant optical and materials properties of nanoscale (∼50nm) and wavelength-scale (∼1μm) metallic antennas as well as high-refractive-index semiconductor antennas. The data agree well with light-scattering measurements, full-field simulations and intuitive resonator models. © 2011 Macmillan Publishers Limited. All rights reserved.

  13. Pulsed electromagnetic field radiation from a narrow slot antenna with a dielectric layer

    NARCIS (Netherlands)

    Štumpf, M.; De Hoop, A.T.; Lager, I.E.

    2010-01-01

    Analytic time domain expressions are derived for the pulsed electromagnetic field radiated by a narrow slot antenna with a dielectric layer in a two?dimensional model configuration. In any finite time window of observation, exact pulse shapes for the propagated, reflected, and refracted wave

  14. Sensitivity limits of capacitive transducer for gravitational wave resonant antennas

    Energy Technology Data Exchange (ETDEWEB)

    Bassan, M; Pizzella, G [Rome Tor Vergata Univ. (Italy). Dip. di Fisica

    1996-12-01

    It is analyzed the performance of a resonant gravitational wave antenna equipped with a resonant, d.c. biased capacitive transducer, an untuned superconducting matching circuit and a d.c. Squid. It is derived simple relations for the detector energy sensitivity that serve as guidelines for device development and it is shown that, with reasonable improvements in Squid technology, an effective temperature for burst detection of 2miK can be achieved.

  15. Subwavelength resonant antennas enhancing electromagnetic energy harvesting

    Science.gov (United States)

    Oumbe Tekam, Gabin; Ginis, Vincent; Seetharamdoo, Divitha; Danckaert, Jan

    2016-04-01

    In this work, an electromagnetic energy harvester operating at microwave frequencies is designed based on a cut- wire metasurface. This metamaterial is known to contain a quasistatic electric dipole resonator leading to a strong resonant electric response when illuminated by electromagnetic fields.1 Starting from an equivalent electrical circuit, we analytically design the parameters of the system to tune the resonance frequency of the harvester at the desired frequency band. Subsequently, we compare these results with numerical simulations, which have been obtained using finite elements numerical simulations. Finally, we optimize the design by investigating the best arrangement for energy harvesting by coupling in parallel and in series many single layers of cut-wire metasurfaces. We also discuss the implementation of different geometries and sizes of the cut-wire metasurface for achieving different center frequencies and bandwidths.

  16. Passive UHF RFID Tags with Specific Printed Antennas for Dielectric and Metallic Objects Applications

    Directory of Open Access Journals (Sweden)

    K. Siakavara

    2017-09-01

    Full Text Available Design process and respective results for the synthesis of specific Radiofrequency Identification(RFID tag antennas, suitable for dielectric and metallic objects, are presented. The antennas were designed for the UHF(865MHz-869MHz band and their basic configuration is that of the printed spiral type. Six modification steps to the classical spiral layout are proposed and it was proved that they can lead to tags with high readability and reading distances up to 10m when designed for dielectric object and up to 7m in the case of metallic objects. The results of the measurements of the fabricated tags are explained via theoretical evaluations which take into account reflection phenomena, that are present in a real environment at which the tags are used.

  17. Computation of the radiation Q of dielectric-loaded electrically small antennas in integral equation formulations

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.

    2016-01-01

    A new technique for estimating the impedance frequency bandwidth of electrically small antennas loaded with magneto-dielectric material from a single-frequency simulation in a surface integral equation solver is presented. The estimate is based on the inverse of the radiation Q computed using newly...... derived expressions for the stored energy and the radiated power of arbitrary coupled electric and magnetic currents in free space....

  18. Resonances and dipole moments in dielectric, magnetic, and magnetodielectric cylinders

    DEFF Research Database (Denmark)

    Dirksen, A.; Arslanagic, Samel; Breinbjerg, Olav

    2011-01-01

    An eigenfunction solution to the problem of plane wave scattering by dielectric, magnetic, and magnetodielectric cylinders is used for a systematic investigation of their resonances. An overview of the resonances with electric and magnetic dipole moments, needed in, e.g., the synthesis...

  19. Dual-Resonant Implantable Circular Patch Antenna for Biotelemetry Communication

    Directory of Open Access Journals (Sweden)

    Rongqiang Li

    2016-01-01

    Full Text Available A compact broadband implantable circular patch antenna is designed and experimentally demonstrated for Medical Implant Communications Service (MICS band (402–405 MHz. Compared with other similar implantable antennas, the proposed antenna incorporates three advantages for biotelemetry communication. First, it can realize a broad impedance bandwidth by exhibiting dual resonances. Second, it can obtain a compact structure by introducing two arc-shaped slots, a rectangular slot and a circular slot on metal radiating patch. Finally, it can display a friendly shape by using a circular structure. The proposed antenna occupies a volume of about 431.5 mm3 (10.42 × 1.27π mm3, which is a compromise between miniaturization and bandwidth. The measured −10 dB impedance bandwidth is 55 MHz (385–440 MHz. Furthermore, the radiation performance and human body safety consideration of the antenna are examined and characterized.

  20. 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.

  1. A Resonant Scanning Dipole-Antenna Probe for Enhanced Nanoscale Imaging

    NARCIS (Netherlands)

    Neumann, L.; van 't Oever, Jan Joannes Frederik; van Hulst, N.F.

    2013-01-01

    We present a scanning antenna probe that provides 35 nm optical hotspots with a 16-fold excitation enhancement. A resonant optical antenna, tuned to operation in the visible, is carved into the aluminum-coated scanning probe. The antenna resonances, field localization, excitation, and polarization

  2. Optimal design of resonant-mass gravitational wave antennas

    International Nuclear Information System (INIS)

    Price, J.C.

    1987-01-01

    A new generation of resonant-mass gravitational wave antennas, to be operated at ultralow temperatures, is under development by several research groups. This paper presents a theory for the optimal design of the new antennas. First, a general sensitivity limit is derived, which may be applied to any linear instrument for which the design figure of merit is the signal-to-noise ratio (SNR). By replacing the amplifier by its noise resistance and considering the energy dissipated in the noise resistance when a signal is applied, it is possible to show that the optimally filtered SNR is less than or equal to E/sub r//(kT/sub n/), the energy dissipated in the noise resistance divided by Boltzmann's constant times the amplifier noise temperature. This sensitivity limit will be achieved if the instrument is lossless, in which case the energy dissipated in the noise resistance is equal to the energy deposited in the system by the signal. For resonant-mass gravitational wave antennas, if the amplifier is identified as the mechanical amplifier (transducer and electronic amplifier together), then the lossless limit is accessible in practice. A useful point of view is that optimal antenna designs are those that are most loss tolerant: those that achieve the limiting SNR with the lowest possible mechanical Q values. The techniques of network synthesis may be used to design mechanical networks for matching the main antenna mass to the mechanical amplifier that are optimal in this sense. A class of loss-tolerant networks has been synthesized; their properties are summarized in a set of design charts that give the Q requirements and bandwidth as a function of the number of modes, the temperature, and the amplifier noise resistance and noise temperature

  3. Longitudinally mounted light emitting plasma in a dielectric resonator

    Energy Technology Data Exchange (ETDEWEB)

    Gilliard, Richard; DeVincentis, Marc; Hafidi, Abdeslam; O' Hare, Daniel; Hollingsworth, Gregg [LUXIM Corporation, 1171 Borregas Avenue, Sunnyvale, CA 94089 (United States)

    2011-06-08

    Methods for coupling power from a dielectric resonator to a light-emitting plasma have been previously described (Gilliard et al IEEE Trans. Plasma Sci. at press). Inevitably, regardless of the efficiency of power transfer, much of the emitted light is absorbed in the resonator itself which physically surrounds much if not all of the radiating material. An investigation into a method is presented here for efficiently coupling power to a longitudinally mounted plasma vessel which is mounted on the surface of the dielectric material of the resonator, thereby eliminating significant absorption of light within the resonator structure. The topology of the resonator and its physical properties as well as those of the metal halide plasma are presented. Results of basic models of the field configuration and plasma are shown as well as a configuration suitable as a practical light source.

  4. DIELECTRIC WAKE FIELD RESONATOR ACCELERATOR MODULE

    Energy Technology Data Exchange (ETDEWEB)

    Hirshfield, Jay L.

    2013-11-06

    Results are presented from experiments, and numerical analysis of wake fields set up by electron bunches passing through a cylindrical or rectangular dielectric-lined structure. These bunches excite many TM-modes, with Ez components of the wake fields sharply localized on the axis of the structure periodically behind the bunches. The experiment with the cylindrical structure, carried out at ATF Brookhaven National Laboratory, used up to three 50 MeV bunches spaced by one wake field period (21 cm) to study the superposition of wake fields by measuring the energy loss of each bunch after it passed through the 53-cm long dielectric element. The millimeter-wave spectrum of radiation excited by the passage of bunches is also studied. Numerical analysis was aimed not only to simulate the behavior of our device, but in general to predict dielectric wake field accelerator performance. It is shown that one needs to match the radius of the cylindrical dielectric channel with the bunch longitudinal rms-length to achieve optimal performance.

  5. Manipulation of surface plasmon resonance of a graphene-based Au aperture antenna in visible and near-infrared regions

    Science.gov (United States)

    Wan, Yuan; An, Yashuai; Tao, Zhi; Deng, Luogen

    2018-03-01

    Behaviors of surface plasmon resonance (SPR) of a graphene-based Au aperture antenna are investigated in visible and near-infrared (vis-NIR) regions. Compared with the SPR wavelength of a traditional Au aperture antenna, the SPR wavelength of the graphene-based Au aperture antenna shows a remarkable blue shift due to the redistribution of the electric field in the proposed structure. The electric field of the graphene-based Au aperture antenna is highly localized on the surface of the graphene in the aperture and redistributed to be a standing wave. Moreover, the SPR of a graphene-based Au aperture antenna is sensitive to the thickness and the refractive index of the dielectric layer, the graphene Fermi energy, the refractive index of the environment and the polarization direction of the incident light. Finally, we find the wavelength, intensity and phase of the reflected light of the graphene-based Au aperture antenna array can be actively modulated by varying the graphene Fermi energy. The proposed structure provides a promising platform for realizing a tunable optical filter, a highly sensitive refractive index sensor, and other actively tunable optical and optoelectronic devices.

  6. Dielectrically-Loaded Cylindrical Resonator-Based Wireless Passive High-Temperature Sensor

    Directory of Open Access Journals (Sweden)

    Jijun Xiong

    2016-12-01

    Full Text Available The temperature sensor presented in this paper is based on a microwave dielectric resonator, which uses alumina ceramic as a substrate to survive in harsh environments. The resonant frequency of the resonator is determined by the relative permittivity of the alumina ceramic, which monotonically changes with temperature. A rectangular aperture etched on the surface of the resonator works as both an incentive and a coupling device. A broadband slot antenna fed by a coplanar waveguide is utilized as an interrogation antenna to wirelessly detect the sensor signal using a radio-frequency backscattering technique. Theoretical analysis, software simulation, and experiments verified the feasibility of this temperature-sensing system. The sensor was tested in a metal-enclosed environment, which severely interferes with the extraction of the sensor signal. Therefore, frequency-domain compensation was introduced to filter the background noise and improve the signal-to-noise ratio of the sensor signal. The extracted peak frequency was found to monotonically shift from 2.441 to 2.291 GHz when the temperature was varied from 27 to 800 °C, leading to an average absolute sensitivity of 0.19 MHz/°C.

  7. Robust design of microlenses arrays employing dielectric resonators metasurfaces

    NARCIS (Netherlands)

    Silvestri, F.; Gerini, G.; Bäumer, S.M.B.

    2017-01-01

    In the last years, much interest has grown around the concept of optical surfaces employing high contrast dielectric resonators. However, a systematic approach for the design of this optical surfaces under particular requirements has never been proposed. In this contribution, we describe this

  8. Compact, Wearable Antennas for Battery-Less Systems Exploiting Fabrics and Magneto-Dielectric Materials

    Directory of Open Access Journals (Sweden)

    Alessandra Costanzo

    2014-08-01

    Full Text Available In this paper, we describe some promising solutions to the modern need for wearable, energy-aware, miniaturized, wireless systems, whose typical envisaged application is a body area network (BAN. To reach this goal, novel materials are adopted, such as fabrics, in place of standard substrates and metallizations, which require a systematic procedure for their electromagnetic characterization. Indeed, the design of such sub-systems represents a big issue, since approximate approaches could result in strong deviations from the actual system performance. To face this problem, we demonstrate our design procedure, which is based on the concurrent use of electromagnetic software tools and nonlinear circuit-level techniques, able to simultaneously predict the actual system behavior of an antenna system, consisting of the radiating and of the nonlinear blocks, at the component level. This approach is demonstrated for the design of a fully-wearable tri-band rectifying antenna (rectenna and of a button-shaped, electrically-small antenna deploying a novel magneto-dielectric substrate. Simulations are supported by measurements, both in terms of antenna port parameters and far-field results.

  9. Wireless energy transfer: Dielectric lens antennas for beam shaping in wireless power-transfer applications

    Science.gov (United States)

    Gonçalves, Ricardo; Carvalho, Nuno B.; Pinho, Pedro

    2017-02-01

    In the current contest of wireless systems, the last frontier remains the cut of the power cord. In that sense, the interest over wireless energy transfer technologies in the past years has grown exponentially. However, there are still many challenges to be overcome in order to enable wireless energy transfer full potential. One of the focus in the development of such systems is the design of very-high-gain, highly efficient, antennas that can compensate for the propagation loss of radio signals over the air. In this paper, we explore the design and manufacturing process of dielectric lenses, fabricated using a professional-grade desktop 3D printer. Lens antennas are used in order to increase beam efficiency and therefore maximize the efficiency of a wireless power-transfer system operating at microwave frequencies in the Ku band. Measurements of two fabricated prototypes showcase a large directivity, as predicted with simulations. xml:lang="fr"

  10. Design of a dielectric resonator receive array at 7 Tesla using detunable ceramic resonators

    Science.gov (United States)

    Ruytenberg, Thomas; Webb, Andrew G.

    2017-11-01

    Ceramic-based dielectric resonators can be used for high frequency magnetic resonance imaging and microscopy. When used as elements in a transmit array, the intrinsically low inter-element coupling allows flexibility in designing different geometric arrangements for different regions-of-interest. However, without being able to detune such resonators, they cannot be used as elements in a receive-only array. Here, we propose and implement a method, based on mode-disruption, for detuning ceramic-based dielectric resonators to enable them to be used as receive-only elements.

  11. Self-Resonant Electrically Small Loop Antennas for Hearing-Aids Application

    DEFF Research Database (Denmark)

    Zhang, Jiaying; Breinbjerg, Olav

    2010-01-01

    Two novel self-resonant electrically small antennas are proposed in this paper, which are designed for hearing aids applications. They are miniaturized by using the capacitive and inductive coupling mechanism between two loops, and the antenna impedance can be matched to a specific value without...... using any additional matching network and lumped components. The dimension of the proposed antenna is 0.10λ0×0.03λ0, and it is designed to be resonant at 900 MHz. Both the analytical model and numerical simulations are discussed and explained. The antenna is also fabricated and measured in an anechoic...... chamber. The measurement methods for electrically small antennas are reported....

  12. Manipulation of plasmonic resonances in graphene coated dielectric cylinders

    KAUST Repository

    Ge, Lixin

    2016-11-16

    Graphene sheets can support surface plasmon as the Dirac electrons oscillate collectively with electromagnetic waves. Compared with the surface plasmon in conventional metal (e.g., Ag and Au), graphene plasmonic owns many remarkable merits especially in Terahertz and far infrared frequencies, such as deep sub-wavelength, low loss, and high tunability. For graphene coated dielectric nano-scatters, localized surface plasmon (LSP)exist and can be excited under specific conditions. The LSPs are associated with the Mie resonance modes, leading to extraordinary large scattering and absorption cross section. In this work, we study systematically the optical scattering properties for graphene coated dielectric cylinders. It is found that the LSP can be manipulated by geometrical parameters and external electric gating. Generally, the resonance frequencies for different resonance modes are not the same. However, under proper design, we show that different resonance modes (e.g., dipole mode, quadruple mode etc.) can be excited at the same frequency. Thus, the scattering and absorption by graphene coated dielectric cylinders can indeed overcome the single channel limit. Our finding may open up new avenues in applications for the graphene-based THz optoelectronic devices.

  13. Analysis and design of terahertz antennas based on plasmonic resonant graphene sheets

    International Nuclear Information System (INIS)

    Tamagnone, M.; Gómez-Díaz, J. S.; Perruisseau-Carrier, J.; Mosig, J. R.

    2012-01-01

    Resonant graphene antennas used as true interfaces between terahertz (THz) space waves and a source/detector are presented. It is shown that in addition to the high miniaturization related to the plasmonic nature of the resonance, graphene-based THz antenna favorably compare with typical metal implementations in terms of return loss and radiation efficiency. Graphene antennas will contribute to the development of miniature, efficient, and potentially transparent all-graphene THz transceivers for emerging communication and sensing application.

  14. Equilateral Triangular Dielectric Resonator Nantenna at Optical Frequencies for Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Waleed Tariq Sethi

    2015-01-01

    Full Text Available The last decade has witnessed a remarkable growth in the telecommunication industry. With the introduction of smart gadgets, the demand for high data rate and bandwidth for wireless applications have increased exponentially at the cost of exponential consumption of energy. The latter is pushing the research and industry communities to devise green communication solutions that require the design of energy saving devices and techniques in one part and ambient energy harvesting techniques in the other part. With the advent of nanocomponents fabrication technology, researchers are now able to tap into the THz frequency regime and fabricate optical low profile antennas at a nanoscale. Optical antennas have proved their potential and are revolutionizing a class of novel optical detectors, interconnectors, sensors, and energy harvesting related fields. Authors in this paper propose an equilateral triangular dielectric resonator nantenna (ETDRNA working at 193.5 THz standard optical frequency. The simulated antenna achieves an impedance bandwidth from 192.3 THz to 197.3 THz with an end-fire directivity of 8.6 dBi, covering the entire standard optical window of C-band. Numerical demonstrations prove the efficiency of the nantenna at the frequencies of interest, making it a viable candidate for future green energy harvesting and high speed optical applications.

  15. Complex permittivity measurements of ferroelectric employing composite dielectric resonator technique

    Czech Academy of Sciences Publication Activity Database

    Krupka, J.; Zychowicz, T.; Bovtun, Viktor; Veljko, Sergiy

    2006-01-01

    Roč. 53, č. 10 (2006), s. 1883-1888 ISSN 0885-3010 R&D Projects: GA AV ČR(CZ) IAA1010213; GA ČR(CZ) GA202/04/0993; GA ČR(CZ) GA202/06/0403 Institutional research plan: CEZ:AV0Z10100520 Keywords : dielectric resonator * ferroelectrics * microwave measurements Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.729, year: 2006

  16. Multipolar modes in dielectric disk resonator for wireless power transfer

    Science.gov (United States)

    Song, Mingzhao; Belov, Pavel; Kapitanova, Polina

    2017-09-01

    We demonstrate a magnetic resonant WPT system based on dielectric disk resonators and investigated the WPT efficiency as a function of separation. It has been demonstrated that the power transfer can be achieved at different multipolar modes. The numerical study shows that the highest WPT efficiency of 99% can be obtained for the MQ mode in an ideal case. However, the efficiency of MQ mode decays much faster than the MD mode which suggests that a trade-off has to be made in the practical WPT system design.

  17. Finite-size resonance dielectric cylinder in a rectangular waveguide

    International Nuclear Information System (INIS)

    Chuprina, V.N.; Khizhnyak, N.A.

    1988-01-01

    The problem on resonance spread of an electromagnetic wave by a dielectric circular cylinder of finite size in a rectangular waveguide is solved by a numerical-analytical method. The cylinder axes are parallel. The cylinder can be used as a resonance tuning element in accelerating SHF-sections. Problems on cutting off linear algebraic equation systems, to which relations of macroscopic electrodynamics in the integral differential form written for the concrete problem considered here are reduced by analytical transformations, are investigated in the stage of numerical analysis. Theoretical dependences of the insertion of the voltage standing wave coefficient on the generator wave length calculated for different values of problem parameters are constracted

  18. Enhanced optical-to-THz conversion efficiency of photoconductive antenna using dielectric nano-layer encapsulation

    Science.gov (United States)

    Gupta, Abhishek; Rana, Goutam; Bhattacharya, Arkabrata; Singh, Abhishek; Jain, Ravikumar; Bapat, Rudheer D.; Duttagupta, S. P.; Prabhu, S. S.

    2018-05-01

    Photoconductive antennas (PCAs) are among the most conventional devices used for emission as well as detection of terahertz (THz) radiation. However, due to their low optical-to-THz conversion efficiencies, applications of these devices in out-of-laboratory conditions are limited. In this paper, we report several factors of enhancement in THz emission efficiency from conventional PCAs by coating a nano-layer of dielectric (TiO2) on the active area between the electrodes of a semi-insulating GaAs-based device. Extensive experiments were done to show the effect of thicknesses of the TiO2 layer on the THz power enhancement with different applied optical power and bias voltages. Multiphysics simulations were performed to elucidate the underlying physics behind the enhancement of efficiency of the PCA. Additionally, this layer increases the robustness of the electrode gaps of the PCAs with high electrical insulation as well as protect it from external dust particles.

  19. Design of a broadband hexagonal-shaped zeroth-order resonance antenna with metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Dong Sik; Kim, Kang Wook; Choi, Hyun Chul [Kyungpook National University, Daegu (Korea, Republic of)

    2014-11-15

    A broadband hexagonal-shaped metamaterials (MTMs)-based zeroth-order resonant (ZOR) antenna was designed and fabricated. The hexagonal shape of a top patch on a mushroom structure makes not only direct-current paths between the two ends of the patch but also round-current paths along the outside of the patch, thereby widening the resonance frequency of the mushroom MTM antenna. According to the shape of the hexagon patch, the presented antenna achieved impedance bandwidth of 58.6% corresponding to ultra-wideband technology. The proposed ZOR antenna was modeled by utilizing a composite right- and left-handed (CRLH) transmission line and provided 4 to 9.3 dBi of the antenna gain with reduced size as compared to conventional microstrip antennas at Ku- to K-band frequencies.

  20. Electromagnetically induced transparency with wide band in all-dielectric microstructure based on Mie resonances

    International Nuclear Information System (INIS)

    Zhu, Lei; Dong, Liang

    2014-01-01

    We numerically demonstrate that a broadband electromagnetically induced transparency–like (EIT-like) effect can be achieved in an all-dielectric microstructure consisting of a dielectric bar and six dielectric bricks. With proper excitations, the dielectric bar and bricks serve as bright and dark elements via the Mie electric and magnetic resonances, respectively. In particular, the mutual couplings between the Mie electric and magnetic resonances induce a broad transparency window. The nature of resonances of the broadband EIT-like effect in an all-dielectric microstructure is investigated by numerical simulation and a coupled oscillator model. Results reveal that significant enhancement of coupling interactions between dielectric resonators leads to a broadband EIT-like effect. Such a dielectric EIT-like structure is promising for future applications in nonlinear optics, slow light devices, and filters. (paper)

  1. Influence of nanocrystalline diamond on resonant properties of gold plasmonic antennas

    Czech Academy of Sciences Publication Activity Database

    Kvapil, M.; Kromka, Alexander; Rezek, Bohuslav; Kalousek, R.; Křápek, V.; Dub, P.; Šikola, T.

    2016-01-01

    Roč. 213, č. 6 (2016), 1564-1571 ISSN 1862-6300 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:68378271 Keywords : antenna resonance wavelength * electric field enhancement * FDTD * nanocrystalline diamond * plasmonic antenna Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.775, year: 2016

  2. Resonant wave energy harvester based on dielectric elastomer generator

    Science.gov (United States)

    Moretti, Giacomo; Pietro Rosati Papini, Gastone; Righi, Michele; Forehand, David; Ingram, David; Vertechy, Rocco; Fontana, Marco

    2018-03-01

    Dielectric elastomer generators (DEGs) are a class of capacitive solid-state devices that employ highly stretchable dielectrics and conductors to convert mechanical energy into high-voltage direct-current electricity. Their promising performance in terms of convertible energy and power density has been mostly proven in quasi-static experimental tests with prescribed deformation. However, the assessment of their ability in harvesting energy from a dynamic oscillating source of mechanical energy is crucial to demonstrate their effectiveness in practical applications. This paper reports a first demonstration of a DEG system that is able to convert the oscillating energy carried by water waves into electricity. A DEG prototype is built using a commercial polyacrylate film (VHB 4905 by 3M) and an experimental campaign is conducted in a wave-flume facility, i.e. an artificial basin that makes it possible to generate programmed small-scale waves at different frequencies and amplitudes. In resonant conditions, the designed system demonstrates the delivery of a maximum of 0.87 W of electrical power output and 0.64 J energy generated per cycle, with corresponding densities per unit mass of dielectric elastomer of 197 W kg-1 and 145 J kg-1. Additionally, a notable maximum fraction of 18% of the input wave energy is converted into electricity. The presented results provide a promising demonstration of the operation and effectiveness of ocean wave energy converters based on elastic capacitive generators.

  3. Ion cyclotron resonant heating 2 x 1700 loop antenna for the Tandem Mirror Experiment-Upgrade

    International Nuclear Information System (INIS)

    Brooksby, C.A.; Ferguson, S.W.; Molvik, A.W.; Barter, J.

    1985-01-01

    This paper reviews the mechanical design and improvements that have taken place on the loop type ion cyclotron resonance heating (ICRH) antennas that are located in the center cell region of the Tandem Mirror Experiment-Upgrade (TMX-U)

  4. Resonant Frequency Calculation and Optimal Design of Peano Fractal Antenna for Partial Discharge Detection

    Directory of Open Access Journals (Sweden)

    Jian Li

    2012-01-01

    Full Text Available Ultra-high-frequency (UHF approaches have caught increasing attention recently and have been considered as a promising technology for online monitoring partial discharge (PD signals. This paper presents a Peano fractal antenna for UHF PD online monitoring of transformer with small size and multiband. The approximate formula for calculating the first resonant frequency of the Peano fractal antenna is presented. The results show that the first resonant frequency of the Peano fractal antenna is smaller than the Hilbert fractal antenna when the outer dimensions are equivalent approximately. The optimal geometric parameters of the antenna were obtained through simulation. Actual PD experiments had been carried out for two typically artificial insulation defect models, while the proposed antenna and the existing Hilbert antenna were both used for the PD measurement. The experimental results show that Peano fractal antenna is qualified for PD online UHF monitoring and a little more suitable than the Hilbert fractal antenna for pattern recognition by analyzing the waveforms of detected UHF PD signals.

  5. Shear Alfven wave excitation by direct antenna coupling and fast wave resonant mode conversion

    International Nuclear Information System (INIS)

    Borg, G.G.

    1994-01-01

    Antenna coupling to the shear Alfven wave by both direct excitation and fast wave resonant mode conversion is modelled analytically for a plasma with a one dimensional linear density gradient. We demonstrate the existence of a shear Alfven mode excited directly by the antenna. For localised antennas, this mode propagates as a guided beam along the steady magnetic field lines intersecting the antenna. Shear Alfven wave excitation by resonant mode conversion of a fast wave near the Alfven resonance layer is also demonstrated and we prove that energy is conserved in this process. We compare the efficiency of these two mechanisms of shear Alfven wave excitation and present a simple analytical formula giving the ratio of the coupled powers. Finally, we discuss the interpretation of some experimental results. 45 refs., 7 figs

  6. 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

  7. 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).

  8. Radio antennas

    Science.gov (United States)

    Gibson, S. W.

    This book is concerned with providing an explanation of the function of an antenna without delving too deeply into the mathematics or theory. The characteristics of an antenna are examined, taking into account aspects of antenna radiation, wave motion on the antenna, resistance in the antenna, impedance, the resonant antenna, the effect of the ground, polarization, radiation patterns, coupling effects between antenna elements, and receiving vs. transmitting. Aspects of propagation are considered along with the types of antennas, transmission lines, matching devices, questions of antenna design, antennas for the lower frequency bands, antennas for more than one band, limited space antennas, VHF antennas, and antennas for 20, 15, and 10 meters. Attention is given to devices for measuring antenna parameters, approaches for evaluating the antenna, questions of safety, and legal aspects.

  9. Broadband Light Collection Efficiency Enhancement of Carbon Nanotube Excitons Coupled to Metallo-Dielectric Antenna Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Shayan, Kamran [Department; Rabut, Claire [Department; Kong, Xiaoqing [Department; Li, Xiangzhi [Department; Luo, Yue [Department; Mistry, Kevin S. [National Renewable; Blackburn, Jeffrey L. [National Renewable; Lee, Stephanie S. [Department; Strauf, Stefan [Department

    2017-11-09

    The realization of on-chip quantum networks ideally requires lossless interfaces between photons and solid-state quantum emitters. We propose and demonstrate on-chip arrays of metallo-dielectric antennas (MDA) that are tailored toward efficient and broadband light collection from individual embedded carbon nanotube quantum emitters by trapping air gaps on chip that form cavity modes. Scalable implementation is realized by employing polymer layer dry-transfer techniques that avoid solvent incompatibility issues, as well as a planar design that avoids solid-immersion lenses. Cryogenic measurements demonstrate 7-fold enhanced exciton intensity when compared to emitters located on bare wafers, corresponding to a light collection efficiency (LCE) up to 92% in the best case (average LCE of 69%) into a narrow output cone of +/-15 degrees that enables a priori fiber-to-chip butt coupling. The demonstrated MDA arrays are directly compatible with other quantum systems, particularly 2D materials, toward enabling efficient on-chip quantum light sources or spin-photon interfaces requiring unity light collection, both at cryogenic or room temperature.

  10. Dielectric resonance in ErFeO3 in the region of spin reorientation

    International Nuclear Information System (INIS)

    Dan'shin, N.K.; Kovtun, N.M.; Sdvizhkov, M.A.

    1984-01-01

    In the region of spin reorientation in ErFeO 3 in the millimetre wave range a dielectric resonance has been found - excitation of electromaqnetic field natural oscillations in spherical samples. The fregurncies of dielectric resonance in samples from ErFeO 3 possess strong independence of temperature and magnetic field in the vicinity of the spin reorientation for account of a strong growth in the magnetic susceptibility. The frequencies change most considerably in the region of low-temperature spin reorientation related to antiferromagnetic rare earth ordering. Strong anisotropy of magnetic susceptibility cases various temperature and field dependences of the dielectric resonance frequencies at different orientations of the exciting electromagnetic field relative to the crystal axes. It is shown that the method of dielectric resonance permits to determine with high accuracy the temperatures of spontaneous - and crystal fields of induced phase transformations. The crystal dielectric permittivity and magnetic permeability dispersion are determined

  11. 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.

  12. Ultrasmall Dual-Band Metamaterial Antennas Based on Asymmetrical Hybrid Resonators

    Directory of Open Access Journals (Sweden)

    Ji-Xu Zhu

    2016-01-01

    Full Text Available A new type of hybrid resonant circuit model is investigated theoretically and experimentally. The resonant model consists of a right hand (RH patch part and a composite right and left handed (CRLH part (RH + CRLH, which determines a compact size and also a convenient frequency modulation characteristic for the proposed antennas. For experimental demonstration, two antennas are fabricated. The former dual-band antenna operating at f-1=3.5 GHz (Wimax and f+1=5.25 GHz (WLAN occupies an area of 0.21λ0×0.08λ0, and two dipolar radiation patterns are obtained with comparable gains of about 6.1 and 6.2 dB, respectively. The latter antenna advances in many aspects such as an ultrasmall size of only 0.16λ0×0.08λ0, versatile radiation patterns with a monopolar pattern at f0=2.4 GHz (Bluetooth, and a dipole one at f+1=3.5 GHz (Wimax and also comparable antenna gains. Circuit parameters are extracted and researched. Excellent performances of the antennas based on hybrid resonators predict promising applications in multifunction wireless communication systems.

  13. A CPW-Fed Quasi-PIFA Antenna Using Quasi-Lumped Resonators for Mobile Phones

    Directory of Open Access Journals (Sweden)

    Majid Rafiee

    2015-01-01

    Full Text Available A novel single CPW-fed Quasi-Planar Inverted-F Antenna (PIFA using quasi-lumped elements is developed for mobile communication handheld terminals operating at 2.6 GHz. The antenna is composed of an inductor covered by a set of interdigital and parasitic capacitors. The proposed antenna achieves a measured bandwidth of 11% for return loss with the antenna gain of about 4 dBi. The antenna is designed in single layer (zero height which is appropriate to be used in thin devices where a small room is considered for the antenna. The proposed antenna is suitable for use in Long Term Evolution band 7. The operating frequency of introduced antenna depends on the number of interdigital fingers and inductor length rather than the total resonator patch only, so that the operating frequency can be altered while the total patch size remains unchanged. The calculated operating frequency is confirmed by simulation and measurement. Also the dipole-like simulated radiation pattern is confirmed by measurement.

  14. On network representations of antennas inside resonating environments

    Directory of Open Access Journals (Sweden)

    F. Gronwald

    2007-06-01

    Full Text Available We discuss network representations of dipole antennas within electromagnetic cavities. It is pointed out that for a given configuration these representations are not unique. For an efficient evaluation a network representation should be chosen such that it involves as few network elements as possible. The field theoretical analogue of this circumstance is the possibility to express electromagnetic cavities' Green's functions by representations which exhibit different convergence properties. An explicit example of a dipole antenna within a rectangular cavity clarifies the corresponding interrelation between network theory and electromagnetic field theory. As an application, current spectra are calculated for the case that the antenna is nonlinearly loaded and subject to a two-tone excitation.

  15. Detuned-resonator induced transparency in dielectric-loaded plasmonic waveguides

    DEFF Research Database (Denmark)

    Han, Zhanghua; García Ortíz, César Eduardo; Radko, Ilya P.

    2013-01-01

    We report on the experimental demonstration of detuned-resonator induced transparency in the near-infrared (∼800  nm) using two detuned racetrack resonators side-coupled to a bus waveguide. Both resonators and the bus waveguide are in the form of dielectric-loaded surface plasmon polariton...

  16. Analysis of equivalent antenna based on FDTD method

    Directory of Open Access Journals (Sweden)

    Yun-xing Yang

    2014-09-01

    Full Text Available An equivalent microstrip antenna used in radio proximity fuse is presented. The design of this antenna is based on multilayer multi-permittivity dielectric substrate which is analyzed by finite difference time domain (FDTD method. Equivalent iterative formula is modified in the condition of cylindrical coordinate system. The mixed substrate which contains two kinds of media (one of them is airtakes the place of original single substrate. The results of equivalent antenna simulation show that the resonant frequency of equivalent antenna is similar to that of the original antenna. The validity of analysis can be validated by means of antenna resonant frequency formula. Two antennas have same radiation pattern and similar gain. This method can be used to reduce the weight of antenna, which is significant to the design of missile-borne antenna.

  17. A new design of dielectric elastomer membrane resonator with tunable resonant frequencies and mode shapes

    Science.gov (United States)

    Li, Yunlong; Oh, Inkyu; Chen, Jiehao; Hu, Yuhang

    2018-06-01

    Conventional membrane resonators are bulky, and once the geometries and materials are fixed in the fabricated device, the resonators’ characteristics are fixed. In this work, we introduce the active membrane, dielectric elastomer (DE), into the resonator design. Attaching a stiffer passive membrane onto the active DE membrane forms a two-layer system, which generates an out-of-plane deformation when the DE is actuated through a DC voltage applied across the thickness of the DE membrane. When an AC voltage is applied, the two-layer system can generate an out-of-plane oscillation which enables its use as membrane resonators. Both experiments and simulations are carried out to study the dynamic characteristics of the system. The resonant frequencies and mode shapes of the resonator can be tuned through the passive layer properties such as the modulus, thickness, density, and size. The effective stiffness of the DE film changes as the magnitude of the voltage applied on the film changes, which provides an active way to tune the dynamic characteristics of the two-layer resonator even after the device is set. The system is also light weight, low cost, and easy to fabricate, and has great potential in many engineering applications.

  18. DEA deformed stretchable patch antenna

    International Nuclear Information System (INIS)

    Jiang, X-J; Jalali Mazlouman, S; Menon, C; Mahanfar, A; Vaughan, R G

    2012-01-01

    A stretchable patch antenna (SPA) whose frequency is tuned by a planar dielectric elastomer actuator (DEA) is presented in this paper. This mechanically reconfigurable antenna system has a configuration resembling a pre-stretched silicone belt. Part of the belt is embedded with a layer of conductive liquid metal to form the patch antenna. Part of the belt is sandwiched between conductive electrodes to form the DEA. Electrical activation of the DEA results in a contraction of the patch antenna, and as a result, in a variation of its resonance frequency. Design and fabrication steps of this system are presented. Measurement results for deformation, resonance frequency variation and efficiency of the patch antenna are also presented. (paper)

  19. Achieving a multi-band metamaterial perfect absorber via a hexagonal ring dielectric resonator

    Science.gov (United States)

    Li, Li-Yang; Wang, Jun; Du, Hong-Liang; Wang, Jia-Fu; Qu, Shao-Bo

    2015-06-01

    A multi-band absorber composed of high-permittivity hexagonal ring dielectric resonators and a metallic ground plate is designed in the microwave band. Near-unity absorptions around 9.785 GHz, 11.525 GHz, and 12.37 GHz are observed for this metamaterial absorber. The dielectric hexagonal ring resonator is made of microwave ceramics with high permittivity and low loss. The mechanism for the near-unity absorption is investigated via the dielectric resonator theory. It is found that the absorption results from electric and magnetic resonances where enhanced electromagnetic fields are excited inside the dielectric resonator. In addition, the resonance modes of the hexagonal resonator are similar to those of standard rectangle resonators and can be used for analyzing hexagonal absorbers. Our work provides a new research method as well as a solid foundation for designing and analyzing dielectric metamaterial absorbers with complex shapes. Project supported by the National Natural Science Foundation of China (Grant Nos. 61331005, 11204378, 11274389, 11304393, and 61302023), the Aviation Science Foundation of China (Grant Nos. 20132796018 and 20123196015), the Natural Science Foundation for Post-Doctoral Scientists of China (Grant Nos. 2013M532131 and 2013M532221), the Natural Science Foundation of Shaanxi Province, China (Grant No. 2013JM6005), and the Special Funds for Authors of Annual Excellent Doctoral Degree Dissertations of China (Grant No. 201242).

  20. A Novel T-Fed 4-Element Quasi-Lumped Resonator Antenna Array

    Directory of Open Access Journals (Sweden)

    S.S. Olokede

    2014-06-01

    Full Text Available In this paper, electrically small corporately T-fed quasi-lumped element resonator antenna array is investigated. The radiating element, a quasi-lumped element resonator is excited by a novel semi hybrid ring-like T-shaped corporate feed network. The characteristics losses due to Ohmic and discontinuities along the feed line which invariably constitutes complex feed structures are mitigated at the instance of the proposed antenna. Technique to implement the compact array with the intent to enhance the gain is presented. The operation dynamics of the feed along with its theoretical explanation is also reported. Findings indicates that the measured gain is 10.97 dBi for antenna of an estate area of about 0.677λ_0 × 1.257λ_0 sq. mm. Valuable insight to the optimum design in terms of compactness, good gain, and ease of fabrication is documented.

  1. Experimental and numerical investigation of a ceramic dielectric resonator (DRA): CaCu3Ti4O12 (CCTO)

    International Nuclear Information System (INIS)

    Almeida, A.F.L.; Silva, R.R.; Rocha, H.H.B.; Fechine, P.B.A.; Cavalcanti, F.S.A.; Valente, M.A.; Freire, F.N.A.; Sohn, R.S.T.M.

    2008-01-01

    In this study, the CaCu 3 Ti 4 O 12 (CCTO) ceramic phase was synthesized by microwave heating in a much shorter time compared to the conventional heating methods. The results indicate that microwave processing is a promising method for preparing CCTO ceramics. CCTO was prepared using a domestic microwave oven operated at 2.45 GHz with 800 W. After a few minutes of microwave irradiation the formation of CCTO was confirmed by X-ray powder diffraction. The CCTO ceramic was studied in the medium-frequency (MF) range (100 Hz-1 MHz) and in the microwave range of frequencies. The experimental and theoretical characteristics of the dielectric resonator antenna are investigated

  2. Ultrafast electron field emission from gold resonant antennas studied by two terahertz pulse experiments

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Zalkovskij, Maksim; Strikwerda, Andrew C.

    2015-01-01

    Summary form only given. Ultrafast electron field emission from gold resonant antennas induced by strong terahertz (THz) transient is investigated using two THz pulse experiments. It is shown that UV emission from nitrogen plasma generated by liberated electrons is a good indication of the local...

  3. Design of a ring resonator-based optical beam forming network for phased array receive antennas

    NARCIS (Netherlands)

    van 't Klooster, J.W.J.R.; Roeloffzen, C.G.H.; Meijerink, Arjan; Zhuang, L.; Marpaung, D.A.I.; van Etten, Wim; Heideman, Rene; Leinse, Arne; Schippers, H.; Verpoorte, J.; Wintels, M.

    2008-01-01

    A novel squint-free ring resonator-based optical beam forming network (OBFN) for phased array antennas (PAA) is proposed. It is intended to provide broadband connectivity to airborne platforms via geostationary satellites. In this paper, we present the design of the OBFN and its control system. Our

  4. Whispering-gallery-mode resonance sensor for dielectric sensing of drug tablets

    International Nuclear Information System (INIS)

    Neshat, Mohammad; Chen, Huanyu; Safavi-Naeini, Safieddin; Gigoyan, Suren; Saeedkia, Daryoosh

    2010-01-01

    We propose, for the first time, the application of whispering gallery mode (WGM) perturbation technique in dielectric analysis of disk shape pharmaceutical tablets. Based on WGM resonance, a low-cost high sensitivity sensor in milllimeter-wave frequency range is presented. A comprehensive sensitivity analysis was performed to show that a change in the order of 10 −4 in the sample permittivity can be detected by the proposed sensor. The results of various experiments carried out on drug tablets are reported to demonstrate the potential multifunctional capabilities of the sensor in moisture sensing, counterfeit drug detection and contamination screening. Analytically, two sample placement configurations, i.e. a tablet placed on top of a dielectric disk resonator and inside a dielectric ring resonator, have been studied to predict the resonance frequency and Q-factor of the combined sample-resonator structure. The accuracy of the analytical model was tested against full-wave simulations and experimental data

  5. 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

  6. Mutual Coupling Reduction of E-Shaped MIMO Antenna with Matrix of C-Shaped Resonators

    Directory of Open Access Journals (Sweden)

    Raghad Ghalib Saadallah Alsultan

    2018-01-01

    Full Text Available E-shaped multiple-input-multiple-output (MIMO microstrip antenna systems operating in WLAN and WiMAX bands (between 5 and 7.5 GHz are proposed with enhanced isolation features. The systems are comprised of two antennas that are placed parallel and orthogonal to each other, respectively. According to the simulation results, the operating frequency of the MIMO antenna system is 6.3 GHz, and mutual coupling is below −18 dB in a parallel arrangement, whereas they are 6.4 GHz and −25 dB, respectively, in the orthogonal arrangement. The 2 × 3 matrix of C-shaped resonator (CSR is proposed and placed between the antenna elements over the substrate, to reduce the mutual coupling and enhance the isolation between the antennas. More than 30 dB isolation between the array elements is achieved at the resonant frequency for both of the configurations. The essential parameters of the MIMO array such as mutual coupling, surface current distribution, envelop correlation coefficient (ECC, diversity gain (DG, and the total efficiency have been simulated to verify the reliability and the validity of the MIMO system in both parallel and orthogonal configurations. The experimental results are also provided and compared for the mutual coupling with simulated results. An adequate match between the measured and simulated results is achieved.

  7. Patch Antenna based on a Photovoltaic Cell with a Dual resonance Frequency

    Directory of Open Access Journals (Sweden)

    C. Baccouch

    2016-11-01

    Full Text Available The present work was to use photovoltaic solar cells in patch antenna structures. The radiating patch element of a patch antenna was replaced by a solar cell. Direct Current (DC generation remained the original feature of the solar cell, but additionally   it was now able to receive and transmit electromagnetic waves. Here, we used a new patch antenna structure based on a photovoltaic solar cell. It was then used to collect photo-generated current as well as Radio Frequency (RF transmission. A mathematical model which would serve the minimization of power losses of the cell and therefore the improvement in the conversion efficiency was studied. A simulation allowed analysing the performance of the antenna, with a silicon material, and testing its parameters such as the reflection coefficient (S11, gain, directivity and radiated power. The performance analysis of the solar cell patch antenna was conducted using Advanced Design System (ADS software. Simulation results for this antenna showed a dual resonance frequency of 5.77 GHz and of 6.18 GHz with an effective return loss of -38.22dB and a gain of 1.59dBi.

  8. Integration of Resonant Coil for Wireless Power Transfer and Implantable Antenna for Signal Transfer

    Directory of Open Access Journals (Sweden)

    Dong-Wook Seo

    2016-01-01

    Full Text Available We propose the integration of the resonant coil for wireless power transfer (WPT and the implantable antenna for physiological signal transfer. The integration allows for a compact biomedical implantable system such as electrocardiogram (ECG recorder and pacemaker. While the resonant coils resonate at the frequency of 13.56 MHz for the WPT, the implantable antenna works in the medical implant communications service (MICS band of 402–405 MHz for wireless communications. They share the narrow substrate area of a bar-type shape; the coil has the current path on the outer part of the substrate and the meandered planar inverted-F antenna (PIFA occupies the inside of the coil. To verify the potentials of the proposed structure, a prototype is fabricated and tested in vitro. The power transfer efficiency (PTE of about 20% is obtained at a distance of 15 mm and the antenna gain of roughly −40 dBi is achieved.

  9. Complementary Split Ring Resonator Based Triple Band Microstrip Antenna for WLAN/WiMAX Applications

    Directory of Open Access Journals (Sweden)

    W. Ali

    2017-04-01

    Full Text Available A new simple design of a triple-band microstrip antenna using metamaterial concept is presented in this paper. Multi-unit cell was the key of the multi resonance response that was obtained by etching two circular and one rectangular split ring resonator (SRR unit cells in the ground plane of a conventional patch operating at 3.56 GHz .The circular unit cells are resonating at 5.6 GHz for the upper band of Wi-MAX, while the rectangular cell is designed to produce a resonance at 2.45 GHz for the lower band of WLAN. WiMAX's/WLAN's operating bands are covered by the triple resonances which are achieved by the proposed antenna with quite enhanced performance. A detailed parametric study of the placement for the metamaterial unit cells is introduced and the most suitable positions are chosen to be the place of the unit cells for enhanced performance. A good consistency between simulation and measurement confirms the ability of the proposed antenna to achieve an improved gain at the three different frequencies.

  10. Resonances and anti-resonances in the material parameters of 2-D dielectric ENG, MNG, and DNG materials

    DEFF Research Database (Denmark)

    Wu, Yunqiu; Arslanagic, Samel

    The resonant/anti-resonant behavior of parameters extracted by the S-parameter method for two-dimensional epsilon-, mu- and double-negative (ENG, MNG, DNG) materials is investigated. The unit cells consist of infinite dielectric cylinders supporting electric dipole, magnetic dipole, or both....... It is shown that the extraction procedure yields one resonant material parameter, and one anti-resonant material parameter in MNG and ENG configurations. However, both parameters display an over-all resonant response in DNG configurations where electric and magnetic dipole modes are excited simultaneously....

  11. Antennas.

    Science.gov (United States)

    1982-03-03

    arc csch csch - 1 Russian English rot curl lg log !i FIVE-METER SPHERICAL MILLIMETER-BAND ANTENNA P.M. Geruni This article presents the basic...rlpe’ I operating band, MHz elliptical Xk, mm X , m fk, MHz z wavgudeeg MHz f =1.2f f =0.95f waegid H X B rip = E40 104.5 56.4 2872 5410 3446 5141 E48...aperture In order to do this, we expand (30) into a series with respect to y. Limiting ourselves to the first three terms of the expansion, we obtain r

  12. Precise microwave characterization of MgO substrates for HTS circuits with superconducting post dielectric resonator

    International Nuclear Information System (INIS)

    Mazierska, Janina; Ledenyov, Dimitri; Jacob, Mohan V; Krupka, Jerzy

    2005-01-01

    Accurate data of complex permittivity of dielectric substrates are needed for efficient design of HTS microwave planar circuits. We have tested MgO substrates from three different manufacturing batches using a dielectric resonator with superconducting parts recently developed for precise microwave characterization of laminar dielectrics at cryogenic temperatures. The measurement fixture has been fabricated using a SrLaAlO 3 post dielectric resonator with DyBa 2 Cu 3 O 7 end plates and silver-plated copper sidewalls to achieve the resolution of loss tangent measurements of 2 x 10 -6 . The tested MgO substrates exhibited the average relative permittivity of 9.63 and tanδ from 3.7 x 10 -7 to 2 x 10 -5 at frequency of 10.5 GHz in the temperature range from 14 to 80 K

  13. Precise microwave characterization of MgO substrates for HTS circuits with superconducting post dielectric resonator

    Energy Technology Data Exchange (ETDEWEB)

    Mazierska, Janina [Institute of Information Sciences and Technology, Massey University, Palmerston North, P. Bag 11222 (New Zealand); Ledenyov, Dimitri [Electrical and Computer Engineering, James Cook University, Townsville, Q4811 (Australia); Jacob, Mohan V [Electrical and Computer Engineering, James Cook University, Townsville, Q4811 (Australia); Krupka, Jerzy [Instytut Mikroelektroniki i Optoelektroniki Politechniki Warszawskiej, Koszykowa 75, 00-662 Warsaw (Poland)

    2005-01-01

    Accurate data of complex permittivity of dielectric substrates are needed for efficient design of HTS microwave planar circuits. We have tested MgO substrates from three different manufacturing batches using a dielectric resonator with superconducting parts recently developed for precise microwave characterization of laminar dielectrics at cryogenic temperatures. The measurement fixture has been fabricated using a SrLaAlO{sub 3} post dielectric resonator with DyBa{sub 2}Cu{sub 3}O{sub 7} end plates and silver-plated copper sidewalls to achieve the resolution of loss tangent measurements of 2 x 10{sup -6}. The tested MgO substrates exhibited the average relative permittivity of 9.63 and tan{delta} from 3.7 x 10{sup -7} to 2 x 10{sup -5} at frequency of 10.5 GHz in the temperature range from 14 to 80 K.

  14. Ion Cyclotron Resonant Heating 2 X 1700 loop antenna for the Tandem Mirror Experiment-Upgrade

    International Nuclear Information System (INIS)

    Brooksby, C.A.; Ferguson, S.W.; Molvik, A.W.; Barter, J.

    1986-01-01

    This paper reviews the mechanical design and improvements that have taken place on the loop type ion cyclotron resonance heating (ICRH) antennas that are located in the center cell region of the Tandem Mirror Experiment-Upgrade (TMX-U). A computer code (JASON) was used to design getter-shielded antenna supports that will hold off very high voltages (83 kV, DC) over a small insulator distance (2.25 inches) in a vacuum of 10/sup -5/ Torr. The authors also added corona shields on the ceramic-to-metal joints of the matching network capacitors. The system now operates reliably with peak radio frequency (RF) voltages of 40 kV at 2-to-4- MHz frequency and power levels up to 200 kW. The authors have just installed a new loop antenna in the east part of the central cell where the slot antenna was located. This antenna uses two of the slot's internal coax lines and the external matching network. The feedthroughs designed by Lawrence Livermore National Laboratory (LLNL) were replaced with two high-voltage RF feedthroughs designed by Oak Ridge National Laboratory (ORNL)

  15. Wideband RCS Reduction of Microstrip Array Antenna Based on Absorptive Frequency Selective Surface and Microstrip Resonators

    Directory of Open Access Journals (Sweden)

    Jingjing Xue

    2017-01-01

    Full Text Available An approach for wideband radar cross section (RCS reduction of a microstrip array antenna is presented and discussed. The scheme is based on the microstrip resonators and absorptive frequency selective surface (AFSS with a wideband absorptive property over the low band 1.9–7.5 GHz and a transmission characteristic at high frequency 11.05 GHz. The AFSS is designed to realize the out-of-band RCS reduction and preserve the radiation performance simultaneously, and it is placed above the antenna with the operating frequency of 11.05 GHz. Moreover, the microstrip resonators are loaded to obtain the in-band RCS reduction. As a result, a significant RCS reduction from 1.5 GHz to 13 GHz for both types of polarization has been accomplished. Compared with the reference antenna, the simulated results exhibit that the monostatic RCS of the proposed array antenna in x- and y-polarization can be reduced as much as 17.6 dB and 21.5 dB, respectively. And the measured results agree well with the simulated ones.

  16. Using low-loss phase-change materials for mid-infrared antenna resonance tuning.

    Science.gov (United States)

    Michel, Ann-Katrin U; Chigrin, Dmitry N; Maß, Tobias W W; Schönauer, Kathrin; Salinga, Martin; Wuttig, Matthias; Taubner, Thomas

    2013-08-14

    We show tuning of the resonance frequency of aluminum nanoantennas via variation of the refractive index n of a layer of phase-change material. Three configurations have been considered, namely, with the antennas on top of, inside, and below the layer. Phase-change materials offer a huge index change upon the structural transition from the amorphous to the crystalline state, both stable at room temperature. Since the imaginary part of their permittivity is negligibly small in the mid-infrared spectral range, resonance damping is avoided. We present resonance shifting to lower as well as to higher wavenumbers with a maximum shift of 19.3% and a tuning figure of merit, defined as the resonance shift divided by the full-width at half-maximum (FWHM) of the resonance peak, of 1.03.

  17. Miniaturization of body worn antenna using nano magneto-dielectric composite as substrate in C-band

    Energy Technology Data Exchange (ETDEWEB)

    Gogoi, Pragyan Jyoti; Rabha, Mun Mun [Microwave Engineering Laboratory, Department of Physics, Tezpur University, Napaam, Tezpur, Assam 784028 (India); Bhattacharyya, Satyajib [Microwave Engineering Laboratory, Department of Physics, Tezpur University, Napaam, Tezpur, Assam 784028 (India); Department of Electronics and Communication Engineering, Tezpur University, Napaam, Tezpur, Assam 784028 (India); Bhattacharyya, Nidhi S., E-mail: nidhisbhatta@gmail.com [Microwave Engineering Laboratory, Department of Physics, Tezpur University, Napaam, Tezpur, Assam 784028 (India)

    2016-09-15

    It is preferable to have small size conformal microstrip patch antenna for body worn applications. Size reduction is generally carried out by using magneto-dielectric material. Nanosized Ni{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} (x=0.25, 0.50 and 0.75) of crystallite size ~32 nm is synthesized as magnetic filler and dispersed in flexible linear low density polyethylene (LLDPE) matrix. The filler concentrations are varied as 1, 3, 5 and 7 wt% in the composite. The developed composite is tested for suitability to be used as substrate for microstrip antenna by determining its permittivity, permeability and losses in the C-band (4–8 GHz). Other relevant parameters like, tensile strength, water absorbance and decomposition temperature of the composite are also determined. The real part of complex permittivity of the composite varies from 2.23 to 2.38 and complex permeability from 1.25 to 1.46 for different filler concentrations. Verification of the composites as potential substrates for body worn antenna is carried out by fabricating simple rectangular patch antenna at 6 GHz on it using transmission line model. Rectangular patch for x=0.50 for 7 wt% shows S{sub 11} of −30.44 dB and −10 dB bandwidth of 8.30% at 6.02 GHz. Directivity of 10.14 dBi and negligible side lobe level for both E and H plane radiation pattern is observed. A size reduction of 27.09% as compared to patch on LLDPE and tensile strength of 50 MPa is observed. - Highlights: • Nickel zinc ferrite-LLDPE composite is developed as substrate for body worn antennas. • Its suitability is determined by physical, thermal and microwave characterization. • S{sub 11} of -31.44 dB and -10 dB BW of 8.30% is observed for 7 wt% NZF-LLDPE composite.

  18. First test of a BAE transducing scheme on a Resonant Gravitational-Wave Antenna

    International Nuclear Information System (INIS)

    Bonifazi, P.; Vaselli, V.; Visco, M.

    1997-01-01

    The authors present the results obtained with a resonant capacitive transducer, suitable for Back Action Evasion (BAE) measurements, coupled for the first time to a gravitational-wave antenna. This scheme was developed in collaboration with the Group of the University of Rome La Sapienza. The antenna is a 270 kg aluminum 5056 alloy cylinder, with a resonant frequency of 1805 Hz, operating at 4.2 K in the ALTAIR cryostat, located in Frascati (Italy) at the IFSI-CNR laboratory. The apparatus was able to work for periods as long as days, both in up-conversion and BAE configurations, with good stability. The behaviour of the system is in reasonable agreement with a proposed model of a double harmonic oscillator in a BAE readout scheme. The limits on the sensitivity of this set-up are discussed as well as the possible future improvements

  19. Light Scattering by a Dielectric Sphere: Perspectives on the Mie Resonances

    Directory of Open Access Journals (Sweden)

    Dimitrios Tzarouchis

    2018-01-01

    Full Text Available Light scattering by a small spherical particle, a central topic for electromagnetic scattering theory, is here considered. In this short review, some of the basic features of its resonant scattering behavior are covered. First, a general physical picture is described by a full electrodynamic perspective, the Lorenz–Mie theory. The resonant spectrum of a dielectric sphere reveals the existence of two distinctive types of polarization enhancement: the plasmonic and the dielectric resonances. The corresponding electrostatic (Rayleigh picture is analyzed and the polarizability of a homogeneous spherical inclusion is extracted. This description facilitates the identification of the first type of resonance, i.e., the localized surface plasmon (plasmonic resonance, as a function of the permittivity. Moreover, the electrostatic picture is linked with the plasmon hybridization model through the case of a step-inhomogeneous structure, i.e., a core–shell sphere. The connections between the electrostatic and electrodynamic models are reviewed in the small size limit and details on size-induced aspects, such as the dynamic depolarization and the radiation reaction on a small sphere are exposed through the newly introduced Mie–Padé approximative perspective. The applicability of this approximation is further expanded including the second type of resonances, i.e., the dielectric resonances. For this type of resonances, the Mie–Padé approximation reveals the main character of the two different cases of resonances of either magnetic or electric origin. A unified picture is therefore described encompassing both plasmonic and dielectric resonances, and the resonant conditions of all three different types are extracted as functions of the permittivity and the size of the sphere. Lastly, the directional scattering behavior of the first two dielectric resonances is exposed in a simple manner, namely the Kerker conditions for maximum forward and

  20. On the Control of Surface Waves in Integrated Antennas : Analysis and Design Exploiting Artificial Dielectric Layers

    NARCIS (Netherlands)

    Syed, W.H.

    2015-01-01

    Planar printed antenna technologies, due to their light weight, low profile, cost effectiveness and ease of connection with the active devices (e.g., amplifiers etc.), are becoming an attractive solution for the commercial data-hungry applications, such as 60 GHz high-data rate communication.

  1. All-dielectric metamaterial frequency selective surface based on spatial arrangement ceramic resonators

    Science.gov (United States)

    Li, Liyang; Wang, Jun; Feng, Mingde; Ma, Hua; Wang, Jiafu; Du, Hongliang; Qu, Shaobo

    In this paper, we demonstrate a method of designing all-dielectric metamaterial frequency selective surface (FSS) with ceramic resonators in spatial arrangement. Compared with the traditional way, spatial arrangement provides a flexible way to handle the permutation and combination of different ceramic resonators. With this method, the resonance response can be adjusted easily to achieve pass/stop band effects. As an example, a stop band spatial arrangement all-dielectric metamaterial FSS is designed. Its working band is in 11.65-12.23GHz. By adjusting permittivity and geometrical parameters of ceramic resonators, we can easily modulate the resonances, band pass or band stop characteristic, as well as the working band.

  2. Ka Band Phase Locked Loop Oscillator Dielectric Resonator Oscillator for Satellite EHF Band Receiver

    Directory of Open Access Journals (Sweden)

    S. Coco

    2008-01-01

    Full Text Available This paper describes the design and fabrication of a Ka Band PLL DRO having a fundamental oscillation frequency of 19.250 GHz, used as local oscillator in the low-noise block of a down converter (LNB for an EHF band receiver. Apposite circuital models have been created to describe the behaviour of the dielectric resonator and of the active component used in the oscillator core. The DRO characterization and measurements have shown very good agreement with simulation results. A good phase noise performance is obtained by using a very high Q dielectric resonator.

  3. Mode selection in two-dimensional Bragg resonators based on planar dielectric waveguides

    International Nuclear Information System (INIS)

    Baryshev, V R; Ginzburg, N S; Zaslavskii, V Yu; Malkin, A M; Sergeev, A S; Thumm, M

    2009-01-01

    Two-dimensional Bragg resonators based on planar dielectric waveguides are analysed. It is shown that the doubly periodic corrugation deposited on the dielectric surface in the form of two gratings with translational vectors directed perpendicular to each other ensures effective selection of modes along two coordinates at large Fresnel parameters. This result is obtained both by the method of coupled waves (geometrical optics approximation) and by the direct numerical simulations. Two-dimensional Bragg resonators make it possible to fabricate two-dimensional distributed feedback lasers and to provide generation of spatially coherent radiation in large-volume active media. (waveguides)

  4. Advantages of traveling wave resonant antennas for fast wave heating systems

    International Nuclear Information System (INIS)

    Phelps, D.A.; Callis, R.W.; Grassie, J.S. de

    1997-04-01

    The resilience of a maximally flat externally coupled traveling wave antenna (TWA) is contrasted with the sensitivity of a simple directly driven resonant loop array to vacuum and plasma conditions in DIII-D. We find a unique synergy between standing and traveling wave resonant TWA components. This synergy extends TWA operation to several passbands between 60 and 120 MHZ, provides 60 degrees- 120 degrees tunability between elements within a 1-2 MHZ bandwidth and permits efficient and continuous operation during ELMing H-mode

  5. Wireless passive polymer-derived SiCN ceramic sensor with integrated resonator/antenna

    Science.gov (United States)

    Li, Yan; Yu, Yuxi; San, Haisheng; Wang, Yansong; An, Linan

    2013-10-01

    This paper presents a passive wireless polymer-derived silicon carbonitride (SiCN) ceramic sensor based on cavity radio frequency resonator together with integrated slot antenna. The effect of the cavity sensor dimensions on the Q-factor and resonant frequency is investigated by numerical simulation. A sensor with optimal dimensions is designed and fabricated. It is demonstrated that the sensor signal can be wirelessly detected at distances up to 20 mm. Given the high-temperature stability of the SiCN, the sensor is very promising for high-temperature wireless sensing applications.

  6. Microstrip patch antenna for simultaneous strain and temperature sensing

    Science.gov (United States)

    Mbanya Tchafa, F.; Huang, H.

    2018-06-01

    A patch antenna, consisting of a radiation patch, a dielectric substrate, and a ground plane, resonates at distinct fundamental frequencies that depend on the substrate dielectric constant and the dimensions of the radiation patch. Since these parameters change with the applied strain and temperature, this study investigates simultaneous strain and temperature sensing using a single antenna that has two fundamental resonant frequencies. The theoretical relationship between the antenna resonant frequency shifts, the temperature, and the applied strain was first established to guide the selection of the dielectric substrate, based on which an antenna sensor with a rectangular radiation patch was designed and fabricated. A tensile test specimen instrumented with the antenna sensor was subjected to thermo-mechanical tests. Experiment results validated the theoretical predictions that the normalized antenna resonant frequency shifts are linearly proportional to the applied strain and temperature changes. An inverse method was developed to determine the strain and temperature changes from the normalized antenna resonant frequency shifts, yielding measurement uncertainty of 0.4 °C and 17.22 μ \\varepsilon for temperature and strain measurement, respectively.

  7. Small inductor Loaded mobile phone Antenna

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2004-01-01

    In this paper a size reduction technique of the Planar Inverted F Antenna (PIFA) is presented. Using an 18 nH lumped inductor in addition to a small 0.3 cm3 PIFA located on a 5 mm thick dielectric foam above a 40 x 100 mm2 ground plane it is possible to reduce the resonant frequency by 33 % for a...

  8. Tuning Infrared Plasmon Resonance of Black Phosphorene Nanoribbon with a Dielectric Interface.

    Science.gov (United States)

    Debu, Desalegn T; Bauman, Stephen J; French, David; Churchill, Hugh O H; Herzog, Joseph B

    2018-02-19

    We report on the tunable edge-plasmon-enhanced absorption of phosphorene nanoribbons supported on a dielectric substrate. Monolayer anisotropic black phosphorous (phosphorene) nanoribbons are explored for light trapping and absorption enhancement on different dielectric substrates. We show that these phosphorene ribbons support infrared surface plasmons with high spatial confinement. The peak position and bandwidth of the calculated phosphorene absorption spectra are tunable with low loss over a wide wavelength range via the surrounding dielectric environment of the periodic nanoribbons. Simulation results show strong edge plasmon modes and enhanced absorption as well as a red-shift of the peak resonance wavelength. The periodic Fabry-Perot grating model was used to analytically evaluate the absorption resonance arising from the edge of the ribbons for comparison with the simulation. The results show promise for the promotion of phosphorene plasmons for both fundamental studies and potential applications in the infrared spectral range.

  9. All-dielectric KTiOPO4 metasurfaces based on multipolar resonances in the terahertz region

    DEFF Research Database (Denmark)

    Tian, Jingyi; Yang, Yuanqing; Qiu, Min

    2017-01-01

    We employ ferroelectrics to study the multipolar scattering in all-dielectric metasurfaces based on KTiOPO4 (KTP) micro-disks for efficient manipulation of electromagnetic waves in the THz spectral region (0.6-1.5 THz). By adjusting the aspect ratio of the disks near the multipolar resonances, we...

  10. Experimental characterization of dielectric-loaded plasmonic waveguide-racetrack resonators at near-infrared wavelengths

    DEFF Research Database (Denmark)

    Garcia, Cesar; Coello, Victor; Han, Zhanghua

    2012-01-01

    Dielectric-loaded plasmonic waveguide-racetrack resonators (WRTRs) were designed and fabricated for operating at near-infrared wavelengths (750–850 nm) and characterized using leakage-radiation microscopy. The transmission spectra of the WRTRs are found experimentally and compared to the calculat...

  11. Experimental and Theoretical Researches of a Resonator Concept of a Dielectric Wakefield Accelerator

    International Nuclear Information System (INIS)

    Onishchenko, I.N.; Kiselev, V.A.; Linnik, A.F.; Onishchenko, N.I.; Sotnikov, G.V.; Uskov, V.V.

    2006-01-01

    Wakefield excitation in a cylindrical dielectric waveguide or resonator by a regular sequence of electron bunches foe application to high-gradient particle acceleration has been investigated theoretically and experimentally using an electron linac 'ALMAZ-2' (4.5 MeV, 6.10 3 bunches of duration 60 ps and charge 0.32 nC each)

  12. Materials tests and analyses of Faraday shield tubes for ICRF [ion cyclotron resonant frequency] antennas

    International Nuclear Information System (INIS)

    King, J.F.; Baity, F.W.; Hoffman, D.J.; Walls, J.C.; Taylor, D.J.

    1988-01-01

    The ion cyclotron resonant frequency (ICRF) antennas for heating fusion plasmas require careful analysis of the materials selected for the design and the successful fabrication of high integrity braze bonds. Graphite tiles are brazed to Inconel 625 Faraday shield tubes to protect the antenna from the plasma. The bond between the graphite and Inconel tube is difficult to achieve due to the different coefficients of thermal expansion. A 2-D stress analysis showed the graphite could be bonded to Inconel with a Ag-Cu-Ti braze alloy without cracking the graphite. Brazing procedures and nondestructive examination methods have been developed for these joints. This paper presents the results of our joining development and proof testing. 2 refs., 3 figs

  13. Multiband Split-Ring Resonator Based Planar Inverted-F Antenna for 5G Applications

    Directory of Open Access Journals (Sweden)

    Muhammad Kamran Ishfaq

    2017-01-01

    Full Text Available 5G, the fifth generation of wireless communications, is focusing on multiple frequency bands, such as 6 GHz, 10 GHz, 15 GHz, 28 GHz, and 38 GHz, to achieve high data rates up to 10 Gbps or more. The industry demands multiband antennas to cover these distant frequency bands, which is a task much more challenging. In this paper, we have designed a novel multiband split-ring resonator (SRR based planar inverted-F antenna (PIFA for 5G applications. It is composed of a PIFA, an inverted-L parasitic element, a rectangular shaped parasitic element, and a split-ring resonator (SRR etched on the top plate of the PIFA. The basic PIFA structure resonates at 6 GHz. An addition of a rectangular shaped parasitic element produces a resonance at 15 GHz. The introduction of a split-ring resonator produces a band notch at 8 GHz, and a resonance at 10 GHz, while the insertion of an inverted-L shaped parasitic element further enhances the impedance bandwidth in the 10 GHz band. The frequency bands covered, each with more than 1 GHz impedance bandwidth, are 6 GHz (5–7 GHz, 10 GHz (9–10.8 GHz, and 15 GHz (14-15 GHz, expected for inclusion in next-generation wireless communications, that is, 5G. The design is simulated using Ansys Electromagnetic Suite 17 simulation software package. The simulated and the measured results are compared and analyzed which are generally in good agreement.

  14. Nano-polarization-converter based on magnetic plasmon resonance excitation in an L-shaped slot antenna.

    Science.gov (United States)

    Yang, Jing; Zhang, Jiasen

    2013-04-08

    We propose a nano-polarization-converter made of a resonant L-shaped slot antenna in a gold film and study its optical properties using the finite-difference time-domain method. Phase retardation between the fast and slow axes of the nano-polarization-converter originates from the simultaneous excitation of both single-surface first-order magnetic plasmon resonance mode and second-order magnetic plasmon resonance mode at the working wavelength. By adjusting the size of the slot antenna, which is still much smaller than the wavelength, the working wavelength can be tuned within a large wavelength range.

  15. Ellipsoidal all-dielectric Fano resonant core-shell metamaterials

    Science.gov (United States)

    Reena, Reena; Kalra, Yogita; Kumar, Ajeet

    2018-06-01

    In this paper, ellipsoidal core (Si) and shell (SiO2) metamaterial has been proposed for highly directional properties. At the wavelength of magnetic resonance, Fano dip occurs in the backward scattering cross section and forward scattering enhancement takes place at the same wavelength so that there is an increment in the directivity. Effect on the directivity by changing the length of ellipsoidal nanoparticle along semi-axes has been analyzed. Two Fano resonances have been observed by decreasing the length of the nanoparticle along the semi-axis having electric polarization, where first and second Fano resonances are attributed to the dipole and quadrupole moments, respectively. These Fano resonant wavelengths in ellipsoidal nanoparticle exhibit higher directivity than the Kerker's type scattering or forward scattering shown by symmetrical structures like sphere. So, this core-shell metamaterial can act as an efficient directional nanoantenna.

  16. Construction of a resonant loop with the ICRF antenna for KSTAR

    International Nuclear Information System (INIS)

    Bae, Young Dug; Jeong, Sung Un; Yoon, Jae Sung; Hong, Bong Geon

    2003-01-01

    The antenna of the KSTAR ICRF heating system consists of four current straps, each of which is grounded at the center, and has two coaxial ports, one at each end. The top and bottom ports of each strap are fed by one transmitter. The two ports are connected at tee connector to form a resonant loop, and the coaxial feed line from the transmitter is connected to the tee. One resonant loop with the proto-type antenna is built at the RF test stand in KAERI. It is composed with one current strap, one tee connector and two arms connecting them. Each arm consists of a 6-inch vacuum transmission line, a vacuum feed through, a part of pressurized 9-inch coaxial line, and an adjustable phase shifter to cover wide frequency range of 25-60 MHz. Total electrical length is changeable from 45 to 51 m. Many voltage probes and directional couplers are installed to measure RF voltage of the standing wave, power flow and phase difference. Resonant and matching conditions are investigated for various frequencies

  17. Investigations of Relatively Easy To Construct Antennas With Efficiency in Receiving Schumann Resonances: Preparations for a Miniaturized Reconfigurable ELF Receiver

    Science.gov (United States)

    Farmer, Brian W.; Hannan, Robert C.

    2003-01-01

    Relatively little is known about the cavity between the Earth and the ionosphere, which opens opportunities for technological advances and unique ideas. One effective means to study this cavity is with extremely low frequency (ELF) antennas. Possible applications of these antennas are global weather prediction, earthquake prediction, planetary exploration, communication, wireless transmission of power, or even a free energy source. The superconducting quantum interference device SQUID) and the coil antenna are the two most acceptable receivers discovered for picking up ELF magnetic fields. Both antennas have the potential for size reduction, allowing them to be portable enough for access to space and even for personal ware. With improvements of these antennas and signal processing, insightful analysis of Schumann resonance (SR) can give the science community a band of radio frequency (RF) signals for improving life here on Earth and exploring beyond.

  18. Measurements of the anomalous RF surface resistance of niobium using a dielectric resonator

    International Nuclear Information System (INIS)

    Moffat, D.; Bolore, M.; Bonin, B.; Jacques, E.; Safa, H.

    1996-01-01

    The surface resistance of high and low residual resistance ratio (RRR) niobium plates at 4.2 K and 1.8 K has been measured as a function of many processing and testing parameters. A dielectric resonator was used instead of a resonant cavity. This resonator offered the ability to make many, sensitive measurements with an efficient use of time and helium. It was found that the surface resistance, R s , of RRR = 190 niobium increased noticeably from the theoretical value if the cooling rate was slower than ∼ 10 K/min. (author)

  19. Multi-layered dielectric cladding plasmonic microdisk resonator filter and coupler

    International Nuclear Information System (INIS)

    Han Cheng, Bo; Lan, Yung-Chiang

    2013-01-01

    This work develops the plasmonic microdisk filter/coupler, whose effectiveness is evaluated by finite-difference time-domain simulation and theoretical analyses. Multi-layer dielectric cladding is used to prevent the scattering of surface plasmons (SPs) from a silver microdisk. This method allows devices that efficiently perform filter/coupler functions to be developed. The resonant conditions and the effective refractive index of bounded SP modes on the microdisk are determined herein. The waveguide-to-microdisk distance barely influences the resonant wavelength but it is inversely related to the bandwidth. These findings are consistent with predictions made using the typical ring resonator model.

  20. Two-Element Tapered Slot Antenna Array for Terahertz Resonant Tunneling Diode Oscillators

    Directory of Open Access Journals (Sweden)

    Jianxiong Li

    2014-01-01

    Full Text Available Two-element tapered slot antenna (TSA array for terahertz (THz resonant tunneling diode (RTD oscillators is proposed in this paper. The proposed TSA array has the advantages of both the high directivity and high gain at the horizontal direction and hence can facilitate the horizontal communication between the RTD oscillators and other integrated circuit chips. A MIM (metal-insulator-metal stub with a T-shaped slot is used to reduce the mutual coupling between the TSA elements. The validity and feasibility of the proposed TSA array have been simulated and analyzed by the ANSYS/ANSOFT’s High Frequency Structure Simulator (HFSS. Detailed modeling approaches and theoretical analysis of the proposed TSA array have been fully addressed. The simulation results show that the mutual coupling between the TSA elements is reduced below −40 dB. Furthermore, at 500 GHz, the directivity, the gain, and the half power beam width (HPBW at the E-plane of the proposed TSA array are 12.18 dB, 13.09 dB, and 61°, respectively. The proposed analytical method and achieved performance are very promising for the antenna array integrated with the RTD oscillators at the THz frequency and could pave the way to the design of the THz antenna array for the RTD oscillators.

  1. Wideband and UWB Antennas for Wireless Applications: A Comprehensive Review

    Directory of Open Access Journals (Sweden)

    Renato Cicchetti

    2017-01-01

    Full Text Available A comprehensive review concerning the geometry, the manufacturing technologies, the materials, and the numerical techniques, adopted for the analysis and design of wideband and ultrawideband (UWB antennas for wireless applications, is presented. Planar, printed, dielectric, and wearable antennas, achievable on laminate (rigid and flexible, and textile dielectric substrates are taken into account. The performances of small, low-profile, and dielectric resonator antennas are illustrated paying particular attention to the application areas concerning portable devices (mobile phones, tablets, glasses, laptops, wearable computers, etc. and radio base stations. This information provides a guidance to the selection of the different antenna geometries in terms of bandwidth, gain, field polarization, time-domain response, dimensions, and materials useful for their realization and integration in modern communication systems.

  2. Circuit model optimization of a nano split ring resonator dimer antenna operating in infrared spectral range

    International Nuclear Information System (INIS)

    Gneiding, N.; Zhuromskyy, O.; Peschel, U.; Shamonina, E.

    2014-01-01

    Metamaterials are comprised of metallic structures with a strong response to incident electromagnetic radiation, like, for example, split ring resonators. The interaction of resonator ensembles with electromagnetic waves can be simulated with finite difference or finite elements algorithms, however, above a certain ensemble size simulations become inadmissibly time or memory consuming. Alternatively a circuit description of metamaterials, a well developed modelling tool at radio and microwave frequencies, allows to significantly increase the simulated ensemble size. This approach can be extended to the IR spectral range with an appropriate set of circuit element parameters accounting for physical effects such as electron inertia and finite conductivity. The model is verified by comparing the coupling coefficients with the ones obtained from the full wave numerical simulations, and used to optimize the nano-antenna design with improved radiation characteristics.

  3. Antennas in inhomogeneous media

    CERN Document Server

    Galejs, Janis; Fock, V A; Wait, J R

    2013-01-01

    Antennas in Inhomogeneous Media details the methods of analyzing antennas in such inhomogeneous media. The title covers the complex geometrical configurations along with its variational formulations. The coverage of the text includes various conditions the antennas are subjected to, such as antennas in the interface between two media; antennas in compressible isotropic plasma; and linear antennas in a magnetoionic medium. The selection also covers insulated loops in lossy media; slot antennas with a stratified dielectric or isotropic plasma layers; and cavity-backed slot antennas. The book wil

  4. Analysis of specular resonance in dielectric bispheres using rigorous and geometrical-optics theories.

    Science.gov (United States)

    Miyazaki, Hideki T; Miyazaki, Hiroshi; Miyano, Kenjiro

    2003-09-01

    We have recently identified the resonant scattering from dielectric bispheres in the specular direction, which has long been known as the specular resonance, to be a type of rainbow (a caustic) and a general phenomenon for bispheres. We discuss the details of the specular resonance on the basis of systematic calculations. In addition to the rigorous theory, which precisely describes the scattering even in the resonance regime, the ray-tracing method, which gives the scattering in the geometrical-optics limit, is used. Specular resonance is explicitly defined as strong scattering in the direction of the specular reflection from the symmetrical axis of the bisphere whose intensity exceeds that of the scattering from noninteracting bispheres. Then the range of parameters for computing a particular specular resonance is specified. This resonance becomes prominent in a wide range of refractive indices (from 1.2 to 2.2) in a wide range of size parameters (from five to infinity) and for an arbitrarily polarized light incident within an angle of 40 degrees to the symmetrical axis. This particular scattering can stay evident even when the spheres are not in contact or the sizes of the spheres are different. Thus specular resonance is a common and robust phenomenon in dielectric bispheres. Furthermore, we demonstrate that various characteristic features in the scattering from bispheres can be explained successfully by using intuitive and simple representations. Most of the significant scatterings other than the specular resonance are also understandable as caustics in geometrical-optics theory. The specular resonance becomes striking at the smallest size parameter among these caustics because its optical trajectory is composed of only the refractions at the surfaces and has an exceptionally large intensity. However, some characteristics are not accounted for by geometrical optics. In particular, the oscillatory behaviors of their scattering intensity are well described by

  5. A hollow coaxial cable Fabry-Pérot resonator for liquid dielectric constant measurement

    Science.gov (United States)

    Zhu, Chen; Zhuang, Yiyang; Chen, Yizheng; Huang, Jie

    2018-04-01

    We report, for the first time, a low-cost and robust homemade hollow coaxial cable Fabry-Pérot resonator (HCC-FPR) for measuring liquid dielectric constant. In the HCC design, the traditional dielectric insulating layer is replaced by air. A metal disk is welded onto the end of the HCC serving as a highly reflective reflector, and an open cavity is engineered on the HCC. After the open cavity is filled with the liquid analyte (e.g., water), the air-liquid interface acts as a highly reflective reflector due to large impedance mismatch. As a result, an HCC-FPR is formed by the two highly reflective reflectors, i.e., the air-liquid interface and the metal disk. We measured the room temperature dielectric constant for ethanol/water mixtures with different concentrations using this homemade HCC-FPR. Monitoring the evaporation of ethanol in ethanol/water mixtures was also conducted to demonstrate the ability of the sensor for continuously monitoring the change in dielectric constant. The results revealed that the HCC-FPR could be a promising evaporation rate detection platform with high performance. Due to its great advantages, such as high robustness, simple configuration, and ease of fabrication, the novel HCC-FPR based liquid dielectric constant sensor is believed to be of high interest in various fields.

  6. All-dielectric resonant cavity-enabled metals with broadband optical transparency

    Science.gov (United States)

    Liu, Zhengqi; Zhang, Houjiao; Liu, Xiaoshan; Pan, Pingping; Liu, Yi; Tang, Li; Liu, Guiqiang

    2017-06-01

    Metal films with broadband optical transparency are desirable in many optoelectronic devices, such as displays, smart windows, light-emitting diodes and infrared detectors. As bare metal is opaque to light, this issue of transparency attracts great scientific interest. In this work, we proposed and demonstrated a feasible and universal approach for achieving broadband optical transparent (BOT) metals by utilizing all-dielectric resonant cavities. Resonant dielectrics provide optical cavity modes and couple strongly with the surface plasmons of the metal film, and therefore produce a broadband near-unity optical transparent window. The relative enhancement factor (EF) of light transmission exceeds 3400% in comparison with that of pure metal film. Moreover, the transparent metal motif can be realized by other common metals including gold (Au), silver (Ag) and copper (Cu). These optical features together with the fully retained electric and mechanical properties of a natural metal suggest that it will have wide applications in optoelectronic devices.

  7. Resonant photon tunneling via surface plasmon polaritons through one-dimensional metal-dielectric metamaterials

    OpenAIRE

    Tomita, Satoshi; Yokoyama, Takashi; Yanagi, Hisao; Wood, Ben; Pendry, John B.; Fujii, Minoru; Hayashi, Shinji

    2008-01-01

    We report resonant photon tunneling (RPT) through onedimensional metamaterials consisting of alternating layers of metal and dielectric. RPT via a surface plasmon polariton state permits evanescent light waves with large wavenumbers to be conveyed through the metamaterial. This is the mechanism for sub-wavelength imaging recently demonstrated with a super-lens. Furthermore, we find that the RPT peak is shifted from the reflectance dip with increasing the number of Al layers, indicating that t...

  8. An electromagnetic induced transparency-like scheme for wireless power transfer using dielectric resonators

    Science.gov (United States)

    Elnaggar, Sameh Y.

    2017-02-01

    Similar to the hybridization of three atoms, three coupled resonators interact to form bonding, anti-bonding, and non-bonding modes. The non-bonding mode enables an electromagnetic induced transparency like transfer of energy. Here, the non-bonding mode, resulting from the strong electric coupling of two dielectric resonators and an enclosure, is exploited to show that it is feasible to transfer power over a distance comparable to the operating wavelength. In this scheme, the enclosure acts as a mediator. The strong coupling permits the excitation of the non-bonding mode with high purity. This approach is different from resonant inductive coupling, which works in the sub-wavelength regime. Optimal loads and the corresponding maximum efficiency are determined using two independent methods: Coupled Mode Theory and Circuit modelling. It is shown that, unlike resonant inductive coupling, the figure of merit depends on the enclosure quality and not on the load, which emphasizes the role of the enclosure as a mediator. Briefly after the input excitation is turned on, the energy in the receiver builds up via all coupled and spurious modes. As time elapses, all modes except the non-bonding cease to sustain. Due to the strong coupling between the dielectrics and the enclosure, such systems have unique properties such as high and uniform efficiency over large distances and minimal fringing fields. These properties suggest that electromagnetic induced transparency like schemes that rely on the use of dielectric resonators can be used to power autonomous systems inside an enclosure or find applications when exposure to the fields needs to be minimal. Finite Element computations are used to verify the theoretical predictions by determining the transfer efficiency, field profile, and coupling coefficients for two different systems. It is shown that the three resonators must be present for efficient power transfer; if one or more are removed, the transfer efficiency reduces

  9. Electron waves and resonances in bounded plasmas

    CERN Document Server

    Vandenplas, Paul E

    1968-01-01

    General theoretical methods and experimental techniques ; the uniform plasma slab-condenser system ; the hollow cylindrical plasma ; scattering of a plane electromagnetic wave by a plasma column in steady magnetic fields (cold plasma approximation) ; hot non-uniform plasma column ; metallic and dielectric resonance probes, plasma-dielectric coated antenna, general considerations.

  10. Design of a Label-Free, Distributed Bragg Grating Resonator Based Dielectric Waveguide Biosensor

    Directory of Open Access Journals (Sweden)

    Florian Kehl

    2015-01-01

    Full Text Available In this work, we present a resonant, dielectric waveguide device based on distributed Bragg gratings for label-free biosensing applications. The refractive index sensitive optical transducer aims at improving the performance of planar waveguide grating sensor systems with limited Q-factor and dynamic range by combing the advantages of resonant cavities, such as a multitude of resonance peaks with high finesse, with the manageable complexity of waveguide grating couplers. The general sensor concept is introduced and supported by theoretical considerations as well as numerical simulations based on Coupled Mode Theory. In contrast to a single Bragg grating reflector, the presented Fabry-Pérot type distributed Bragg resonator exhibits an extended measurement range as well as relaxed fabrication tolerances. The resulting, relatively simple sensor structure can be fabricated with standard lithographic means and is independent of expensive light-sources and/or detectors, making an affordable but sensitive device, potentially suitable for point-of-care applications.

  11. Resonant frequencies and Q factors of dielectric parallelepipeds by measurement and by FDTD

    Energy Technology Data Exchange (ETDEWEB)

    Trueman, C.W. [Concordia Univ., Montreal, Quebec (Canada); Mishra, S.R.; Larose, C.L. [David Florida Lab., Ottawa (Canada)] [and others

    1994-12-31

    This paper describes the measurement and computation of the resonant frequencies and the associated Q factors of dielectric parallelepipeds made of high-permittivity, low-loss ceramic materials. Each resonance peak is measured separately with a fine frequency step. A curve-fitting method is used to accurately estimate the resonant frequency and 3 dB bandwidth from the somewhat noisy measured data. The finite-difference time-domain method is used to compute the initial portion of the backscattered field due to a Gaussian pulse plane wave. The time response is then extended to zero value by Prony`s method. The measured and computed data is compared for a parallelepiped resonator of permittivity 37.84.

  12. Symposium KK, Resonant Optics in Dielectric and Metallic Structures: Fundamentals and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Larouche, Stephane [Duke Univ., Durham, NC (United States); Caldwell, Joshua [Naval Research Lab. (NRL), Washington, DC (United States)

    2016-09-06

    Symposium KK focused on the design, fabrication, characterization of novel nanoscale optical resonators and alternative materials for sub-diffraction scale resonant particles. Contributions discussed all aspects of this field, and the organizers had more than 130 contributing participants to this session alone, spanning North America, Europe, Asia and Australia. Participants discussed cutting edge research results focused on the structure, physical and optical properties, and ultrafast dynamic response of nanoscale resonators such as plasmonic and dielectric nanoparticles. A strong focus on state-of-the-art characterization and fabrication approaches, as well as presentations on novel materials for sub-diffraction resonators took place. As expected, the sessions provided strong interdisciplinary interactions and lively debate among presenters and participants.

  13. Characterization of a dielectric phantom for high-field magnetic resonance imaging applications

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Qi, E-mail: Qi.Duan@nih.gov; Duyn, Jeff H.; Gudino, Natalia; Zwart, Jacco A. de; Gelderen, Peter van [Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892 (United States); Sodickson, Daniel K.; Brown, Ryan [The Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York 10016 (United States)

    2014-10-15

    Purpose: In this work, a generic recipe for an inexpensive and nontoxic phantom was developed within a range of biologically relevant dielectric properties from 150 MHz to 4.5 GHz. Methods: The recipe includes deionized water as the solvent, NaCl to primarily control conductivity, sucrose to primarily control permittivity, agar–agar to gel the solution and reduce heat diffusivity, and benzoic acid to preserve the gel. Two hundred and seventeen samples were prepared to cover the feasible range of NaCl and sucrose concentrations. Their dielectric properties were measured using a commercial dielectric probe and were fitted to a 3D polynomial to generate a recipe describing the properties as a function of NaCl concentration, sucrose concentration, and frequency. Results: Results indicated that the intuitive linear and independent relationships between NaCl and conductivity and between sucrose and permittivity are not valid. A generic polynomial recipe was developed to characterize the complex relationship between the solutes and the resulting dielectric values and has been made publicly available as a web application. In representative mixtures developed to mimic brain and muscle tissue, less than 2% difference was observed between the predicted and measured conductivity and permittivity values. Conclusions: It is expected that the recipe will be useful for generating dielectric phantoms for general magnetic resonance imaging (MRI) coil development at high magnetic field strength, including coil safety evaluation as well as pulse sequence evaluation (including B{sub 1}{sup +} mapping, B{sub 1}{sup +} shimming, and selective excitation pulse design), and other non-MRI applications which require biologically equivalent dielectric properties.

  14. Study on guided-mode resonance characteristic of multilayer dielectric grating with broadband and wide using-angle

    International Nuclear Information System (INIS)

    Jian-Peng, Wang; Yun-Xia, Jin; Jian-Yong, Ma; Jian-Da, Shao; Zheng-Xiu, Fan

    2010-01-01

    Guided-mode resonance in a diffraction band of multilayer dielectric gratings may lead to a catastrophic result in laser system, especially in the ultrashort pulse laser system, so the inhibition of guided-mode resonance is very important. In this paper the characteristics of guided-mode resonance in multilayer dielectric grating are studied with the aim of better understanding the physical process of guided-mode resonance and designing a broadband multilayer dielectric grating with no guided-mode resonance. By employing waveguide theory, all guided-wave modes appearing in multilayer dielectric grating are found, and the incident conditions, separately, corresponding to each guided-wave mode are also obtained. The electric field enhancement in multilayer dielectric grating is shown obviously. Furthermore, from the detailed analyses on the guided-mode resonance conditions, it is found that the reduction of the grating period would effectively avoid the appearing of guided-mode resonance. And the expressions for calculating maximum periods, which ensure that no guided-mode resonance occurs in the requiring broad angle or wavelength range, are first reported. The above results calculated by waveguide theory and Fourier mode method are compared with each other, and they are coincident completely. Moreover, the method that relies on waveguide theory is more helpful for understanding the guided-mode resonance excited process and analyzing how each parameter affects the characteristic of guided-mode resonance. Therefore, the effects of multilayer dielectric grating parameters, such as period, fill factor, thickness of grating layer, et al., on the guided-mode resonance characteristic are discussed in detail based on waveguide theory, and some meaningful results are obtained. (classical areas of phenomenology)

  15. Superluminal antenna

    Energy Technology Data Exchange (ETDEWEB)

    Singleton, John; Earley, Lawrence M.; Krawczyk, Frank L.; Potter, James M.; Romero, William P.; Wang, Zhi-Fu

    2018-04-17

    A superluminal antenna element integrates a balun element to better impedance match an input cable or waveguide to a dielectric radiator element, thus preventing stray reflections and consequent undesirable radiation. For example, a dielectric housing material can be used that has a cutout area. A cable can extend into the cutout area. A triangular conductor can function as an impedance transition. An additional cylindrical element functions as a sleeve balun to better impedance match the radiator element to the cable.

  16. Hybrid method to predict the resonant frequencies and to characterise dual band proximity coupled microstrip antennas

    Science.gov (United States)

    Varma, Ruchi; Ghosh, Jayanta

    2018-06-01

    A new hybrid technique, which is a combination of neural network (NN) and support vector machine, is proposed for designing of different slotted dual band proximity coupled microstrip antennas. Slots on the patch are employed to produce the second resonance along with size reduction. The proposed hybrid model provides flexibility to design the dual band antennas in the frequency range from 1 to 6 GHz. This includes DCS (1.71-1.88 GHz), PCS (1.88-1.99 GHz), UMTS (1.92-2.17 GHz), LTE2300 (2.3-2.4 GHz), Bluetooth (2.4-2.485 GHz), WiMAX (3.3-3.7 GHz), and WLAN (5.15-5.35 GHz, 5.725-5.825 GHz) bands applications. Also, the comparative study of this proposed technique is done with the existing methods like knowledge based NN and support vector machine. The proposed method is found to be more accurate in terms of % error and root mean square % error and the results are in good accord with the measured values.

  17. Novel ring resonator-based integrated photonic beamformer for broadband phased array receive antennas - part 1: design and performance analysis

    NARCIS (Netherlands)

    Meijerink, Arjan; Roeloffzen, C.G.H.; Meijerink, Roland; Zhuang, L.; Marpaung, D.A.I.; Bentum, Marinus Jan; Burla, M.; Verpoorte, Jaco; Jorna, Pieter; Huizinga, Adriaan; van Etten, Wim

    2010-01-01

    A novel optical beamformer concept is introduced that can be used for seamless control of the reception angle in broadband wireless receivers employing a large phased array antenna (PAA). The core of this beamformer is an optical beamforming network (OBFN), using ring resonator-based broadband

  18. Single and multiple electromagnetic scattering by dielectric obstacles from a resonance perspective

    International Nuclear Information System (INIS)

    Riley, D.J.

    1987-03-01

    A new application of the singularity expansion method (SEM) is explored. This application combines the classical theory of wave propagation through a multiple-scattering environment and the SEM. Because the SEM is generally considered to be a theory for describing surface currents on conducting scatters, extensions are made which permit, under certain conditions, a singularity expansion representation for the electromagnetic field scattered by a dielectric scatterer. Application of this expansion is then made to the multiple-scattering case using both single and multiple interactions. A resonance scattering tensor form is used for the SEM description which leds to an associated tensor form for the solution to the multiple-scattering problem with each SEM pole effect appearing explicitly. The coherent field is determined for both spatial and SEM parameter random variations. A numerical example for the case of an ensemble of dielectric spheres which possess frequency-dependent loss is also made. Accurate resonance expansions for the single-scattering problem are derived, and resonance trajectories based on the Debye relaxation model for the refractive index are introduced. Application of these resonance expansions is then made to the multiple-scattering results for a slab containing a distribution of spheres with varying radii. Conditions are discussed which describe when the hybrid theory is appropriate. 53 refs., 21 figs., 9 tabs

  19. Raman scattering enhancement in photon-plasmon resonance mediated metal-dielectric microcavity

    International Nuclear Information System (INIS)

    Guddala, Sriram; Narayana Rao, D.; Dwivedi, Vindesh K.; Vijaya Prakash, G.

    2013-01-01

    Here, we report the photon-plasmon interaction scheme and enhanced field strengths resulted into the amplification of phonon in a novel microcavity. A metal-dielectric microcavity, with unified cavity photonic mode and localized surface plasmon resonances, is visualized by impregnating the gold nanoparticles into the deep see-through nano-sized pores of porous silicon microcavity. The intense optical field strengths resulting from the photon-plasmon interactions are probed by both resonant and non-resonant Raman scattering experiments. Due to photon-plasmon-phonon interaction mechanism, several orders of enhancement in the intensity of scattered Raman Stokes photon (at 500 cm −1 ) are observed. Our metal nanoparticle-microcavity hybrid system shows the potential to improve the sensing figure of merit as well as the applications of plasmonics for optoelectronics, photovoltaics, and related technologies

  20. Left-handed compact MIMO antenna array based on wire spiral resonator for 5-GHz wireless applications

    Science.gov (United States)

    Alqadami, Abdulrahman Shueai Mohsen; Jamlos, Mohd Faizal; Soh, Ping Jack; Rahim, Sharul Kamal Abdul; Narbudowicz, Adam

    2017-01-01

    A compact coplanar waveguide-fed multiple-input multiple-output antenna array based on the left-handed wire loaded spiral resonators (SR) is presented. The proposed antenna consists of a 2 × 2 wire SR with two symmetrical microstrip feed lines, each line exciting a 1 × 2 wire SR. Left-handed metamaterial unit cells are placed on its reverse side and arranged in a 2 × 3 array. A reflection coefficient of less than -16 dB and mutual coupling of less than -28 dB are achieved at 5.15 GHz WLAN band.

  1. Properties and applications of HTS-shielded dielectric resonators: A state-of-the-art report

    International Nuclear Information System (INIS)

    Klein, N.; Scholen, A.; Tellmann, N.; Zuccaro, C.; Urban, K.W.

    1996-01-01

    High temperature superconductor (HTS) shielded dielectric resonators (DRs) have demonstrated to provide quality factors Q between 5 x 10 5 and several 10 6 at frequencies up to 20 GHz and levels of dissipated rf power in the range of Watts. As dielectric materials, high purity single crystals of sapphire, LaAlO 3 , and rutile exhibit sufficiently low microwave losses. There are two main areas of application which are considered to benefit from HTS-shielded DRs, namely low-phase-noise oscillators for radar systems and digital communication, and high-power filters for satellite communication. Projections for phase noise are -145 dBc/Hz at 1 kHz offset from the carrier frequency, a value of -110 dBc/Hz at 1 kHz was measured recently for an oscillator with a carrier frequency of 5.6 GHz. Modeling of filters based on resonators with Qs in the 10 6 range indicates their ability to reduce the rf power dissipation apparent in the output multiplexers of communication satellite payloads. Presently, schemes for resonator coupling and tuning while maintaining high Qs are under development

  2. Novel dielectric photonic-band-gap resonant cavity loaded in a gyrotron

    International Nuclear Information System (INIS)

    Chen Xiaoan; Liu Gaofeng; Tang Changjian

    2010-01-01

    A novel resonant cavity composed of a periodic, multilayer, dielectric photonic crystal is proposed. Using the transfer matrix method and the Bloch theorem for periodic systems, an analysis on the band-gap property of such a structure is made, and the basic electromagnetic property of the photonic-band-gap resonant cavity (PBGC) is preliminarily exhibited. The theoretical studies and the cold cavity simulation results obtained from a high-frequency structure simulator are presented. On the basis of the present research, such a PBGC is quite similar to the two-dimensional PBGC made of triangular lattices of metal rods with a defect at its centre, in which a frequency selectivity is similarly demonstrated. Because of its unique electromagnetic property, the cavity has many promising applications in active and passive devices operating in the millimetre, sub-millimetre, and even THz wave range. As a specific application, the feasibility of substituting the traditional cylindrical resonant cavity loaded in a gyrotron for a dielectric PBGC to achieve a transverse high-order operation is discussed under the consideration of the electromagnetic features of the cavity. The study shows the great potential value of such a cavity for gyrotron devices.

  3. Acceleration of electrons at wakefield excitation by a sequence of relativistic electron bunches in dielectric resonator

    International Nuclear Information System (INIS)

    Kiselev, V.A.; Linnik, A.F.; Mirnyj, V.I.; Onishchenko, I.N.; Uskov, V.V.

    2009-01-01

    Method is proposed to divide a regular sequence of electron bunches into parts of bunches driving wakefield and witness bunches, which should be accelerated. It allows to avoid the necessity of additional electron accelerator for witness bunches producing and the necessity of precision short time techniques of injection phase adjusting. The idea concludes to the frequency detuning between bunches repetition frequency and the frequency of the fundamental mode of excited wakefield. Experiments were carried out on the linear resonant accelerator 'Almaz-2', which injected in the dielectric resonator a sequence of 6000 short bunches of relativistic electrons with energy 4.5 MeV, charge 0.16 nC and duration 60 psec each, the repetition interval 360 ps. Frequency detuning was entered by change of frequency of the master generator of the klystron within the limits of one percent so that the phase taper on the length of bunches sequence achieved 2π. Energy spectra of electrons of bunches sequence, which have been propagated through the dielectric resonator are measured and analyzed

  4. Coupled modes, frequencies and fields of a dielectric resonator and a cavity using coupled mode theory

    Science.gov (United States)

    Elnaggar, Sameh Y.; Tervo, Richard; Mattar, Saba M.

    2014-01-01

    Probes consisting of a dielectric resonator (DR) inserted in a cavity are important integral components of electron paramagnetic resonance (EPR) spectrometers because of their high signal-to-noise ratio. This article studies the behavior of this system, based on the coupling between its dielectric and cavity modes. Coupled-mode theory (CMT) is used to determine the frequencies and electromagnetic fields of this coupled system. General expressions for the frequencies and field distributions are derived for both the resulting symmetric and anti-symmetric modes. These expressions are applicable to a wide range of frequencies (from MHz to THz). The coupling of cavities and DRs of various sizes and their resonant frequencies are studied in detail. Since the DR is situated within the cavity then the coupling between them is strong. In some cases the coupling coefficient, κ, is found to be as high as 0.4 even though the frequency difference between the uncoupled modes is large. This is directly attributed to the strong overlap between the fields of the uncoupled DR and cavity modes. In most cases, this improves the signal to noise ratio of the spectrometer. When the DR and the cavity have the same frequency, the coupled electromagnetic fields are found to contain equal contributions from the fields of the two uncoupled modes. This situation is ideal for the excitation of the probe through an iris on the cavity wall. To verify and validate the results, finite element simulations are carried out. This is achieved by simulating the coupling between a cylindrical cavity's TE011 and the dielectric insert's TE01δ modes. Coupling between the modes of higher order is also investigated and discussed. Based on CMT, closed form expressions for the fields of the coupled system are proposed. These expressions are crucial in the analysis of the probe's performance.

  5. Broadband, large-area microwave antenna for optically detected magnetic resonance of nitrogen-vacancy centers in diamond

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Kento; Monnai, Yasuaki; Saijo, Soya; Fujita, Ryushiro; Ishi-Hayase, Junko; Itoh, Kohei M., E-mail: kitoh@appi.keio.ac.jp; Abe, Eisuke, E-mail: e-abe@keio.jp [School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Watanabe, Hideyuki [Correlated Electronics Group, Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1, Higashi, Tsukuba, Ibaraki 305-8565 (Japan)

    2016-05-15

    We report on a microwave planar ring antenna specifically designed for optically detected magnetic resonance (ODMR) of nitrogen-vacancy (NV) centers in diamond. It has the resonance frequency at around 2.87 GHz with the bandwidth of 400 MHz, ensuring that ODMR can be observed under external magnetic fields up to 100 G without the need of adjustment of the resonance frequency. It is also spatially uniform within the 1-mm-diameter center hole, enabling the magnetic-field imaging in the wide spatial range. These features facilitate the experiments on quantum sensing and imaging using NV centers at room temperature.

  6. Dielectric micro-resonator-based opto-mechanical systems for sensing applications

    Science.gov (United States)

    Ali, Amir Roushdy

    In recent years, whispering gallery mode (WGM), or morphology dependent optical resonances (MDR) of dielectric micro-resonators have attracted interest with proposed applications in a wide range of areas due to the high optical quality factors, Q, they can exhibit (reaching ~ 10. 9 for silica spheres). Micro-resonator WGMs have been used in applications that include those in spectroscopy, micro-cavity laser technology, optical communications (switching, filtering and multiplexing), sensors technologies and even chemical and biological sensing. The WGM of these dielectric micro-resonators are highly sensitive to morphological changes (such as the size, shape, or refractive index) of the resonance cavity and hence, can be tuned by causing a minute change in the physical condition of the surrounding. In this dissertation, we have been creating opto-mechanical systems, which at their most basic, are extraordinarily sensitive sensors. One of the ultimate goals of this dissertation is to develop sensors capable of detecting the extremely small electric field changes. To improve the performance of the sensors, we couple a polymer cantilever beam to a dielectric micro-resonator. The eventual use of such ultra sensitive electric filed sensors could include neural-machine interfaces for advanced prosthetics devices. The work presented here includes a basic analysis and experimental investigations of the electric field sensitivity and range of micro-resonators of several different materials and geometries followed by the electric field sensor design, testing, and characterization. Also, the effects of angular velocity on the WGM shifts of spherical micro-resonators are also investigated. The elastic deformation that is induced on a spinning resonator due to the centrifugal force may lead to a sufficient shift in the optical resonances and therefore interfering with its desirable operational sensor design. Furthermore, this principle could be used for the development of

  7. Resonant photon tunneling via surface plasmon polaritons through one-dimensional metal-dielectric metamaterials.

    Science.gov (United States)

    Tomita, Satoshi; Yokoyama, Takashi; Yanagi, Hisao; Wood, Ben; Pendry, John B; Fujii, Minoru; Hayashi, Shinji

    2008-06-23

    We report resonant photon tunneling (RPT) through one-dimensional metamaterials consisting of alternating layers of metal and dielectric. RPT via a surface plasmon polariton state permits evanescent light waves with large wavenumbers to be conveyed through the metamaterial. This is the mechanism for sub-wavelength imaging recently demonstrated with a super-lens. Furthermore, we find that the RPT peak is shifted from the reflectance dip with increasing the number of Al layers, indicating that the shift is caused by the losses in the RPT.

  8. Dielectric function and its predicted effect on localized plasmon resonances of equiatomic Au–Cu

    International Nuclear Information System (INIS)

    De Silva, K S B; Gentle, A; Arnold, M; Cortie, M B; Keast, V J

    2015-01-01

    Equiatomic (Au,Cu) solid solution orders below 658 K to form a tetragonal AuCu (I) phase with significant changes in physical properties and the crystal structure. The effect of ordering on the dielectric function of the material is controversial however, with inconsistent results reported in the literature. Since the nature of any localized surface plasmon resonance (LSPR) in the nanostructures is very sensitive to the dielectric function, this uncertainty hinders the use of AuCu in plasmonic devices or structures. Therefore, we re-examine the question using a combination of measurements and computations. We find that no significant change in the dielectric function occurs when this material becomes ordered, at least over the range of photon energies relevant to LSPRs. The likely properties of LSPRs in plasmonic devices made of AuCu are analyzed. Use of the alloy offers some advantages over pure Cu, however pure Au would still be the superior option in most situations. (paper)

  9. Dielectric Meta-Holograms Enabled with Dual Magnetic Resonances in Visible Light.

    Science.gov (United States)

    Li, Zile; Kim, Inki; Zhang, Lei; Mehmood, Muhammad Q; Anwar, Muhammad S; Saleem, Murtaza; Lee, Dasol; Nam, Ki Tae; Zhang, Shuang; Luk'yanchuk, Boris; Wang, Yu; Zheng, Guoxing; Rho, Junsuk; Qiu, Cheng-Wei

    2017-09-26

    Efficient transmission-type meta-holograms have been demonstrated using high-index dielectric nanostructures based on Huygens' principle. It is crucial that the geometry size of building blocks be judiciously optimized individually for spectral overlap of electric and magnetic dipoles. In contrast, reflection-type meta-holograms using the metal/insulator/metal scheme and geometric phase can be readily achieved with high efficiency and small thickness. Here, we demonstrate a general platform for design of dual magnetic resonance based meta-holograms based on the geometric phase using silicon nanostructures that are quarter wavelength thick for visible light. Significantly, the projected holographic image can be unambiguously observed without a receiving screen even under the illumination of natural light. Within the well-developed semiconductor industry, our ultrathin magnetic resonance-based meta-holograms may have promising applications in anticounterfeiting and information security.

  10. Hyperparametric effects in a whispering-gallery mode rutile dielectric resonator at liquid helium temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Nand, Nitin R.; Goryachev, Maxim; Floch, Jean-Michel le; Creedon, Daniel L.; Tobar, Michael E. [ARC Centre for Engineered Quantum Systems, School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley 6009, Western Australia (Australia)

    2014-10-07

    We report the first observation of low power drive level sensitivity, hyperparametric amplification, and single-mode hyperparametric oscillations in a dielectric rutile whispering-gallery mode resonator at 4.2 K. The latter gives rise to a comb of sidebands at 19.756 GHz. Whereas, most frequency combs in the literature have been observed in optical systems using an ensemble of equally spaced modes in microresonators or fibers, the present work represents generation of a frequency comb using only a single-mode. The experimental observations are explained by an additional 1/2 degree-of-freedom originating from an intrinsic material nonlinearity at optical frequencies, which affects the microwave properties due to the extremely low loss of rutile. Using a model based on lumped circuits, we demonstrate that the resonance between the photonic and material 1/2 degree-of-freedom, is responsible for the hyperparametric energy transfer in the system.

  11. Resonance dielectric dispersion of TEA-CoCl2Br2 nanocrystals incorporated into the PMMA matrix

    Science.gov (United States)

    Kapustianyk, V.; Shchur, Ya; Kityk, I.; Rudyk, V.; Lach, G.; Laskowski, L.; Tkaczyk, S.; Swiatek, J.; Davydov, V.

    2008-09-01

    The dielectric properties of TEA-CoCl2Br2 nanocrystals incorporated into the polymethylmethacrylate matrix within the frequency range of 3 × 105-2.6 × 109 Hz in the temperature region of 90-300 K were investigated. The considerable difference in the dielectric spectra of the nanocomposite compared to those of the bulk crystal and the pure polymer matrix was observed. The dielectric dispersion of the composite material reveals a resonance type (resonance frequency was found to be near 1.3 GHz) and may be qualitatively explained as the result of piezoelectric resonance on the nanocrystals. The model interpretation of this phenomenon based on the forced-dumped oscillator is presented.

  12. Synthesis, multi-nonlinear dielectric resonance and electromagnetic absorption properties of hcp-cobalt particles

    International Nuclear Information System (INIS)

    Wen, Shulai; Liu, Ying; Zhao, Xiuchen; Cheng, Jingwei; Li, Hong

    2014-01-01

    Hcp-cobalt particles were successfully prepared by a liquid phase reduction method, and the microstructure, static magnetic properties, electromagnetic and microwave absorption properties of the cobalt particles with irregular shape were investigated in detail. The measured results indicate that the saturation magnetization was less than that of hcp-Co single crystals, and the coercivity was larger than that of bulk cobalt crystal. The permittivity presents multi-nonlinear dielectric resonance, which may result from the irregular shape containing parts of cutting angle of dodecahedron of cobalt particles. The real part of permeability decreases with the frequency, and the imaginary part has a wide resonant peak. The paraffin-based composite containing 70 wt% cobalt particles possessed strong absorption characteristics with a minimum RL of −38.97 dB at 10.81 GHz and an absorption band with RL under −10 dB from 8.72 to 13.26 GHz when the thickness is 1.8 mm, which exhibits excellent microwave absorption in middle and high frequency. The architectural design of material morphologies is important for improving microwave absorption properties toward future application. - Highlights: • Hcp-cobalt particles were prepared by a liquid phase reduction method. • The saturation magnetization was less than that of hcp-Co single crystals. • The permittivity presents multi-nonlinear dielectric resonance. • The real part of permeability decreases with frequency, and the imaginary part presents a wide resonant peak. • The paraffin-based composite possessed a minimum RL of −38.97 dB at 10.81 GHz

  13. Implementation and Investigation of a Compact Circular Wide Slot UWB Antenna with Dual Notched Band Characteristics using Stepped Impedance Resonators

    Directory of Open Access Journals (Sweden)

    Yingsong Li

    2012-04-01

    Full Text Available A coplanar waveguide (CPW fed ultra-wideband (UWB antenna with dual notched band characteristics is presented in this paper. The circular wide slot and circular radiation patch are utilized to broaden the impedance bandwidth of the UWB antenna. The dual notched band functions are achieved by employing two stepped impedance resonators (SIRs which etched on the circular radiation patch and CPW excitation line, respectively. The two notched bands can be controlled by adjusting the dimensions of the two stepped impedance resonators which give tunable notched band functions. The proposed dual notched band UWB antenna has been designed in details and optimized by means of HFSS. Experimental and numerical results show that the proposed antenna with compact size of 32 × 24 mm2, has an impedance bandwidth range from 2.8 GHz to 13.5 Hz for voltage standing-wave ratio (VSWR less than 2, except the notch bands 5.0 GHz - 6.2 GHz for HIPERLAN/2 and IEEE 802.11a (5.1 GHz - 5.9 GHz and 8.0 GHz - 9.3 GHz for satellite and military applications.

  14. Diseño de antenas tipo DRA (Dielectric Resonator Antennas)

    OpenAIRE

    Soria Gallego, Juan

    2013-01-01

    En este trabajo se va a estudiar un tipo de antenas conocidas como antenas resonantes dieléctricas (DRA) desde el punto de vista de diseño y características radiantes, así como de sus posibles aplicaciones. Las DRAs son un tipo de antenas cada vez más usadas ya que presentan numerosas ventajas respecto a otro tipo de antenas, entre ellas que son fáciles de diseñar, baratas y muy eficientes. Por ello, cada vez aparecen nuevos diseños y nuevas aplicaciones. Entre ellas se ha extendido el uso...

  15. Micromachined On-Chip Dielectric Resonator Antenna Operating at 60 GHz

    KAUST Repository

    Sallam, Mai; Serry, Mohamed; Sedky, Sherif; Shamim, Atif; De Raedt, Walter; A.E. Vandenbosch, Guy; Soliman, Ezzeldin

    2015-01-01

    was characterized using HFSS and experimentally with good agreement been found between the simulations and experiment. The proposed DRA has good radiation characteristics, where its gain and radiation efficiency are 7 dBi and 79.35%, respectively. These properties

  16. Spectroscopic studies of resonant coupling of silver optical antenna arrays to a near-surface quantum well

    International Nuclear Information System (INIS)

    Gehl, Michael; Zandbergen, Sander; Gibson, Ricky; Nader, Nima; Sears, Jasmine; Keiffer, Patrick; Khitrova, Galina; Béchu, Muriel; Wegener, Martin; Hendrickson, Joshua

    2014-01-01

    The coupling of radiation emitted on semiconductor inter-band transitions to resonant optical-antenna arrays allows for enhanced light–matter interaction via the Purcell effect. Semiconductor optical gain also potentially allows for loss reduction in metamaterials. Here we extend our previous work on optically pumped individual near-surface InGaAs quantum wells coupled to silver split-ring-resonator arrays to wire and square-antenna arrays. By comparing the transient pump-probe experimental results with the predictions of a simple model, we find that the effective coupling is strongest for the split rings, even though the split rings have the weakest dipole moment. The effect of the latter must thus be overcompensated by a smaller effective mode volume of the split rings. Furthermore, we also present a systematic variation of the pump-pulse energy, which was fixed in our previous experiments. (paper)

  17. Spatial Steering of Cyclotron-Resonance Maser Array Antenna by Magnetic Fields

    International Nuclear Information System (INIS)

    Kesar, A.; Jerby, E.

    2001-01-01

    The novel concept of radiation lobe generation and steering by cyclotron-resonance maser (CRM) array is presented. In this scheme the gain and phase of each CRM-element in the array are tuned by magnetic fields which control the cyclotron synchronism condition and the pitch-ratio of each CRM-element. These operating parameters are controlled by the magnetic fields of the solenoid and the kicker, respectively. A numerical example of a CRM-array operating in a gyro-TWT mode is presented. The radiation pattern of a 10-element CRM phased array (15 kV, 1A each) is calculated. The radiation lobe steering by the magnetic field controls is demonstrated in this analysis. A 40 lobe steering range is shown for the 10-element CRM-array at 7.3 GHz. An experimental device is built in our laboratory to demonstrate the active CRM-array antenna concept. Preliminary experimental results of gain and phase-delay of a single CRM-element, as function of electron-beam parameters are presented. These results are compared to the numerical model

  18. 3-D Printed Fabry–Pérot Resonator Antenna with Paraboloid-Shape Superstrate for Wide Gain Bandwidth

    Directory of Open Access Journals (Sweden)

    Qiang Chen

    2017-11-01

    Full Text Available A three-dimensional (3-D printed Fabry–Pérot resonator antenna (FPRA, which designed with a paraboloid-shape superstrate for wide gain bandwidth is proposed. In comparison with the commonly-adopted planar superstrate, the paraboloid-shape superstrate is able to provide multiple resonant heights and thus satisfy the resonant condition of the FPRA in a wide frequency band. A FPRA working at 6 GHz is designed, fabricated, and tested. Considering the fabrication difficulty caused by its complex structure, the prototype antenna was fabricated by using the 3-D printing technology, i.e., all components of the prototype antenna were printed with photopolymer resin and then treated by the surface metallization process. Measurement results agree well with the simulation results, and show the 3-D printed FPRA has a |S11| < −10 dB impedance bandwidth of 12.4%, and a gain of 16.8 dBi at its working frequency of 6 GHz. Moreover, in comparison with the planar superstrate adopted in traditional FPRAs, the paraboloid-shape superstrate of the proposed FPRA significantly improves the 3-dB gain bandwidth from 6% to 22.2%.

  19. Design of S-Band Phased Array Antenna with High Isolation Using Broadside Coupled Split Ring Resonator

    Directory of Open Access Journals (Sweden)

    Sungyoun Hwang

    2018-04-01

    Full Text Available In this paper, a method of designing a Vivaldi type phased array antenna (PAA which operates at S-band (2.8–3.3 GHz is presented. The presented antenna uses broadside coupled split ring resonators (BC-SRRs for high isolation, wide field of view, and good active S-parameter characteristics. As an example, we design a 1 × 8 array antenna with various BC-SRR structures using theory and EM simulations. The antenna is fabricated and measured to verify the design. With the BC-SRR implemented between the two radiating elements, the isolation is shown to be enhanced by 6 dB, up to 23 dB. The scan angle is shown to be within ±53° based on a −10 dB active reflection coefficient. The operation of the scan angle is possible within ±60° with a little larger reflection coefficient (−7 dB to −8 dB. The proposed design with BC-SRRs is expected to be useful for PAA applications.

  20. Measurements of the anomalous RF surface resistance of niobium using a dielectric resonator

    International Nuclear Information System (INIS)

    Moffat, D.; Bolore, M.; Bonin, B.; Jacques, E.; Safa, H.

    1996-01-01

    The surface resistance of high and low RRR niobium plates at 4.2 K and 1.8 K has been measured as a function of many processing and testing parameters. A dielectric resonator was used instead of a resonant cavity. This resonator offered the ability to make many, sensitive measurements with an efficient use of time and helium. It was found that the surface resistance, R s , of RRR=190 niobium increased noticeably from the theoretical value if the cooling rate was slower than∼10 K/min. Fast-cooled plates subsequently warmed to 130 K, and the recooled, showed a larger increase in R s than plates warmed to either 100 K or 160 K. Both chemically polished, and electropolished RRR=190 plates showed the effects of the 'Q-virus'. A heat treatment of 200 deg C made the RRR=190 plates less susceptible to the 'Q-virus'. RRR=30 niobium plates did not show any increase in R s , regardless of treatment. (author)

  1. Self Oscillating Mixer with Dielectric Resonator for Low Noise Block Application

    Directory of Open Access Journals (Sweden)

    Endon Bharata

    2011-08-01

    Full Text Available In this paper, the development of a self oscillating mixer (SOM as part of a low noise block (LNB for a satellite television receiver is investigated numerically and experimentally. In contrast to other mixers, the developed SOM requires no separate local oscillator as it generates own local oscillator signal. The SOM is developed using a monolithic microwave integrated circuit (MMIC comprised of two bipolar transistors coupled as a Darlington pair and a dielectric resonator to establish a local oscillator signal. The SOM is designed to oscillate at 3.62GHz driven from 50W signal generator. The prototype of SOM is fabricated on a dielectric substrate of glass-reinforced hydrocarbon/ceramic lamination (RO4350B board which has a thickness of 0.762mm and relative permittivity of 3.66. The prototype is then characterized experimentally and exhibits a conversion gain of 8dB with the input and output voltage standing wave ratio (VSWR less than 2 across the 2520MHz to 2670MHz operating frequency band.

  2. A low-cost, Nist-traceable, high performance dielectric resonator Master Oscillator

    International Nuclear Information System (INIS)

    Doolittle, L.R.; Hovater, C.; Merminga, L.; Musson, J.; Wiseman, W.

    1999-01-01

    The current CEBAF Master Oscillator (MO) uses a quartz-based 10 MHz reference to synthesize 70 MHz and 499 MHz, which are then distributed to each of the klystron galleries on site. Due to the specialized nature of CEBAF's MO requirements, it has been determined that an in-house design and fabrication would provide a cost-effective alternative to purchasing or modifying vendor equipment. A Global Positioning System (GPS) disciplined, Direct Digital Synthesis (DDS) based MO is proposed which incorporates low-cost consumer RF components, designed for cellular communications. A 499 MHz Dielectric Resonant Oscillator (DRO) Voltage Controlled Oscillator (VCO) is phase-locked to a GPS-disciplined 10 MHz reference, and micro-tuned via a DDS, in an effort to achieve the lowest phase noise possible

  3. Analysis of SAR distribution in human head of antenna used in wireless power transform based on magnetic resonance.

    Science.gov (United States)

    Gong, Feixiang; Wei, Zhiqiang; Cong, Yanping; Chi, Haokun; Yin, Bo; Sun, Mingui

    2017-07-20

    In this paper, a novel wireless power transfer antenna system was designed for human head implantable devices. The antenna system used the structure of three plates and four coils and operated at low frequencies to transfer power via near field. In order to verify the electromagnetic radiation safety on the human head, the electromagnetic intensity and specific absorption rate (SAR) were studied by finite-difference-time-domain (FDTD) method. A three-layer model of human head including skin, bone and brain tissues was constructed. The transmitting and receiving antenna were set outside and inside the model. The local and average SAR were simulated at the resonance frequency of 18.67 MHz in two situations, in one scenario both transmitting and receiving coil worked, while in the other scenario only the transmitting coil worked. The results showed that the maximum of 10 g SAR average value of human thoracic were 0.142 W/kg and 0.148 W/kg, respectively, both were lower than the international safety standards for human body of the ICNIRP and FCC, which verified the safety of the human body in wireless power transmission based on magnetic coupling resonance.

  4. Theoretical investigation of resonance frequencies in long wavelength electromagnetic wave scattering process from plasma prolate and oblate spheroids placed in a dielectric layer

    Science.gov (United States)

    Ahmadizadeh, Y.; Jazi, B.; Abdoli-Arani, A.

    2014-01-01

    Response of a prolate spheroid plasma and/or an oblate spheroid plasma in presence of long wavelength electromagnetic wave has been studied. The resonance frequencies of these objects are obtained and it is found that they reduce to the resonance frequency of spherical cold plasma. Moreover, the resonant frequencies of prolate spheroid plasma and oblate spheroid plasma covered by a dielectric are investigated as well. Furthermore, their dependency on dielectric permittivity and geometry dimensions is simulated.

  5. An Aligned-Gap and Centered-Gap Rectangular Multiple Split Ring Resonator for Dielectric Sensing Applications

    Directory of Open Access Journals (Sweden)

    Izyani Mat Rusni

    2014-07-01

    Full Text Available This paper presents the design and development of a planar Aligned-Gap and Centered-Gap Rectangular Multiple Split Ring Resonator (SRR for microwave sensors that operates at a resonance frequency around 5 GHz. The sensor consists of a microstrip transmission line loaded with two elements of rectangular SRR on both sides. The proposed metamaterial sensors were designed and fabricated on Rogers RT5880 substrate having dielectric constant of 2.2 and thickness of 0.787 mm. The final dimension of the proposed sensor was measured at 35 × 14 mm2. Measured results show good agreement with simulated ones as well as exhibiting high Q-factor for use in sensing application. A remarkably shift of resonance frequency is observed upon introduction of several sample with different dielectric value.

  6. Effect of Two Different Superstrate Layers On Bismuth Titanate (BiT) Array Antennas

    Science.gov (United States)

    Wee, F. H.; Malek, F.; Al-Amani, A. U.; Ghani, Farid

    2014-01-01

    The microwave industry has shown increasing interest in electronic ceramic material (ECM) due to its advantages, such as light weight, low cost, low loss, and high dielectric strength. In this paper, simple antennas covered by superstrate layers for 2.30 GHz to 2.50 GHz are proposed. The antennas are compact and have the capability of producing high performance in terms of gain, directivity, and radiation efficiency. Bismuth titanate with high dielectric constant of 21, was utilized as the ECM, while the superstrate layers chosen included a split ring resonator and dielectric material. The superstrate layers were designed for some improvement in the performance of directivity, gain, and return loss. The proposed antennas were simulated and fabricated. The results obtained were small antennas that possess high gain and high directivity with 360°, omni-directional signal transmission that resonant types of conventional dipole antenna cannot achieve. The gain of the antenna with the superstrate layer was enhanced by about 1 dBi over the antenna without a superstrate layer at 2.40 GHz.

  7. RF-to-RF Characterization of a Phased Array Receive Antenna Steering System Using a Novel Ring Resonator-Based Integrated Photonic Beamformer

    NARCIS (Netherlands)

    Zhuang, L.; Burla, M.; Roeloffzen, C.G.H.; Meijerink, Arjan; Marpaung, D.A.I.; Khan, M.R.H.; van Etten, Wim; Leinse, Arne; Hoekman, M.; Heideman, Rene

    2009-01-01

    A novel ring resonator-based photonic beamformer has been developed for continuous and squint-free control of the reception angle of broadband phased array antenna systems. The core of the system is a ring resonator based optical beamforming network (OBFN) used for delay synchronization and coherent

  8. Production of atmospheric pressure microwave plasma with dielectric half-mirror resonator and its application to polymer surface treatment

    Science.gov (United States)

    Sasai, Kensuke; Keyamura, Kazuki; Suzuki, Haruka; Toyoda, Hirotaka

    2018-06-01

    For the surface treatment of a polymer tube, a ring-shaped atmospheric pressure microwave plasma (APMP) using a coaxial waveguide is studied. In this APMP, a dielectric plate is used not only as a partial mirror for cavity resonation but also for the precise alignment of the discharge gap for ring-shaped plasma production. The optimum position of the dielectric plate is investigated by electromagnetic wave simulation. On the basis of simulation results, a ring-shaped plasma with good uniformity along the ring is produced. The coaxial APMP is applied to the surface treatment of ethylene tetrafluoroethylene. A very fast surface modification within 3 s is observed.

  9. One-turn stub-loaded loop patch antenna on a small ground plane

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2005-01-01

    A small 1.1-cm3 one-turn loop patch antenna located 2.5 mm above an 18 × 25 mm ground plane separated by a dielectric substrate with relative permittivity of 9.8 is presented. By varying the length of a thin quarter-wavelength matching line, it is possible to change the resonant frequency. An RLC...

  10. Robustness of plasmonic angular momentum confinement in cross resonant optical antennas

    Energy Technology Data Exchange (ETDEWEB)

    Klaer, Peter; Lehr, Martin; Krewer, Keno; Schertz, Florian; Schönhense, Gerd; Elmers, Hans Joachim, E-mail: elmers@uni-mainz.de [Institut für Physik, Johannes Gutenberg-Universität, Staudingerweg 7, D-55099 Mainz (Germany); Razinskas, Gary; Wu, Xiao-Fei; Hecht, Bert [Institut für Physik, Julius-Maximilians-Universität, Am Hubland, 97074 Würzburg (Germany)

    2015-06-29

    Using a combination of photoemission electron microscopy and numerical simulations, we investigated the angular moment transfer in strongly enhanced optical near-fields of artificially fabricated optical antennas. The polarization dependence of the optical near-field enhancement has been measured in a maximum symmetric geometry, i.e., excitation by a normal incident planar wave. Finite-difference time-domain simulations for the realistic antenna geometries as determined by high-resolution electron microscopy reveal a very good agreement with experimental data. The agreement confirms that the geometrical asymmetries and inhomogeneities due to the nanoscale fabrication process preserve the circular polarization in the gap regions with strong near-field enhancement.

  11. Towards strong light-matter coupling at the single-resonator level with sub-wavelength mid-infrared nano-antennas

    Energy Technology Data Exchange (ETDEWEB)

    Malerba, M.; De Angelis, F., E-mail: francesco.deangelis@iit.it [Istituto Italiano di Tecnologia, Via Morego, 30, I-16163 Genova (Italy); Ongarello, T.; Paulillo, B.; Manceau, J.-M.; Beaudoin, G.; Sagnes, I.; Colombelli, R., E-mail: raffaele.colombelli@u-psud.fr [Centre for Nanoscience and Nanotechnology (C2N Orsay), CNRS UMR9001, Univ. Paris Sud, Univ. Paris Saclay, 91405 Orsay (France)

    2016-07-11

    We report a crucial step towards single-object cavity electrodynamics in the mid-infrared spectral range using resonators that borrow functionalities from antennas. Room-temperature strong light-matter coupling is demonstrated in the mid-infrared between an intersubband transition and an extremely reduced number of sub-wavelength resonators. By exploiting 3D plasmonic nano-antennas featuring an out-of-plane geometry, we observed strong light-matter coupling in a very low number of resonators: only 16, more than 100 times better than what reported to date in this spectral range. The modal volume addressed by each nano-antenna is sub-wavelength-sized and it encompasses only ≈4400 electrons.

  12. Design methodology for all-optical bistable switches based on a plasmonic resonator sandwiched between dielectric waveguides

    International Nuclear Information System (INIS)

    Xiang, Yinxiao; Cai, Wei; Wang, Lei; Ying, Cuifeng; Zhang, Xinzheng; Xu, Jingjun

    2014-01-01

    We present a bistable device consisting of a Bragg grating resonator with a Kerr medium sandwiched between two dielectric slab waveguides. The resonator is situated in a nanometer-scaled metal–insulator–metal plasmonic waveguide. Due to the dimensional confinement from the dielectric waveguide to the nanoscaled plasmonic waveguide, electric fields are enhanced greatly, which will further reduce the threshold value. Moreover, a semi-analytic method, based on the impedance theory and the transfer matrix method, is developed to study the transmission and reflection spectra as well as the bistability loop of such a switch. Our method is fast and accurate, as confirmed by the finite-difference time-domain simulation. (invited paper)

  13. Study of surface plasmon resonance of core-shell nanogeometry under the influence of perovskite dielectric environment: Electrostatic approximation

    Energy Technology Data Exchange (ETDEWEB)

    Pathak, Nilesh Kumar; Sharma, R. P. [Centre for Energy Studies, Indian Institute of Technology, Delhi-110016 (India)

    2016-05-23

    We have systematically study the nano-plasmonic coupling to the perovskite (CH{sub 3}NH{sub 3}PbI{sub 3}) dielectric media in terms of surface plasmon resonance. The surface plasmon resonances are exhibited by the metal nanoparticles which is the electromagnetic excitation conduction electron when it is irradiated by incident light photon. Tunable behaviour of SPRs can be utilized to enhance the absorption of photon inside the surrounding environment in the wavelength range 300 to 800 nm. We have been selected two different types of nanogeometry such as coated and non-coated metal nanoparticles (radii ranges from 10 to 15 nm) to understand the plasmonic interaction to the dielectric media. Finally, we have observed that the coated nanogeometry is more preferable as compared to non-coated system to analyse the tunability of SPR peaks.

  14. Enhancing the Performance of the Microwave Absorbing Materials by Using Dielectric Resonator Arrays

    Directory of Open Access Journals (Sweden)

    Omar H. Al-Zoubi

    2017-01-01

    Full Text Available We present a technique for enhancing the performance of microwave absorbing materials in terms of weight, thickness, and bandwidth. The introduced technique is based on fabricating the microwave absorbing (MA material in a structure comprised of an array of circular cylinder dielectric resonators (CDR backed by a perfect electric conductor (PEC ground plane. Numerical electromagnetic methods are employed to study the properties of the proposed MA array structures, where 3D full wave simulation using finite-element method is implemented. The obtained results show that the performance of the MA-CDR arrays significantly outperforms that of a flat layer composed of the same material and having equivalent thickness. A flat layer of MA material with thickness of 5 mm backed by perfect electric conductor (PEC shows as low as -50 dB reflection loss (RL peak and ~3 GHz 10-dB bandwidth, whereas an MA-CDR array, composed of the same MA material, of height of 4 mm can achieve as low as ~−50 dB RL peak and ~12 GHz 10-dB RL bandwidth.

  15. Simulation of a ring resonator-based optical beamformer system for phased array receive antennas

    NARCIS (Netherlands)

    Tijmes, M.R.; Meijerink, Arjan; Roeloffzen, C.G.H.; Bentum, Marinus Jan

    2009-01-01

    A new simulator tool is described that can be used in the field of RF photonics. It has been developed on the basis of a broadband, continuously tunable optical beamformer system for phased array receive antennas. The application that is considered in this paper is airborne satellite reception of

  16. Quantum-coherence-assisted tunable on- and off-resonance tunneling through a quantum-dot-molecule dielectric film

    International Nuclear Information System (INIS)

    Shen Jianqi; Zeng Ruixi

    2017-01-01

    Quantum-dot-molecular phase coherence (and the relevant quantum-interference-switchable optical response) can be utilized to control electromagnetic wave propagation via a gate voltage, since quantum-dot molecules can exhibit an effect of quantum coherence (phase coherence) when quantum-dot-molecular discrete multilevel transitions are driven by an electromagnetic wave. Interdot tunneling of carriers (electrons and holes) controlled by the gate voltage can lead to destructive quantum interference in a quantum-dot molecule that is coupled to an incident electromagnetic wave, and gives rise to a quantum coherence effect (e.g., electromagnetically induced transparency, EIT) in a quantum-dot-molecule dielectric film. The tunable on- and off-resonance tunneling effect of an incident electromagnetic wave (probe field) through such a quantum-coherent quantum-dot-molecule dielectric film is investigated. It is found that a high gate voltage can lead to the EIT phenomenon of the quantum-dot-molecular systems. Under the condition of on-resonance light tunneling through the present quantum-dot-molecule dielectric film, the probe field should propagate without loss if the probe frequency detuning is zero. Such an effect caused by both EIT and resonant tunneling, which is sensitive to the gate voltage, can be utilized for designing devices such as photonic switching, transistors, and logic gates. (author)

  17. Slots in dielectric image line as mode launchers and circuit elements

    Science.gov (United States)

    Solbach, K.

    1981-01-01

    A planar resonator model is used to investigate slots in the ground plane of dielectric image lines. An equivalent circuit representation of the slot discontinuity is obtained, and the launching efficiency of the slot as a mode launcher is analyzed. Slots are also shown to be useful in the realization of dielectric image line array antennas. It is found that the slot discontinuity can be shown as a T-junction of the dielectric image line and a metal waveguide. The launching efficiency is found to increase with the dielectric constant of the dielectric image line, exhibiting a maximum value for guides whose height is slightly less than half a wavelength in the dielectric medium. The measured launching efficiencies of low permittivity dielectric image lines are found to be in good agreement with calculated values

  18. A highly directive graphene antenna embedded inside a Fabry-Perot cavity in terahertz regime

    Science.gov (United States)

    Roshanaei, Majid; Karami, Hamidreza; Dehkhoda, Parisa; Esfahani, Hamid; Dabir, Fatemeh

    2018-05-01

    In this paper, a highly directive nano-thickness graphene-based antenna is introduced in the terahertz frequency band. The antenna is a graphene patch dipole which is placed between two Bragg mirrors called Fabry-Perot cavity. Tunability of the graphene's conductivity makes it possible to excite the desired resonances of the cavity. Here, first, a single resonant antenna is introduced at 5 THz with an enhanced gain from 2.11 dBi to 12.8 dBi with a beamwidth of 22.7°. Then, a triple resonant antenna at 4.7, 5 and 5.3 THz is presented with respective gains of 7.97, 11.9 and 8.52 dBi. Finally, the effect of dimensions and number of the dielectric layers of the cavity are studied in order to further increase in directivity.

  19. High-efficiency water-loaded microwave antenna in ultra-high-frequency band

    Science.gov (United States)

    Gong, Zilun; Bartone, Chris; Yang, Fuyi; Yao, Jie

    2018-03-01

    High-index dielectrics are widely used in microwave antennas to control the radiation characteristics. Liquid water, with a high dielectric index at microwave frequency, is an interesting material to achieving tunable functionalities. Here, we demonstrate a water-loaded microwave antenna system that has high loss-tolerance and wideband tunability enabled by fluidity. Our simulation and experimental results show that the resonance frequency can be effectively tuned by the size of loading water. Furthermore, the antenna systems with water loading can achieve high radiation efficiency (>90%) in the ultra-high-frequency (0.3-3 GHz) band. This work brings about opportunities in realistic tunable microwave antenna designs enabled by liquid.

  20. A novel method of support vector machine to compute the resonant frequency of annular ring compact microstrip antennas

    Directory of Open Access Journals (Sweden)

    Ahmet Kayabasi

    2015-12-01

    Full Text Available An application of support vector machine (SVM to compute the resonant frequency at dominant mode TM11 of annular ring compact microstrip antennas (ARCMAs is presented in this paper. ARCMAs have some useful features; resonant modes can be adjusted by controlling the ratio of the outer radius to the inner radius. The resonant frequencies of 100 ARCMAs with varied dimensions and electrical parameters in accordance with UHF band covering GSM, LTE, WLAN, and WiMAX applications were simulated with IE3D™ which is a robust numerical electromagnetic computational tool. Then, the SVM model was built with simulation data and 88 simulated ARCMAs were operated for training and the remaining 12 ARCMAs were used for testing this model. The proposed model has been confirmed by comparing with the suggestions reported elsewhere via measurement data published earlier in the literature, and it has further validated on an ARCMA operating at 3 GHz fabricated in this study. The obtained results show that this technique can be successfully used to compute the resonant frequency of ARCMAs without involving any sophisticated methods. The novelty of the approach described here is to offer ease of designing the process using this method.

  1. Modeling of compact loop antennas

    International Nuclear Information System (INIS)

    Baity, F.W.

    1987-01-01

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively-tuned resonant double loop (RDL) antennas the model treats stub-tuned resonant double loop antennas. Calculations using the model have been compared with measurements on full-scale mockups of resonant double loop antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and for the Compact Ignition Tokamak

  2. Ferromagnetic resonance in a single crystal of iron borate and magnetic field tuning of hybrid oscillations in a composite structure with a dielectric: Experiment and theory

    International Nuclear Information System (INIS)

    Popov, M. A.; Zavislyak, I. V.; Chumak, H. L.; Strugatsky, M. B.; Yagupov, S. V.; Srinivasan, G.

    2015-01-01

    The high-frequency properties of a composite resonator comprised single crystal iron borate (FeBO 3 ), a canted antiferromagnet with a weak ferromagnetic moment, and a polycrystalline dielectric were investigated at 9–10 GHz. Ferromagnetic resonance in this frequency range was observed in FeBO 3 for bias magnetic fields of ∼250 Oe. In the composite resonator, the magnetic mode in iron borate and dielectric mode are found to hybridize strongly. It is shown that the hybrid mode can be tuned with a static magnetic field. Our studies indicate that coupling between the magnetic mode and the dielectric resonance can be altered from maximum hybridization to a minimum by adjusting the position of resonator inside the waveguide. Magnetic field tuning of the resonance frequency by a maximum of 145 MHz and a change in the transmitted microwave power by as much as 16 dB have been observed for a bias field of 250 Oe. A model is discussed for the magnetic field tuning of the composite resonator and theoretical estimates are in reasonable agreement with the data. The composite resonator with a weak ferromagnet and a dielectric is of interest for application in frequency agile devices with electronically tunable electrodynamic characteristics for the mm and sub-mm wave bands

  3. Mid-infrared plasmonic resonances exploiting heavily-doped Ge on Si

    Science.gov (United States)

    Biagioni, P.; Sakat, E.; Baldassarre, L.; Calandrini, E.; Samarelli, A.; Gallacher, K.; Frigerio, J.; Isella, G.; Paul, D. J.; Ortolani, M.

    2015-03-01

    We address the behavior of mid-infrared localized plasmon resonances in elongated germanium antennas integrated on silicon substrates. Calculations based on Mie theory and on the experimentally retrieved dielectric constant allow us to study the tunability and the figures of merit of plasmon resonances in heavily-doped germanium and to preliminarily compare them with those of the most established plasmonic material, gold.

  4. Post-fabrication voltage controlled resonance tuning of nanoscale plasmonic antennas.

    Science.gov (United States)

    Lumdee, Chatdanai; Toroghi, Seyfollah; Kik, Pieter G

    2012-07-24

    Voltage controlled wavelength tuning of the localized surface plasmon resonance of gold nanoparticles on an aluminum film is demonstrated in single particle microscopy and spectroscopy measurements. Anodization of the Al film after nanoparticle deposition forms an aluminum oxide spacer layer between the gold particles and the Al film, modifying the particle-substrate interaction. Darkfield microscopy reveals ring-shaped scattering images from individual Au nanoparticles, indicative of plasmon resonances with a dipole moment normal to the substrate. Single particle scattering spectra show narrow plasmon resonances that can be tuned from ~580 to ~550 nm as the anodization voltage increases to 12 V. All observed experimental trends could be reproduced in numerical simulations. The presented approach could be used as a general postfabrication resonance optimization step of plasmonic nanoantennas and devices.

  5. Theoretical Study of Local Surface Plasmon Resonances on a Dielectric-Ag Core-Shell Nanosphere Using the Discrete-Dipole Approximation Method

    International Nuclear Information System (INIS)

    Ma Ye-Wan; Wu Zhao-Wang; Zhang Li-Hua; Liu Wan-Fang; Zhang Jie

    2015-01-01

    The local surface plasmon resonances (LSPRs) of dielectric-Ag core-shell nanospheres are studied by the discretedipole approximation method. The result shows that LSPRs are sensitive to the surrounding medium refractive index, which shows a clear red-shift with the increasing surrounding medium refractive index. A dielectric-Ag core-shell nanosphere exhibits a strong coupling between the core and shell plasmon resonance modes. LSPRs depend on the shell thickness and the composition of dielectric-core and metal-shell. LSPRs can be tuned over a longer wavelength range by changing the ratio of core to shell value. The lower energy mode ω_− shows a red-shift with the increasing dielectric-core value and the inner core radius, while blue-shifted with the increasing outer shell thickness. The underlying mechanisms are analyzed with the plasmon hybridization theory and the phase retardation effect. (paper)

  6. Compact circularly polarized truncated square ring slot antenna with suppressed higher resonances.

    Directory of Open Access Journals (Sweden)

    Mursyidul Idzam Sabran

    Full Text Available This paper presents a compact circularly polarized (CP antenna with an integrated higher order harmonic rejection filter. The proposed design operates within the ISM band of 2.32 GHz- 2.63 GHz and is suitable for example for wireless power transfer applications. Asymmetrical truncated edges on a square ring create a defected ground structure to excite the CP property, simultaneously realizing compactness. It offers a 50.5% reduced patch area compared to a conventional design. Novel stubs and slot shapes are integrated in the transmission line to reduce higher (up to the third order harmonics. The proposed prototype yields a -10 dB reflection coefficient (S11 impedance bandwidth of 12.53%, a 3 dB axial ratio bandwidth of 3.27%, and a gain of 5.64 dBi. Measurements also show good agreement with simulations.

  7. The Ultrawideband Leaky Lens Antenna

    NARCIS (Netherlands)

    Bruni, S.; Neto, A.; Marliani, F.

    2007-01-01

    A novel directive and nondispersive antenna is presented: the ultrawideband (UWB) leaky lens. It is based on the broad band Cherenkov radiation occurring at a slot printed between different infinite homogeneous dielectrics. The first part of the paper presents the antenna concept and the UWB design.

  8. Calculation of heat fluxes induced by radio frequency heating on the actively cooled protections of ion cyclotron resonant heating (ICRH) and lower hybrid (LH) antennas in Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Ritz, G., E-mail: Guillaume.ritz@gmail.com [CEA, Institut de la Recherche sur la Fusion Magnétique (IRFM), 13108 Saint Paul-lez-Durance (France); Corre, Y., E-mail: Yann.corre@cea.fr [CEA, Institut de la Recherche sur la Fusion Magnétique (IRFM), 13108 Saint Paul-lez-Durance (France); Rault, M.; Missirlian, M. [CEA, Institut de la Recherche sur la Fusion Magnétique (IRFM), 13108 Saint Paul-lez-Durance (France); Portafaix, C. [ITER Organization, Route de Vinon-sur-Verdon, 13115 Saint Paul-lez-Durance (France); Martinez, A.; Ekedahl, A.; Colas, L.; Guilhem, D.; Salami, M.; Loarer, T. [CEA, Institut de la Recherche sur la Fusion Magnétique (IRFM), 13108 Saint Paul-lez-Durance (France)

    2013-10-15

    Highlights: ► The heat flux generated by radiofrequency (RF) heating was calculated using Tore Supra's heating antennas. ► The highest heat flux value, generated by ions accelerated in RF-rectified sheath potentials, was 5 MW/m{sup 2}. ► The heat flux on the limiters of antennas was in the same order of magnitude as that on the toroidal pumping limiter. -- Abstract: Lower hybrid current drive (LHCD) and ion cyclotron resonance heating (ICRH) are recognized as important auxiliary heating and current drive methods for present and next step fusion devices. However, these radio frequency (RF) systems generate a heat flux up to several MW/m{sup 2} on the RF antennas during plasma operation. This paper focuses on the determination of the heat flux deposited on the lateral protections of the RF antennas in Tore Supra. The heat flux was calculated by finite element method (FEM) using a model of the lateral protection. The FEM calculation was based on surface temperature measurements using infrared cameras monitoring the RF antennas. The heat flux related to the acceleration of electrons in front of the LHCD grills (LHCD active) and to the acceleration of ions in RF-rectified sheath potentials (ICRH active) were calculated. Complementary results on the heat flux related to fast ions (ICRH active with a relatively low magnetic field) are also reported in this paper.

  9. Circularly polarized antennas for active holographic imaging through barriers

    Science.gov (United States)

    McMakin, Douglas L [Richland, WA; Severtsen, Ronald H [Richland, WA; Lechelt, Wayne M [West Richland, WA; Prince, James M [Kennewick, WA

    2011-07-26

    Circularly-polarized antennas and their methods of use for active holographic imaging through barriers. The antennas are dielectrically loaded to optimally match the dielectric constant of the barrier through which images are to be produced. The dielectric loading helps to remove barrier-front surface reflections and to couple electromagnetic energy into the barrier.

  10. Resonant laser printing of structural colors on high-index dielectric metasurfaces

    DEFF Research Database (Denmark)

    Zhu, Xiaolong; Yan, Wei; Levy, Uriel

    2017-01-01

    -dependent resonances. Strong on-resonance energy absorption under pulsed laser irradiation locally elevates the lattice temperature (exceeding 1200 K) in an ultrashort time scale (1 ns). This forms the basis for resonant laser printing, where rapid melting allows for surface energy-driven morphology changes...

  11. Investigation of a nanostrip patch antenna in optical frequencies

    Science.gov (United States)

    Kashyap, Nitesh; Wani, Zamir Ahmad; Jain, Rishi; Khusboo; Dinesh Kumar, V.

    2014-08-01

    This is the first report and investigation of a patch antenna in optical frequency range. Variety of plasmonic nanoantenna reported so far is good at enhancing the local field intensity of light by orders of magnitude. However, their far-field radiation efficiency is very poor. The proposed patch antenna emits a directional beam with high efficacy in addition to enhancing the intensity of near field. The nano-patch antenna (NPA) consists of a square patch of gold film of dimension 480 nm2, placed on a substrate of dielectric constant \\varepsilon_{{r}} = 3.9 and thickness 150 nm with a ground plane of gold film of dimension 1,080 nm2. The NPA resonates at 210 THz and has gain nearly 2 dB and radiation efficiency 45.18 %. The NPA might be useful in variety of applications such as optical communication, nano-photonics, biosensing, and spectroscopy.

  12. Slot Antenna Integrated Re-Entrant Resonator Based Wireless Pressure Sensor for High-Temperature Applications.

    Science.gov (United States)

    Su, Shujing; Lu, Fei; Wu, Guozhu; Wu, Dezhi; Tan, Qiulin; Dong, Helei; Xiong, Jijun

    2017-08-25

    The highly sensitive pressure sensor presented in this paper aims at wireless passive sensing in a high temperature environment by using microwave backscattering technology. The structure of the re-entrant resonator was analyzed and optimized using theoretical calculation, software simulation, and its equivalent lump circuit model was first modified by us. Micro-machining and high-temperature co-fired ceramic (HTCC) process technologies were applied to fabricate the sensor, solving the common problem of cavity sealing during the air pressure loading test. In addition, to prevent the response signal from being immersed in the strong background clutter of the hermetic metal chamber, which makes its detection difficult, we proposed two key techniques to improve the signal to noise ratio: the suppression of strong background clutter and the detection of the weak backscattered signal of the sensor. The pressure sensor demonstrated in this paper works well for gas pressure loading between 40 and 120 kPa in a temperature range of 24 °C to 800 °C. The experimental results show that the sensor resonant frequency lies at 2.1065 GHz, with a maximum pressure sensitivity of 73.125 kHz/kPa.

  13. Phenomena of nonlinear oscillation and special resonance of a dielectric elastomer minimum energy structure rotary joint

    Science.gov (United States)

    Zhao, Jianwen; Niu, Junyang; McCoul, David; Ren, Zhi; Pei, Qibing

    2015-03-01

    The dielectric elastomer minimum energy structure can realize large angular deformations by a small voltage-induced strain of the dielectric elastomer, so it is a suitable candidate to make a rotary joint for a soft robot. Driven with an alternating electric field, the joint deformation vibrational frequency follows the input voltage frequency. However, the authors find that if the rotational inertia increases such that the inertial torque makes the frame deform over a negative angle, then the joint motion will become complicated and the vibrational mode will alter with the change of voltage frequency. The vibration with the largest amplitude does not occur while the voltage frequency is equal to natural response frequency of the joint. Rather, the vibrational amplitude will be quite large over a range of other frequencies at which the vibrational frequency is half of the voltage frequency. This phenomenon was analyzed by a comparison of the timing sequences between voltage and joint vibration. This vibrational mode with the largest amplitude can be applied to the generation lift in a flapping wing actuated by dielectric elastomers.

  14. Demonstration of Magnetic Dipole Resonances of Dielectric Nanospheres in the Visible Region

    DEFF Research Database (Denmark)

    Evlyukhin, A. B.; Novikov, S. M.; Zywietz, U.

    2012-01-01

    Strong resonant light scattering by individual spherical Si nanoparticles is experimentally demonstrated, revealing pronounced resonances associated with the excitation of magnetic and electric modes in these nanoparticles. It is shown that the low-frequency resonance corresponds to the magnetic...... dipole excitation. Due to high permittivity, the magnetic dipole resonance is observed in the visible spectral range for Si nanoparticles with diameters of similar to 200 nm, thereby opening a way to the realization of isotropic optical metamaterials with strong magnetic responses in the visible region....

  15. Magneto-Plasmonics and Resonant Interaction of Light with Dynamic Magnetisation in Metallic and All-Magneto-Dielectric Nanostructures.

    Science.gov (United States)

    Maksymov, Ivan S

    2015-04-09

    A significant interest in combining plasmonics and magnetism at the nanoscale gains momentum in both photonics and magnetism sectors that are concerned with the resonant enhancement of light-magnetic-matter interaction in nanostructures. These efforts result in a considerable amount of literature, which is difficult to collect and digest in limited time. Furthermore, there is insufficient exchange of results between the two research sectors. Consequently, the goal of this review paper is to bridge this gap by presenting an overview of recent progress in the field of magneto-plasmonics from two different points of view: magneto-plasmonics, and magnonics and magnetisation dynamics. It is expected that this presentation style will make this review paper of particular interest to both general physical audience and specialists conducting research on photonics, plasmonics, Brillouin light scattering spectroscopy of magnetic nanostructures and magneto-optical Kerr effect magnetometry, as well as ultrafast all-optical and THz-wave excitation of spin waves. Moreover, readers interested in a new, rapidly emerging field of all-dielectric nanophotonics will find a section about all-magneto-dielectric nanostructures.

  16. Magneto-Plasmonics and Resonant Interaction of Light with Dynamic Magnetisation in Metallic and All-Magneto-Dielectric Nanostructures

    Directory of Open Access Journals (Sweden)

    Ivan S. Maksymov

    2015-04-01

    Full Text Available A significant interest in combining plasmonics and magnetism at the nanoscale gains momentum in both photonics and magnetism sectors that are concerned with the resonant enhancement of light-magnetic-matter interaction in nanostructures. These efforts result in a considerable amount of literature, which is difficult to collect and digest in limited time. Furthermore, there is insufficient exchange of results between the two research sectors. Consequently, the goal of this review paper is to bridge this gap by presenting an overview of recent progress in the field of magneto-plasmonics from two different points of view: magneto-plasmonics, and magnonics and magnetisation dynamics. It is expected that this presentation style will make this review paper of particular interest to both general physical audience and specialists conducting research on photonics, plasmonics, Brillouin light scattering spectroscopy of magnetic nanostructures and magneto-optical Kerr effect magnetometry, as well as ultrafast all-optical and THz-wave excitation of spin waves. Moreover, readers interested in a new, rapidly emerging field of all-dielectric nanophotonics will find a section about all-magneto-dielectric nanostructures.

  17. Application of Atomic Dielectric Resonance Spectroscopy for the screening of blood samples from patients with clinical variant and sporadic CJD

    Directory of Open Access Journals (Sweden)

    Ironside James W

    2007-08-01

    Full Text Available Abstract Background Sub-clinical variant Creutzfeldt-Jakob disease (vCJD infection and reports of vCJD transmission through blood transfusion emphasise the need for blood screening assays to ensure the safety of blood and transplanted tissues. Most assays aim to detect abnormal prion protein (PrPSc, although achieving required sensitivity is a challenge. Methods We have used innovative Atomic Dielectric Resonance Spectroscopy (ADRS, which determines dielectric properties of materials which are established by reflectivity and penetration of radio/micro waves, to analyse blood samples from patients and controls to identify characteristic ADR signatures unique to blood from vCJD and to sCJD patients. Initial sets of blood samples from vCJD, sCJD, non-CJD neurological diseases and normal healthy adults (blood donors were screened as training samples to determine group-specific ADR characteristics, and provided a basis for classification of blinded sets of samples. Results Blood sample groups from vCJD, sCJD, non-CJD neurological diseases and normal healthy adults (blood donors screened by ADRS were classified with 100% specificity and sensitivity, discriminating these by a co-variance expert analysis system. Conclusion ADRS appears capable of recognising and discriminating serum samples from vCJD, sCJD, non-CJD neurological diseases, and normal healthy adults, and might be developed to provide a system for primary screening or confirmatory assay complementary to other screening systems.

  18. Application of Atomic Dielectric Resonance Spectroscopy for the screening of blood samples from patients with clinical variant and sporadic CJD

    Science.gov (United States)

    Fagge, Timothy J; Barclay, G Robin; Stove, G Colin; Stove, Gordon; Robinson, Michael J; Head, Mark W; Ironside, James W; Turner, Marc L

    2007-01-01

    Background Sub-clinical variant Creutzfeldt-Jakob disease (vCJD) infection and reports of vCJD transmission through blood transfusion emphasise the need for blood screening assays to ensure the safety of blood and transplanted tissues. Most assays aim to detect abnormal prion protein (PrPSc), although achieving required sensitivity is a challenge. Methods We have used innovative Atomic Dielectric Resonance Spectroscopy (ADRS), which determines dielectric properties of materials which are established by reflectivity and penetration of radio/micro waves, to analyse blood samples from patients and controls to identify characteristic ADR signatures unique to blood from vCJD and to sCJD patients. Initial sets of blood samples from vCJD, sCJD, non-CJD neurological diseases and normal healthy adults (blood donors) were screened as training samples to determine group-specific ADR characteristics, and provided a basis for classification of blinded sets of samples. Results Blood sample groups from vCJD, sCJD, non-CJD neurological diseases and normal healthy adults (blood donors) screened by ADRS were classified with 100% specificity and sensitivity, discriminating these by a co-variance expert analysis system. Conclusion ADRS appears capable of recognising and discriminating serum samples from vCJD, sCJD, non-CJD neurological diseases, and normal healthy adults, and might be developed to provide a system for primary screening or confirmatory assay complementary to other screening systems. PMID:17760958

  19. Influence of the electron cyclotron resonance plasma confinement on reducing the bremsstrahlung production of an electron cyclotron resonance ion source with metal-dielectric structures.

    Science.gov (United States)

    Schachter, L; Stiebing, K E; Dobrescu, S

    2009-01-01

    The influence of metal-dielectric (MD) layers (MD structures) inserted into the plasma chamber of an electron cyclotron resonance ion source (ECRIS) onto the production of electron bremsstrahlung radiation has been studied in a series of dedicated experiments at the 14 GHz ECRIS of the Institut für Kernphysik der Universität Frankfurt. The IKF-ECRIS was equipped with a MD liner, covering the inner walls of the plasma chamber, and a MD electrode, covering the plasma-facing side of the extraction electrode. On the basis of similar extracted currents of highly charged ions, significantly reduced yields of bremsstrahlung radiation for the "MD source" as compared to the standard (stainless steel) source have been measured and can be explained by the significantly better plasma confinement in a MD source as compared to an "all stainless steel" ECRIS.

  20. Influence of the electron cyclotron resonance plasma confinement on reducing the bremsstrahlung production of an electron cyclotron resonance ion source with metal-dielectric structures

    International Nuclear Information System (INIS)

    Schachter, L.; Dobrescu, S.; Stiebing, K. E.

    2009-01-01

    The influence of metal-dielectric (MD) layers (MD structures) inserted into the plasma chamber of an electron cyclotron resonance ion source (ECRIS) onto the production of electron bremsstrahlung radiation has been studied in a series of dedicated experiments at the 14 GHz ECRIS of the Institut fuer Kernphysik der Universitaet Frankfurt. The IKF-ECRIS was equipped with a MD liner, covering the inner walls of the plasma chamber, and a MD electrode, covering the plasma-facing side of the extraction electrode. On the basis of similar extracted currents of highly charged ions, significantly reduced yields of bremsstrahlung radiation for the 'MD source' as compared to the standard (stainless steel) source have been measured and can be explained by the significantly better plasma confinement in a MD source as compared to an ''all stainless steel'' ECRIS.

  1. Ion cyclotron resonance heating (ICRH) start-up antenna for the mirror fusion test facility (MFTF-B)

    International Nuclear Information System (INIS)

    McCarville, T.M.; Romesser, T.E.

    1985-01-01

    The purpose of the ICRH start-up antenna on MFTF-B is to heat the plasma and control the ion distribution as the density increases during start-up. The antenna, consisting of two center fed half turn loops phased 180 0 apart, has been designed for 1 MW of input power, with a goal of coupling 400 kW into the ions. To vary the heating frequency relative to the local ion cyclotron frequency, the antenna is tunable over a range from 7.5 to 12.5 MHz. The thermal requirements common to low duty cycle ICRH antennas are especially severe for the MFTF-B antenna. The stress requirements are also unique, deriving from the possibility of seismic activity or JxB forces if the magnets unexpectedly quench. Considerable attention has been paid to contact control at high current bolt-up joints, and arranging geometries so as to minimize the possibility of voltage breakdown

  2. Resonant nano-antennas for light trapping in plasmonic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mokkapati, S; Beck, F J; Catchpole, K R [Centre for Sustainable Energy Systems, College of Engineering and Computer Science, Australian National University, Canberra, 0200 (Australia); De Waele, R; Polman, A, E-mail: sudha.mokkapati@anu.edu.au [Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam (Netherlands)

    2011-05-11

    We investigate the influence of nanoparticle height on light trapping in thin-film solar cells covered with metal nanoparticles. We show that in taller nanoparticles the scattering cross-section is enhanced by resonant excitation of plasmonic standing waves. Tall nanoparticles have higher coupling efficiency when placed on the illuminated surface of the cell than on the rear of the cell due to their forward scattering nature. One of the major factors affecting the coupling efficiency of these particles is the phase shift of surface plasmon polaritons propagating along the nanoparticle due to reflection from the Ag/Si or Ag/air interface. The high scattering cross-sections of tall nanoparticles on the illuminated surface of the cell could be exploited for efficient light trapping by modifying the coupling efficiency of nanoparticles by engineering this phase shift. We demonstrate that the path length enhancement (with a nanoparticle of height 500 nm) at an incident wavelength of 700 nm can be increased from {approx}6 to {approx}16 by modifying the phase shift at the Ag/air interface by coating the surface of the nanoparticle with a layer of Si.

  3. Design of Meter-Scale Antenna and Signal Detection System for Underground Magnetic Resonance Sounding in Mines.

    Science.gov (United States)

    Yi, Xiaofeng; Zhang, Jian; Fan, Tiehu; Tian, Baofeng; Jiang, Chuandong

    2018-03-13

    Magnetic resonance sounding (MRS) is a novel geophysical method to detect groundwater directly. By applying this method to underground projects in mines and tunnels, warning information can be provided on water bodies that are hidden in front prior to excavation and thus reduce the risk of casualties and accidents. However, unlike its application to ground surfaces, the application of MRS to underground environments is constrained by the narrow space, quite weak MRS signal, and complex electromagnetic interferences with high intensities in mines. Focusing on the special requirements of underground MRS (UMRS) detection, this study proposes the use of an antenna with different turn numbers, which employs a separated transmitter and receiver. We designed a stationary coil with stable performance parameters and with a side length of 2 m, a matching circuit based on a Q-switch and a multi-stage broad/narrowband mixed filter that can cancel out most electromagnetic noise. In addition, noises in the pass-band are further eliminated by adopting statistical criteria and harmonic modeling and stacking, all of which together allow weak UMRS signals to be reliably detected. Finally, we conducted a field case study of the UMRS measurement in the Wujiagou Mine in Shanxi Province, China, with known water bodies. Our results show that the method proposed in this study can be used to obtain UMRS signals in narrow mine environments, and the inverted hydrological information generally agrees with the actual situation. Thus, we conclude that the UMRS method proposed in this study can be used for predicting hazardous water bodies at a distance of 7-9 m in front of the wall for underground mining projects.

  4. Design of Meter-Scale Antenna and Signal Detection System for Underground Magnetic Resonance Sounding in Mines

    Directory of Open Access Journals (Sweden)

    Xiaofeng Yi

    2018-03-01

    Full Text Available Magnetic resonance sounding (MRS is a novel geophysical method to detect groundwater directly. By applying this method to underground projects in mines and tunnels, warning information can be provided on water bodies that are hidden in front prior to excavation and thus reduce the risk of casualties and accidents. However, unlike its application to ground surfaces, the application of MRS to underground environments is constrained by the narrow space, quite weak MRS signal, and complex electromagnetic interferences with high intensities in mines. Focusing on the special requirements of underground MRS (UMRS detection, this study proposes the use of an antenna with different turn numbers, which employs a separated transmitter and receiver. We designed a stationary coil with stable performance parameters and with a side length of 2 m, a matching circuit based on a Q-switch and a multi-stage broad/narrowband mixed filter that can cancel out most electromagnetic noise. In addition, noises in the pass-band are further eliminated by adopting statistical criteria and harmonic modeling and stacking, all of which together allow weak UMRS signals to be reliably detected. Finally, we conducted a field case study of the UMRS measurement in the Wujiagou Mine in Shanxi Province, China, with known water bodies. Our results show that the method proposed in this study can be used to obtain UMRS signals in narrow mine environments, and the inverted hydrological information generally agrees with the actual situation. Thus, we conclude that the UMRS method proposed in this study can be used for predicting hazardous water bodies at a distance of 7–9 m in front of the wall for underground mining projects.

  5. Resonant cavity light-emitting diodes based on dielectric passive cavity structures

    Science.gov (United States)

    Ledentsov, N.; Shchukin, V. A.; Kropp, J.-R.; Zschiedrich, L.; Schmidt, F.; Ledentsov, N. N.

    2017-02-01

    A novel design for high brightness planar technology light-emitting diodes (LEDs) and LED on-wafer arrays on absorbing substrates is proposed. The design integrates features of passive dielectric cavity deposited on top of an oxide- semiconductor distributed Bragg reflector (DBR), the p-n junction with a light emitting region is introduced into the top semiconductor λ/4 DBR period. A multilayer dielectric structure containing a cavity layer and dielectric DBRs is further processed by etching into a micrometer-scale pattern. An oxide-confined aperture is further amended for current and light confinement. We study the impact of the placement of the active region into the maximum or minimum of the optical field intensity and study an impact of the active region positioning on light extraction efficiency. We also study an etching profile composed of symmetric rings in the etched passive cavity over the light emitting area. The bottom semiconductor is an AlGaAs-AlAs multilayer DBR selectively oxidized with the conversion of the AlAs layers into AlOx to increase the stopband width preventing the light from entering the semiconductor substrate. The approach allows to achieve very high light extraction efficiency in a narrow vertical angle keeping the reasonable thermal and current conductivity properties. As an example, a micro-LED structure has been modeled with AlGaAs-AlAs or AlGaAs-AlOx DBRs and an active region based on InGaAlP quantum well(s) emitting in the orange spectral range at 610 nm. A passive dielectric SiO2 cavity is confined by dielectric Ta2O5/SiO2 and AlGaAs-AlOx DBRs. Cylindrically-symmetric structures with multiple ring patterns are modeled. It is demonstrated that the extraction coefficient of light to the air can be increased from 1.3% up to above 90% in a narrow vertical angle (full width at half maximum (FWHM) below 20°). For very small oxide-confined apertures 100nm the narrowing of the FWHM for light extraction can be reduced down to 5

  6. Dielectric platforms for surface-enhanced spectroscopies (Conference Presentation)

    Science.gov (United States)

    Maier, Stefan A.

    2016-03-01

    Plasmonic nanostructures serve as the main backbone of surface enhanced sensing methodologies, yet the associated optical losses lead to localized heating as well as quenching of molecules, complicating their use for enhancement of fluorescent emission. Additionally, conventional plasmonic materials are limited to operation in the visible part of the spectrum. We will elucidate how nanostructures consisting of conventional and polar dielectrics can be employed as a highly promising alternative platform. Dielectric nanostructures can sustain scattering resonances due to both electric and magnetic Mie modes. We have recently predicted high enhanced local electromagnetic field hot spots in dielectric nanoantenna dimers, with the hallmark of spot sizes comparable to those achievable with plasmonic antennas, but with lower optical losses. Here, we will present first experimental evidence for both fluorescence and Raman enhancement in dielectric nanoantennas, including a direct determination of localized heating, and compare to conventional Au dimer antennas. The second part of the talk will focus on the mid-infrared regime of the electromagnetic spectrum, outlining possibilities for surface enhanced infrared absorption spectroscopy based on polar and hyperbolic dielectrics.

  7. CH3 NH3 PbBr3 Perovskite Nanocrystals as Efficient Light-Harvesting Antenna for Fluorescence Resonance Energy Transfer.

    Science.gov (United States)

    Muthu, Chinnadurai; Vijayan, Anuja; Nair, Vijayakumar C

    2017-05-04

    Hybrid perovskites have created enormous research interest as a low-cost material for high-performance photovoltaic devices, light-emitting diodes, photodetectors, memory devices and sensors. Perovskite materials in nanocrystal form that display intense luminescence due to the quantum confinement effect were found to be particularly suitable for most of these applications. However, the potential use of perovskite nanocrystals as a light-harvesting antenna for possible applications in artificial photosynthesis systems is not yet explored. In the present work, we study the light-harvesting antenna properties of luminescent methylammonium lead bromide (CH 3 NH 3 PbBr 3 )-based perovskite nanocrystals using fluorescent dyes (rhodamine B, rhodamine 101, and nile red) as energy acceptors. Our studies revealed that CH 3 NH 3 PbBr 3 nanocrystals are an excellent light-harvesting antenna, and efficient fluorescence resonance energy transfer occurs from the nanocrystals to fluorescent dyes. Further, the energy transfer efficiency is found to be highly dependent on the number of anchoring groups and binding ability of the dyes to the surface of the nanocrystals. These observations may have significant implications for perovskite-based light-harvesting devices and their possible use in artificial photosynthesis systems. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Tailoring the chirality of light emission with spherical Si-based antennas.

    Science.gov (United States)

    Zambrana-Puyalto, Xavier; Bonod, Nicolas

    2016-05-21

    Chirality of light is of fundamental importance in several enabling technologies with growing applications in life sciences, chemistry and photodetection. Recently, some attention has been focused on chiral quantum emitters. Consequently, optical antennas which are able to tailor the chirality of light emission are needed. Spherical nanoresonators such as colloids are of particular interest to design optical antennas since they can be synthesized at a large scale and they exhibit good optical properties. Here, we show that these colloids can be used to tailor the chirality of a chiral emitter. To this purpose, we derive an analytic formalism to model the interaction between a chiral emitter and a spherical resonator. We then compare the performances of metallic and dielectric spherical antennas to tailor the chirality of light emission. It is seen that, due to their strong electric dipolar response, metallic spherical nanoparticles spoil the chirality of light emission by yielding achiral fields. In contrast, thanks to the combined excitation of electric and magnetic modes, dielectric Si-based particles feature the ability to inhibit or to boost the chirality of light emission. Finally, it is shown that dual modes in dielectric antennas preserve the chirality of light emission.

  9. Swept frequency measurements of microwave antennas in feline and canine brain

    International Nuclear Information System (INIS)

    Salcman, M.; Neuberth, G.; Nudelman, R.W.; Ferraro, F.T.; Hartman, M.

    1986-01-01

    Interstitial microwave hyperthermia may prove to be an important therapy for malignant brain tumors. For safety and efficiency, the size and number of intracranial microwave antennas needs to be limited. Low power swept frequency measurements of VSWR were carried out in the brains of anesthetized cats and dogs utilizing stereotactically placed monopole antennas. The coupling efficiency of antennas at any frequency was degraded (VSWR>2:1) if a length of antenna less than 2h was inserted or if a plastic catheter was utilized. Such measurements indicate that (h) can be shortened 25% from the resonant length without seriously degrading antenna performance. The total length can be halved if a catheter with a high dielectric is used. High power tests (2-10w) of short antennas at 915 MHz in a ceramic catheter (e = 10) at 45-50 0 C produce thermal fields approximately 2 cm in diameter in normal brain. It should be possible to efficiently and safely heat human brain tumors of average size utilizing these antennas and catheters at 915 MHz

  10. Plasmonic and Dielectric Metasurfaces: Design, Fabrication and Applications

    Directory of Open Access Journals (Sweden)

    Jian Wang

    2016-09-01

    Full Text Available Two-dimensional metasurfaces are widely focused on for their ability for flexible light manipulation (phase, amplitude, polarization over sub-wavelength propagation distances. Most of the metasurfaces can be divided into two categories by the material type of unit structure, i.e., plasmonic metasurfaces and dielectric metasurfaces. For plasmonic metasurfaces, they are made on the basis of metallic meta-atoms whose optical responses are driven by the plasmon resonances supported by metallic particles. For dielectric metasurfaces, the unit structure is constructed with high refractive index dielectric resonators, such as silicon, germanium or tellurium, which can support electric and magnetic dipole responses based on Mie resonances. The responses of plasmonic and dielectric metasurfaces are all relevant to the characteristics of unit structure, such as dimensions and materials. One can manipulate the electromagnetic field of light wave scattered by the metasurfaces through designing the dimension parameters of each unit structure in the metasurfaces. In this review article, we give a brief overview of our recent progress in plasmonic and dielectric metasurface-assisted nanophotonic devices and their design, fabrication and applications, including the metasurface-based broadband and the selective generation of orbital angular momentum (OAM carrying vector beams, N-fold OAM multicasting using a V-shaped antenna array, a metasurface on conventional optical fiber facet for linearly-polarized mode (LP11 generation, graphene split-ring metasurface-assisted terahertz coherent perfect absorption, OAM beam generation using a nanophotonic dielectric metasurface array, as well as Bessel beam generation and OAM multicasting using a dielectric metasurface array. It is believed that metasurface-based nanophotonic devices are one of the devices with the most potential applied in various fields, such as beam steering, spatial light modulator, nanoscale

  11. 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.

  12. Benchmark simulations of ICRF antenna coupling

    International Nuclear Information System (INIS)

    Louche, F.; Lamalle, P. U.; Messiaen, A. M.; Compernolle, B. van; Milanesio, D.; Maggiora, R.

    2007-01-01

    The paper reports on ongoing benchmark numerical simulations of antenna input impedance parameters in the ion cyclotron range of frequencies with different coupling codes: CST Microwave Studio, TOPICA and ANTITER 2. In particular we study the validity of the approximation of a magnetized plasma slab by a dielectric medium of suitably chosen permittivity. Different antenna models are considered: a single-strap antenna, a 4-strap antenna and the 24-strap ITER antenna array. Whilst the diagonal impedances are mostly in good agreement, some differences between the mutual terms predicted by Microwave Studio and TOPICA have yet to be resolved

  13. Quality Factor and Radiation Efficiency of Dual-Mode Self-Resonant Spherical Antennas With Lossy Magnetodielectric Cores

    DEFF Research Database (Denmark)

    Hansen, Troels Vejle; Kim, Oleksiy S.; Breinbjerg, Olav

    2014-01-01

    For spherical antennas consisting of a solid magnetodielectric lossy core with an impressed surface current density exciting a superposition of the ${\\rm TE}_{mn}$ and ${\\rm TM}_{mn}$ spherical modes, we analytically determine the radiation quality factor $Q$ and radiation efficiency $e$ . Also, we...

  14. A Low-Profile Dual-Layer Patch Antenna with a Circular Polarizer Consisting of Dual Semicircular Resonators

    Directory of Open Access Journals (Sweden)

    Li Guo

    2018-06-01

    Full Text Available In this paper, a circular polarizer comprising dual semicircular split-rings (DSSRs is presented. By placing it above an elliptical radiator that radiates linearly polarized (LP waves, dual-layer patch antennas capable of radiating right-hand (RH or left-hand (LH circularly polarized (CP waves are achieved in terms of the different offset direction of the bottom splits of the DSSRs. Because of both the capacitive coupling to the radiator and the degenerate modes existing in the excited DSSRs, the DSSRs collaboratively result in a circularly polarized radiation, successfully converting incident LP waves into CP ones. Simulated results show that the impedance, axial ratio (AR, and gain frequency response of both proposed CP antennas are identical, with a simulated 3-dB AR bandwidth of 72 MHz covering 2.402–2.474 GHz and a gain enhanced by 3.9 dB. The proposed antennas were fabricated and measured, revealing an operational bandwidth of 65 MHz (2.345–2.41 GHz and a peak gain up to 9 dBi. Moreover, a low profile of 0.063λ0 is maintained. The proposed CP antennas could be as a candidate for wireless target detection applications in terms of their identical frequency response property.

  15. 3D printed helical antenna with lens

    KAUST Repository

    Farooqui, Muhammad Fahad; Shamim, Atif

    2016-01-01

    of 3D and 2D inkjet printing of dielectric and metallic inks respectively, we demonstrate a Fresnel lens that has been monolithically integrated to a non-planar antenna (helix) for the first time. Antenna measurements show that the integration of a

  16. Waveguide Phased Array Antenna Analysis and Synthesis

    NARCIS (Netherlands)

    Visser, H.J.; Keizer, W.P.M.N.

    1996-01-01

    Results of two software packages for analysis and synthesis of waveguide phased array antennas are shown. The antennas consist of arrays of open-ended waveguides where irises can be placed in the waveguide apertures and multiple dielectric sheets in front of the apertures in order to accomplish a

  17. Optical characterization of Jerusalem cross-shaped nanoaperture antenna arrays

    Science.gov (United States)

    Turkmen, Mustafa; Aslan, Ekin; Aslan, Erdem

    2014-03-01

    Recent advances in nanofabrication and computational electromagnetic design techniques have enabled the realization of metallic nanostructures in different shapes and sizes with adjustable resonance frequencies. To date, many metamaterial designs in various geometries with the used of different materials have been presented for the applications of surface plasmons, cloaking, biosensing, and frequency selective surfaces1-5. Surface plasmons which are collective electron oscillations on metal surfaces ensure that plasmonic nanoantennas can be used in many applications like biosensing at infrared (IR) and visible regions. The nanostructure that we introduce has a unit cell that consists of Jerusalem crossshaped nanoaperture on a gold layer, which is standing on suspended SiNx, Si or glass membranes. The proposed nanoaperture antenna array has a regular and stable spectral response. In this study, we present sensitivity of the resonance characteristics of Jerusalem cross-shaped nanoaperture antenna arrays to the changes in substrate parameters and metal thickness. We demonstrate that resonance frequency values can be adjusted by changing the thicknesses and types of the dielectric substrate and the metallic layer. Numerical calculations on spectral response of the nanoantenna array are performed by using Finite Difference Time Domain (FDTD) method6. The results of the simulations specify that resonance frequencies, the reflectance and transmittance values at resonances, and the band gap vary by the change of substrate parameters and metal thicknesses. These variations is a sign of that the proposed nanoantenna can be employed for sensing applications.

  18. Combined antenna and localized plasmon resonance in Raman scattering from random arrays of silver-coated, vertically aligned multiwalled carbon nanotubes.

    Science.gov (United States)

    Dawson, P; Duenas, J A; Boyle, M G; Doherty, M D; Bell, S E J; Kern, A M; Martin, O J F; Teh, A-S; Teo, K B K; Milne, W I

    2011-02-09

    The electric field enhancement associated with detailed structure within novel optical antenna nanostructures is modeled using the surface integral equation technique in the context of surface-enhanced Raman scattering (SERS). The antennae comprise random arrays of vertically aligned, multiwalled carbon nanotubes dressed with highly granular Ag. Different types of "hot-spot" underpinning the SERS are identified, but contrasting characteristics are revealed. Those at the outer edges of the Ag grains are antenna driven with field enhancement amplified in antenna antinodes while intergrain hotspots are largely independent of antenna activity. Hot-spots between the tops of antennae leaning towards each other also appear to benefit from antenna amplification.

  19. Modelling of radio frequency sheath and fast wave coupling on the realistic ion cyclotron resonant antenna surroundings and the outer wall

    Science.gov (United States)

    Lu, L.; Colas, L.; Jacquot, J.; Després, B.; Heuraux, S.; Faudot, E.; Van Eester, D.; Crombé, K.; Křivská, A.; Noterdaeme, J.-M.; Helou, W.; Hillairet, J.

    2018-03-01

    In order to model the sheath rectification in a realistic geometry over the size of ion cyclotron resonant heating (ICRH) antennas, the self-consistent sheaths and waves for ICH (SSWICH) code couples self-consistently the RF wave propagation and the DC SOL biasing via nonlinear RF and DC sheath boundary conditions applied at plasma/wall interfaces. A first version of SSWICH had 2D (toroidal and radial) geometry, rectangular walls either normal or parallel to the confinement magnetic field B 0 and only included the evanescent slow wave (SW) excited parasitically by the ICRH antenna. The main wave for plasma heating, the fast wave (FW) plays no role on the sheath excitation in this version. A new version of the code, 2D SSWICH-full wave, was developed based on the COMSOL software, to accommodate full RF field polarization and shaped walls tilted with respect to B 0 . SSWICH-full wave simulations have shown the mode conversion of FW into SW occurring at the sharp corners where the boundary shape varies rapidly. It has also evidenced ‘far-field’ sheath oscillations appearing at the shaped walls with a relatively long magnetic connection length to the antenna, that are only accessible to the propagating FW. Joint simulation, conducted by SSWICH-full wave within a multi-2D approach excited using the 3D wave coupling code (RAPLICASOL), has recovered the double-hump poloidal structure measured in the experimental temperature and potential maps when only the SW is modelled. The FW contribution on the potential poloidal structure seems to be affected by the 3D effects, which was ignored in the current stage. Finally, SSWICH-full wave simulation revealed the left-right asymmetry that has been observed extensively in the unbalanced strap feeding experiments, suggesting that the spatial proximity effects in RF sheath excitation, studied for SW only previously, is still important in the vicinity of the wave launcher under full wave polarizations.

  20. Compact Low Frequency Radio Antenna

    Science.gov (United States)

    Punnoose, Ratish J.

    2008-11-11

    An antenna is disclosed that comprises a pair of conductive, orthogonal arches and a pair of conductive annular sector plates, wherein adjacent legs of each arch are fastened to one of the annular sector plates and the opposite adjacent pair of legs is fastened to the remaining annular sector plate. The entire antenna structure is spaced apart from a conductive ground plane by a thin dielectric medium. The antenna is driven by a feed conduit passing through the conductive ground plane and dielectric medium and attached to one of the annular sector plates, wherein the two orthogonal arched act as a pair of crossed dipole elements. This arrangement of elements provides a radiation pattern that is largely omni-directional above the horizon.

  1. Minimum Q Electrically Small Antennas

    DEFF Research Database (Denmark)

    Kim, O. S.

    2012-01-01

    Theoretically, the minimum radiation quality factor Q of an isolated resonance can be achieved in a spherical electrically small antenna by combining TM1m and TE1m spherical modes, provided that the stored energy in the antenna spherical volume is totally suppressed. Using closed-form expressions...... for a multiarm spherical helix antenna confirm the theoretical predictions. For example, a 4-arm spherical helix antenna with a magnetic-coated perfectly electrically conducting core (ka=0.254) exhibits the Q of 0.66 times the Chu lower bound, or 1.25 times the minimum Q....

  2. Characterization and study of dielectric and electrical properties of CaBi4Ti4O_1_5 (CBT) added with Bi_2O_3

    International Nuclear Information System (INIS)

    Freitas, D.B.; Campos Filho, M.C.; Sales, J.C.; Silva, P.M.O.; Sombra, A.S.

    2011-01-01

    The ceramic perovskite CaBi_4Ti_4O_1_5 (CBT) of space group A21am, Aurivillius family with deficiency A_5B_4O_1_5 cation has been prepared by solid state method in a planetary ball mill of high energy. The reagents samples were ground and calcined and then added with Bi_2O_3 (2% wt.) This work aims to characterize by X-ray diffraction to study the electrical properties and dielectric properties of (CBT). The x-ray diffraction revealed the formation of single orthorhombic phase. As for the dielectric properties (dielectric constant and dielectric loss) were measured at 30 deg C to 450 deg C, through which can be verified the presence of thermally activated processes. This phase has properties very relevant for possible use in capacitive devices, miniaturized filters, dielectric resonators antennas and oscillators. (author)

  3. Fano-like resonance and scattering in dielectric(core)–metal(shell) composites embedded in active host matrices

    CSIR Research Space (South Africa)

    Jule, L

    2015-07-01

    Full Text Available We investigate light scattering by core–shell consisting of metal/dielectric composites considering spherical and cylindrical nanoinclusions, within the framework of the conventional Rayleigh approximation. By writing the electric potential...

  4. Wireless interrogation of passive antenna sensors

    International Nuclear Information System (INIS)

    Deshmukh, S; Huang, H

    2010-01-01

    Recently, we discovered that the resonant frequency of a microstrip patch antenna is sensitive to mechanical strains or crack presence in the ground plane. Based on this principle, antenna sensors have been demonstrated to measure strain and detect crack in metallic structures. This paper presents a wireless method to remotely interrogate a dual-frequency antenna sensor. An interrogation horn antenna was used to irradiate the antenna sensor with a linear chirp microwave signal. By implementing a light-activated switch at the sensor node and performing signal processing of the backscattered signals, the resonant frequencies of the antenna sensor along both polarizations can be measured remotely. Since the antenna sensor does not need a local power source and can be interrogated wirelessly, electric wiring can be eliminated. The sensor implementation, the signal processing and the experimental setup that validate the remote interrogation of the antenna sensor are presented. A power budget model has also been established to estimate the maximum interrogation range

  5. Artificial Material Integrated Ultra-wideband Tapered Slot Antenna for Gain Enhancement with Band Notch Characteristics

    Directory of Open Access Journals (Sweden)

    R. Singha

    2018-04-01

    Full Text Available The gain of the ultra-wideband tapered slot antenna (TSA is enhanced by using broadband artificial material with band notch characteristics. The proposed artificial material unit cell is designed by fabricating non-resonant three S-shaped parallel metallic line on single side of the dielectric substrate which provides a longer current path compared to the parallel-line structure. The proposed S-shaped structure is printed on the top side of the tapered slot antenna in the extended substrate periodically. The effective refractive index of the artificial material is lower than antenna substrate and phase velocity in the region of artificial material is much higher than the other region. Therefore, the proposed artificial material acts like a beam focusing lens. The band notch at 5.5 GHz is achieved by creating a split ring resonator (SRR slot near the balun. The basic and artificial material loaded TSAs are fabricated and the measurement results show that the gain of the basic antenna has been increased by 1.6 dBi. At the same time, the proposed antenna achieves a VSWR below 2 from 3 to 11 GHz except at 5.5 GHz with a notch band from 5.1 to 5.8 GHz for band rejection of wireless local area network (WLAN application.

  6. Design and investigation of planar technology based ultra-wideband antenna with directional radiation patterns

    Energy Technology Data Exchange (ETDEWEB)

    Meena, M. L., E-mail: madan.meena.ece@gamil.com; Parmar, Girish, E-mail: girish-parmar2002@yahoo.com; Kumar, Mithilesh, E-mail: mith-kr@yahoo.com [Department of Electronics Engineering, Rajasthan Technical University, Kota (India)

    2016-03-09

    A novel design technique based on planar technology for ultra-wideband (UWB) antennas with different ground shape having directional radiation pattern is being presented here. Firstly, the L-shape corner reflector ground plane antenna is designed with microstrip feed line in order to achieve large bandwidth and directivity. Thereafter, for the further improvement in the directivity as well as for better impedance matching the parabolic-shape ground plane has been introduced. The coaxial feed line is given for the proposed directional antenna in order to achieve better impedance matching with 50 ohm transmission line. The simulation analysis of the antenna is done on CST Microwave Studio software using FR-4 substrate having thickness of 1.6 mm and dielectric constant of 4.4. The simulated result shows a good return loss (S11) with respect to -10 dB. The radiation pattern characteristic, angular width, directivity and bandwidth performance of the antenna have also been compared at different resonant frequencies. The designed antennas exhibit low cost, low reflection coefficient and better directivity in the UWB frequency band.

  7. A Miniaturized Antenna with Negative Index Metamaterial Based on Modified SRR and CLS Unit Cell for UWB Microwave Imaging Applications

    Directory of Open Access Journals (Sweden)

    Md. Moinul Islam

    2015-01-01

    Full Text Available A miniaturized antenna employing a negative index metamaterial with modified split-ring resonator (SRR and capacitance-loaded strip (CLS unit cells is presented for Ultra wideband (UWB microwave imaging applications. Four left-handed (LH metamaterial (MTM unit cells are located along one axis of the antenna as the radiating element. Each left-handed metamaterial unit cell combines a modified split-ring resonator (SRR with a capacitance-loaded strip (CLS to obtain a design architecture that simultaneously exhibits both negative permittivity and negative permeability, which ensures a stable negative refractive index to improve the antenna performance for microwave imaging. The antenna structure, with dimension of 16 × 21 × 1.6 mm3, is printed on a low dielectric FR4 material with a slotted ground plane and a microstrip feed. The measured reflection coefficient demonstrates that this antenna attains 114.5% bandwidth covering the frequency band of 3.4–12.5 GHz for a voltage standing wave ratio of less than 2 with a maximum gain of 5.16 dBi at 10.15 GHz. There is a stable harmony between the simulated and measured results that indicate improved nearly omni-directional radiation characteristics within the operational frequency band. The stable surface current distribution, negative refractive index characteristic, considerable gain and radiation properties make this proposed negative index metamaterial antenna optimal for UWB microwave imaging applications.

  8. Optimized dipole antennas on photonic band gap crystals

    International Nuclear Information System (INIS)

    Cheng, S.D.; Biswas, R.; Ozbay, E.; McCalmont, S.; Tuttle, G.; Ho, K.

    1995-01-01

    Photonic band gap crystals have been used as a perfectly reflecting substrate for planar dipole antennas in the 12--15 GHz regime. The position, orientation, and driving frequency of the dipole antenna on the photonic band gap crystal surface, have been optimized for antenna performance and directionality. Virtually no radiated power is lost to the photonic crystal resulting in gains and radiation efficiencies larger than antennas on other conventional dielectric substrates. copyright 1995 American Institute of Physics

  9. Dynamics of asymmetric non-polymeric binary glass formers—A nuclear magnetic resonance and dielectric spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Pötzschner, B.; Mohamed, F.; Lichtinger, A.; Bock, D.; Rössler, E. A., E-mail: ernst.roessler@uni-bayreuth.de [Experimentalphysik II, Universität Bayreuth, 95440 Bayreuth (Germany)

    2015-10-21

    We study a dynamically asymmetric binary glass former with the low-T{sub g} component m-tri-cresyl phosphate (m-TCP: T{sub g} = 206 K) and a spirobichroman derivative as a non-polymeric high-T{sub g} component (T{sub g} = 382 K) by means of {sup 1}H nuclear magnetic resonance (NMR), {sup 31}P NMR, and dielectric spectroscopy which allow component-selectively probing the dynamics. The entire concentration range is covered, and two main relaxation processes with two T{sub g} are identified, T{sub g1} and T{sub g2}. The slower one is attributed to the high-T{sub g} component (α{sub 1}-process), and the faster one is related to the m-TCP molecules (α{sub 2}-process). Yet, there are indications that a small fraction of m-TCP is associated also with the α{sub 1}-process. While the α{sub 1}-relaxation only weakly broadens upon adding m-TCP, the α{sub 2}-relaxation becomes extremely stretched leading to quasi-logarithmic correlation functions at low m-TCP concentrations—as probed by {sup 31}P NMR stimulated echo experiments. Frequency-temperature superposition does not apply for the α{sub 2}-process and it reflects an isotropic, liquid-like motion which is observed even below T{sub g1}, i.e., in the matrix of the arrested high-T{sub g} molecules. As proven by 2D {sup 31}P NMR, the corresponding dynamic heterogeneities are of transient nature, i.e., exchange occurs within the distribution G(lnτ{sub α2}). At T{sub g1} a crossover is found for the temperature dependence of (mean) τ{sub α2}(T) from non-Arrhenius above to Arrhenius below T{sub g1} which is attributed to intrinsic confinement effects. This “fragile-to-strong” transition also leads to a re-decrease of T{sub g2}(c{sub m−TCP}) at low concentration c{sub m−TCP}, i.e., a maximum is observed in T{sub g2}(c{sub m−TCP}) while T{sub g1}(c{sub m−TCP}) displays the well-known plasticizer effect. Although only non-polymeric components are involved, we re-discover essentially all features previously

  10. Low-Q Electrically Small Spherical Magnetic Dipole Antennas

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.

    2010-01-01

    Three novel electrically small antenna configurations radiating a TE10 spherical mode corresponding to a magnetic dipole are presented and investigated: multiarm spherical helix (MSH) antenna, spherical split ring resonator (S-SRR) antenna, and spherical split ring (SSR) antenna. All three antennas...... are self-resonant, with the input resistance tuned to 50 ohms by an excitation curved dipole/monopole. A prototype of the SSR antenna has been fabricated and measured, yielding results that are consistent with the numerical simulations. Radiation quality factors (Q) of these electrically small antennas (in...

  11. Experimental validation of an ultra-thin metasurface cloak for hiding a metallic obstacle from an antenna radiation at low frequencies

    Science.gov (United States)

    Teperik, Tatiana V.; Burokur, Shah Nawaz; de Lustrac, André; Sabanowski, Guy; Piau, Gérard-Pascal

    2017-07-01

    We demonstrate numerically and experimentally an ultra-thin (≈ λ/240) metasurface-based invisibility cloak for low frequency antenna applications. We consider a monopole antenna mounted on a ground plane and a cylindrical metallic obstacle of diameter smaller than the wavelength located in its near-field. To restore the intrinsic radiation patterns of the antenna perturbed by this obstacle, a metasurface cloak consisting simply of a metallic patch printed on a dielectric substrate is wrapped around the obstacle. Using a finite element method based commercial electromagnetic solver, we show that the radiation patterns of the monopole antenna can be restored completely owing to electromagnetic modes of the resonant cavity formed between the patch and obstacle. The metasurface cloak is fabricated, and the concept is experimentally demonstrated at 125 MHz. Performed measurements are in good agreement with numerical simulations, verifying the efficiency of the proposed cloak.

  12. CPW to CPS transition for feeding UWB antennas

    DEFF Research Database (Denmark)

    Butrym, Alexander; Pivnenko, Sergey

    2004-01-01

    The paper considers a transition (balun) from Coplanar Waveguide (CPW) to Coplanar Stripline (CPS) which is non-resonant and suitable for feeding UWB antennas such as Tapered Slot Antennas (Vivaldi antennas in particular), bow-tie antennas, and other. Some numerical and experimental results...

  13. CPW to CPS transition for feeding UWB antennas

    DEFF Research Database (Denmark)

    Butrym, Alexander; Pivnenko, Sergey

    2006-01-01

    The paper considers a transition (balun) from Coplanar Waveguide (CPW) to Coplanar Stripline (CPS) which is non-resonant and suitable for feeding UWB antennas such as Tapered Slot Antennas (Vivaldi antennas, in particular), bow-tie antennas, and other. Some numerical and experimental results...

  14. Tri-band small monopole antenna based on SRR units

    Directory of Open Access Journals (Sweden)

    Gehan Shehata

    2015-12-01

    Full Text Available In this paper a novel design for a tri-band monopole antenna coupled with metamaterial units is introduced. The proposed antenna was designed to cover WiMAX (2.5, 3.5 and WLAN (5.2 bands. In our proposal, a coplanar waveguide (CPW fed circular-disk monopole antenna is coupled with three split ring resonator (SRR units which exist on its back side. In our design a monopole antenna and SRR units are designed first to resonate at 5.2 GHz and 2.5 GHz respectively. In addition, antenna is loaded with post to force resonance at 3.5 GHz. SRR units are used for 2.5 GHz resonance to miniaturize antenna size, and our proposed antenna considered an electrically small antenna (ESA at its first resonance frequency. Simulated and measured results exhibit a good agreement that validate our design.

  15. A simple solution for reducing artefacts due to conductive and dielectric effects in clinical magnetic resonance imaging at 3 T

    International Nuclear Information System (INIS)

    Sreenivas, M.; Lowry, M.; Gibbs, P.; Pickles, M.; Turnbull, L.W.

    2007-01-01

    The quality of imaging obtained at high magnetic field strengths can be degraded by various artefacts due to conductive and dielectric effects, which leads to loss of signal. Various methods have been described and used to improve the quality of the image affected by such artefacts. In this article, we describe the construction and use of a simple solution that can be used to diminish artefacts due to conductive and dielectric effects in clinical imaging at 3 T field strength and thereby improve the diagnostic quality of the images obtained

  16. A simple solution for reducing artefacts due to conductive and dielectric effects in clinical magnetic resonance imaging at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Sreenivas, M. [Department of Radiology (Yorkshire Deanery-East), Hull Royal Infirmary, Anlaby Road, Hull HU3 2JZ (United Kingdom)]. E-mail: aprilsreenivas@hotmail.com; Lowry, M. [Centre for Magnetic Resonance Investigations, University of Hull, Hull Royal Infirmary, Anlaby Road, 1PR, Hull HU3 2JZ (United Kingdom); Gibbs, P. [Centre for Magnetic Resonance Investigations, University of Hull, Hull Royal Infirmary, Anlaby Road, 1PR, Hull HU3 2JZ (United Kingdom); Pickles, M. [Centre for Magnetic Resonance Investigations, University of Hull, Hull Royal Infirmary, Anlaby Road, 1PR, Hull HU3 2JZ (United Kingdom); Turnbull, L.W. [Centre for Magnetic Resonance Investigations, University of Hull, Hull Royal Infirmary, Anlaby Road, 1PR, Hull HU3 2JZ (United Kingdom)

    2007-04-15

    The quality of imaging obtained at high magnetic field strengths can be degraded by various artefacts due to conductive and dielectric effects, which leads to loss of signal. Various methods have been described and used to improve the quality of the image affected by such artefacts. In this article, we describe the construction and use of a simple solution that can be used to diminish artefacts due to conductive and dielectric effects in clinical imaging at 3 T field strength and thereby improve the diagnostic quality of the images obtained.

  17. Antenna toolkit

    CERN Document Server

    Carr, Joseph

    2006-01-01

    Joe Carr has provided radio amateurs and short-wave listeners with the definitive design guide for sending and receiving radio signals with Antenna Toolkit 2nd edition.Together with the powerful suite of CD software, the reader will have a complete solution for constructing or using an antenna - bar the actual hardware! The software provides a simple Windows-based aid to carrying out the design calculations at the heart of successful antenna design. All the user needs to do is select the antenna type and set the frequency - a much more fun and less error prone method than using a con

  18. Elementary electron-molecule interactions and negative ion resonances at subexcitation energies and their significance in gaseous dielectrics

    International Nuclear Information System (INIS)

    Christophorou, L.G.

    1977-01-01

    Recent knowledge on low-energy (mostly approximately less than 10 eV) electron-molecule interaction processes in dilute and in dense gases is synthesized, discussed, and related to the breakdown strength of gaseous dielectrics. Optimal design of multicomponent gaseous insulators can be made on the basis of such knowledge

  19. Novel ring resonator-based integrated photonic beamformer for broadband phased array receive antennas - part 2: experimental prototype

    NARCIS (Netherlands)

    Zhuang, L.; Roeloffzen, C.G.H.; Meijerink, Arjan; Burla, M.; Marpaung, D.A.I.; Leinse, Arne; Hoekman, M.; Heideman, Rene; van Etten, Wim

    2010-01-01

    An experimental prototype is presented that illustrates the implementation aspects and feasibility of the novel ring resonator-based optical beamformer concept that has been developed and analyzed in Part I of this paper . This concept can be used for seamless control of the reception angle in

  20. Analysis of Microstrip Line Fed Patch Antenna for Wireless Communications

    Directory of Open Access Journals (Sweden)

    Singh Ashish

    2017-11-01

    Full Text Available In this paper, theoretical analysis of microstrip line fed rectangular patch antenna loaded with parasitic element and split-ring resonator is presented. The proposed antenna shows that the dualband operation depends on gap between parasitic element, split-ring resonator, length and width of microstrip line. It is found that antenna resonates at two distinct resonating modes i.e., 0.9 GHz and 1.8 GHz for lower and upper resonance frequencies respectively. The antenna shows dual frequency nature with frequency ratio 2.0. The characteristics of microstrip line fed rectangular patch antenna loaded with parasitic element and split-ring resonator antenna is compared with other prototype microstrip line fed antennas. Further, the theoretical results are compared with simulated and reported experimental results, they are in close agreement.

  1. Directional Emission from Dielectric Leaky-Wave Nanoantennas

    Science.gov (United States)

    Peter, Manuel; Hildebrandt, Andre; Schlickriede, Christian; Gharib, Kimia; Zentgraf, Thomas; Förstner, Jens; Linden, Stefan

    2017-07-01

    An important source of innovation in nanophotonics is the idea to scale down known radio wave technologies to the optical regime. One thoroughly investigated example of this approach are metallic nanoantennas which employ plasmonic resonances to couple localized emitters to selected far-field modes. While metals can be treated as perfect conductors in the microwave regime, their response becomes Drude-like at optical frequencies. Thus, plasmonic nanoantennas are inherently lossy. Moreover, their resonant nature requires precise control of the antenna geometry. A promising way to circumvent these problems is the use of broadband nanoantennas made from low-loss dielectric materials. Here, we report on highly directional emission from active dielectric leaky-wave nanoantennas made of Hafnium dioxide. Colloidal semiconductor quantum dots deposited in the nanoantenna feed gap serve as a local light source. The emission patterns of active nanoantennas with different sizes are measured by Fourier imaging. We find for all antenna sizes a highly directional emission, underlining the broadband operation of our design.

  2. Development of a new prototype system for measuring the permittivity of dielectric materials

    Directory of Open Access Journals (Sweden)

    Jiajia Jiang

    2014-06-01

    Full Text Available A simple prototype for measuring the properties of dielectric materials is introduced in this Letter. A homogeneous dielectric sample placed in a field produced by a nearby antenna will affect the input impedance of the antenna. The permittivity and the loss of the dielectric sample can then be determined from the change of the input impedance of the antenna. The prototype has been validated by experiments.

  3. Microwave Metamaterial-Based Sensor for Dielectric Characterization of Liquids.

    Science.gov (United States)

    Soffiatti, André; Max, Yuri; G Silva, Sandro; M de Mendonça, Laércio

    2018-05-11

    This article proposed to build a system founded on metamaterial sensor antennas, which can be used to evaluate impurities in aqueous substances according to the quality of transmission between the sensor antennas. In order to do this, a dedicated setup with tests in several frequencies was deployed so as to monitor the behavior of transmission variation between sensors. These sensors are microstrip antennas with a ground plane of resonant cleaved metallic rings; the substrate functions as a metamaterial for the irradiating element. In this study, an analysis was made of transmission between the sensors, looking for variation in angles of incidence of signal and of distance between the antennas. The sensor was tested at various operating frequencies, as such 1.8 GHz, 2.4 GHz, 3.4 GHz and 4.1 GHz, resulting in different values of sensitivity. The prototypes were constructed and tested so as to analyze the dielectric effects of the impurities on NaCl and C₂H₄O₂ substances. The research aims to use these control systems of impurities in industrial premises.

  4. 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%.

  5. The ICRF antennas for TFTR

    International Nuclear Information System (INIS)

    Hoffman, D.J.; Colestock, P.L.; Gardner, W.L.; Hosea, J.C.; Nagy, A.; Stevens, J.; Swain, D.W.; Wilson, J.R.

    1988-01-01

    Two compact loop antennas have been designed to provide ion cyclotron resonant frequency (ICRF) heating for TFTR. The antennas can convey a total of 10 MW to accomplish core heating in either high-density or high-temperature plasmas. The near-term goal of heating TFTR plasmas and the longer-term goals of ease in handling (for remote maintenance) and high reliability (in an inaccessible tritium tokamak environment) were major considerations in the antenna designs. The compact loop configuration facilitates handling because the antennas fit completely through their ports. Conservative design and extensive testing were used to attain the reliability required for TFTR. This paper summarizes how these antennas will accomplish these goals. 5 figs, 1 tab

  6. A new metasurface reflective structure for simultaneous enhancement of antenna bandwidth and gain

    International Nuclear Information System (INIS)

    Habib Ullah, M; Islam, M T

    2014-01-01

    A new bi-layered metasurface reflective structure (MRS) on a high-permittivity, low-loss, ceramic-filled, bio-plastic, sandwich-structured, dielectric substrate is proposed for the simultaneous enhancement of the bandwidth and gain of a dual band patch antenna. By incorporating the MRS with a 4 mm air gap between the MRS and the antenna, the bandwidth and gain of the dual band patch antenna are significantly enhanced. The reflection coefficient (S11 < −10 dB) bandwidth of the proposed MRS-loaded antenna increased by 240% (178%), and the average peak gain improved by 595% (128%) compared to the antenna alone in the lower (upper) band. Incremental improvements of the magnitude and directional patterns have been observed from the measured radiation patterns at the three resonant frequencies of 0.9 GHz, 3.7 GHz and 4.5 GHz. The effects of different configurations of the radiating patch and the ground plane on the reflection coefficient have been analyzed. In addition, the voltage standing wave ratio and input impedance have also been validated using a Smith chart. (paper)

  7. A new metasurface reflective structure for simultaneous enhancement of antenna bandwidth and gain

    Science.gov (United States)

    Ullah, M. Habib; Islam, M. T.

    2014-08-01

    A new bi-layered metasurface reflective structure (MRS) on a high-permittivity, low-loss, ceramic-filled, bio-plastic, sandwich-structured, dielectric substrate is proposed for the simultaneous enhancement of the bandwidth and gain of a dual band patch antenna. By incorporating the MRS with a 4 mm air gap between the MRS and the antenna, the bandwidth and gain of the dual band patch antenna are significantly enhanced. The reflection coefficient (S11 < -10 dB) bandwidth of the proposed MRS-loaded antenna increased by 240% (178%), and the average peak gain improved by 595% (128%) compared to the antenna alone in the lower (upper) band. Incremental improvements of the magnitude and directional patterns have been observed from the measured radiation patterns at the three resonant frequencies of 0.9 GHz, 3.7 GHz and 4.5 GHz. The effects of different configurations of the radiating patch and the ground plane on the reflection coefficient have been analyzed. In addition, the voltage standing wave ratio and input impedance have also been validated using a Smith chart.

  8. Field and ray analyses of antenna excitations in ICRF heating of large Tokamaks

    International Nuclear Information System (INIS)

    Bers, A.; Lister, G.; Jacquinot, J.

    1980-09-01

    We present analytical and computational techniques for determining the electromagnetic fields and associated power flow excited by antenna systems external to large Tokamak plasmas. The finite poloidal and toroidal extension of the poloidal antenna current is modeled by a superposition of current sheets placed at a fixed radius outside the plasma. Antennae both with and without a screen between the current sheet and the plasma are considered. The plama is modeled by its cold dielectric tensor and inhomogeneous density and applied magnetic field. For large Tokamak plasmas in which the plasma dimensions are large compared to the antenna, the field excitation problem can be considered approximately in slab geometry. The field solution of this problem which we present, gives the electromagnetic fields excited in the edge plasma by the antennae and includes the effect of the cutoffs which may exist in this region. To proceed further into the plasma we consider a ray tracing analysis. Starting from an equiphase surface of the excited fields in the edge plasma, the group velocity rays can be followed in full toroidal geometry up to the cyclotron singular resonance region where the power is deposited in the particles. Both the amplitude and phase of the fields can be established in the vicinity of the angular surface so that the power deposition profile can be eventually calculated

  9. Antenna Parts and Waveguide Transmission Line of Short Pulse Radar System Design

    Directory of Open Access Journals (Sweden)

    M. E. Golubcov

    2014-01-01

    Full Text Available The main point of this research was работы являлось to create a stand to explore the application of short pulse radio signals in radar. The stand consists of antenna and waveguide elements. Each element out to guarantee operation in X-band with 10 percent working bank and 5 percent instantaneous bandwidth and the power output gotta be 1.5 kW. The form of the antenna beam patten need to be similar to cosecant pattern Side-lobe level need to be less than -25 dB. Background level got to be at least -30 dB. Wave friction, which is radiated from the antenna aperture, got to simultaneous formed in a space.As the most easily realizing variant of such antenna cutting parabolic mirror antenna with offset irradiator was chosen. The irradiator phase centre is shifted from the focal point of the paraboloid to form a cosecant pattern. Method of physical optics is used for the analysis of antennas. Calculating pattern of horn irradiator and mirror antenna which were met the requirements was received. The construction choice was limited by the preproduction possibilities, mass and dimensions. Mirror antenna consists of skeleton framing with mirroring elements which are fixing on it. Mirroring plane is multiplex and consists off rectangular planes made by hydroforming method. Antenna was tested and adjusted at the antenna darkroom after fabricating. The results were meted requirements.Besides the mirror antenna and the horn antenna waveguide elements, waveguide bends and rotating joints were calculated, manufactured and researched. All calculations included the manufacturers tolerances, technological corner R etc. As the construction base of rotating joint coaxial waveguide was chosen. The decision on the one hand: let keep the axial symmetry of excited wave at rotating part of the waveguide, on the other hand there’s no necessary to apply resonant rings, which are plug into dielectric beads for the transition from rotating ring part to

  10. Elliptical metasurfaces for cloaking and antenna applications at microwave and terahertz frequencies

    Science.gov (United States)

    Mehrpourbernety, Hossein

    One of the interesting applications of metamaterials is the phenomenon of electromagnetic invisibility and cloaking, which implies the suppression of bistatic scattering width of a given object, independent of incident and observation angles. In this regard, diverse techniques have been proposed to analyze and design electromagnetic cloak structures, including transformation optics, anomalous resonance methods, transmission-line networks, and plasmonic cloaking, among others. A common drawback of all these methods is that they rely on bulk materials, which are difficult to realize in practice. To overcome this issue, the mantle cloaking method has been proposed, which utilizes an ultrathin metasurface that provides anti-phase surface currents to reduce the scattering dominant mode of a given object. Recently, an analytical model has been proposed to cloak dielectric and conducting cylindrical objects realized with printed and slotted arrays at microwave frequencies. At low-terahertz (THz) frequencies, one of the promising materials to realize the required metasurface is graphene. In this regard, a graphene monolayer, characterized by inductive reactance, has been proposed to cloak dielectric planar and cylindrical objects. Then, it has been shown that a metasurface made of graphene nanopatches owns dual capacitive/inductive inductance and can be used to cloak both dielectric and conducting cylindrical objects at low-THz frequencies. So far, planar and cylindrical dielectric and conducting structures have been studied. In our study, we have extended the concept and presented an accurate analytical approach to investigate the cloaking of two-dimensional (2-D) elliptical objects including infinite dielectric elliptical cylinders using graphene monolayer; metallic elliptical cylinders, and also, as a special case, 2-D metallic strips using a nanostructured graphene patch array at low-THz frequencies. We have also obtained the results for cloaking of ellipses at

  11. Integrated, Multi-Scale Characterization of Imbibition and Wettability Phenomena Using Magnetic Resonance and Wide-Band Dielectric Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Mukul M. Sharma; Steven L. Bryant; Carlos Torres-Verdin; George Hirasaki

    2007-09-30

    The petrophysical properties of rocks, particularly their relative permeability and wettability, strongly influence the efficiency and the time-scale of all hydrocarbon recovery processes. However, the quantitative relationships needed to account for the influence of wettability and pore structure on multi-phase flow are not yet available, largely due to the complexity of the phenomena controlling wettability and the difficulty of characterizing rock properties at the relevant length scales. This project brings together several advanced technologies to characterize pore structure and wettability. Grain-scale models are developed that help to better interpret the electric and dielectric response of rocks. These studies allow the computation of realistic configurations of two immiscible fluids as a function of wettability and geologic characteristics. These fluid configurations form a basis for predicting and explaining macroscopic behavior, including the relationship between relative permeability, wettability and laboratory and wireline log measurements of NMR and dielectric response. Dielectric and NMR measurements have been made show that the response of the rocks depends on the wetting and flow properties of the rock. The theoretical models can be used for a better interpretation and inversion of standard well logs to obtain accurate and reliable estimates of fluid saturation and of their producibility. The ultimate benefit of this combined theoretical/empirical approach for reservoir characterization is that rather than reproducing the behavior of any particular sample or set of samples, it can explain and predict trends in behavior that can be applied at a range of length scales, including correlation with wireline logs, seismic, and geologic units and strata. This approach can substantially enhance wireline log interpretation for reservoir characterization and provide better descriptions, at several scales, of crucial reservoir flow properties that govern oil

  12. Optical Dark-Field and Electron Energy Loss Imaging and Spectroscopy of Symmetry-Forbidden Modes in Loaded Nanogap Antennas.

    Science.gov (United States)

    Brintlinger, Todd; Herzing, Andrew A; Long, James P; Vurgaftman, Igor; Stroud, Rhonda; Simpkins, B S

    2015-06-23

    We have produced large numbers of hybrid metal-semiconductor nanogap antennas using a scalable electrochemical approach and systematically characterized the spectral and spatial character of their plasmonic modes with optical dark-field scattering, electron energy loss spectroscopy with principal component analysis, and full wave simulations. The coordination of these techniques reveal that these nanostructures support degenerate transverse modes which split due to substrate interactions, a longitudinal mode which scales with antenna length, and a symmetry-forbidden gap-localized transverse mode. This gap-localized transverse mode arises from mode splitting of transverse resonances supported on both antenna arms and is confined to the gap load enabling (i) delivery of substantial energy to the gap material and (ii) the possibility of tuning the antenna resonance via active modulation of the gap material's optical properties. The resonant position of this symmetry-forbidden mode is sensitive to gap size, dielectric strength of the gap material, and is highly suppressed in air-gapped structures which may explain its absence from the literature to date. Understanding the complex modal structure supported on hybrid nanosystems is necessary to enable the multifunctional components many seek.

  13. Fabrication of Antenna-Coupled KID Array for Cosmic Microwave Background Detection

    Science.gov (United States)

    Tang, Q. Y.; Barry, P. S.; Basu Thakur, R.; Kofman, A.; Nadolski, A.; Vieira, J.; Shirokoff, E.

    2018-05-01

    Kinetic inductance detectors (KIDs) have become an attractive alternative to traditional bolometers in the sub-mm and mm observing community due to their innate frequency multiplexing capabilities and simple lithographic processes. These advantages make KIDs a viable option for the O(500,000) detectors needed for the upcoming Cosmic Microwave Background-Stage 4 experiment. We have fabricated an antenna-coupled MKID array in the 150 GHz band optimized for CMB detection. Our design uses a twin-slot antenna coupled to an inverted microstrip made from a superconducting Nb/Al bilayer as the strip, a Nb ground plane and a SiN_x dielectric layer in between, which is then coupled to an Al KID grown on high-resistivity Si. We present the fabrication process and measurements of SiN_x microstrip resonators.

  14. 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 ...

  15. Modeling and Optimizing Antennas for Rotational Spectroscopy Applications

    Directory of Open Access Journals (Sweden)

    Z. Raida

    2006-12-01

    Full Text Available In the paper, dielectric and metallic lenses are modeled and optimized in order to enhance the gain of a horn antenna in the frequency range from 60 GHz to 100 GHz. Properties of designed lenses are compared and discussed. The structures are modeled in CST Microwave Studio and optimized by Particle Swarm Optimization (PSO in order to get required antenna parameters.

  16. Resonance Raman and surface-enhanced resonance Raman spectra of LH2 antenna complex from Rhodobacter sphaeroides and Ectothiorhodospira sp. excited in the Qx and Qy transitions.

    Science.gov (United States)

    Chumanov, G; Picorel, R; Ortiz de Zarate, I; Cotton, T M; Seibert, M

    2000-05-01

    Well-resolved vibrational spectra of LH2 complex isolated from two photosynthetic bacteria, Rhodobacter sphaeroides and Ectothiorhodospira sp., were obtained using surface-enhanced resonance Raman scattering (SERRS) exciting into the Qx and the Qy transitions of bacteriochlorophyll a. High-quality SERRS spectra in the Qy region were accessible because the strong fluorescence background was quenched near the roughened Ag surface. A comparison of the spectra obtained with 590 nm and 752 nm excitation in the mid- and low-frequency regions revealed spectral differences between the two LH2 complexes as well as between the LH2 complexes and isolated bacteriochlorophyll a. Because peripheral modes of pigments contribute mainly to the low-frequency spectral region, frequencies and intensities of many vibrational bands in this region are affected by interactions with the protein. The results demonstrate that the microenvironment surrounding the pigments within the two LH2 complexes is somewhat different, despite the fact that the complexes exhibit similar electronic absorption spectra. These differences are most probably due to specific pigment-pigment and pigment-protein interactions within the LH2 complexes, and the approach might be useful for addressing subtle static and dynamic structural variances between pigment-protein complexes from different sources or in complexes altered chemically or genetically.

  17. Three-dimensional visualization and analysis of a dual-disk resonator with dielectric misalignment and surface anomaly using edge finite elements

    Science.gov (United States)

    Villalva, Gustavo Jose

    The search for life in other planets and solar systems by scientists and engineers brings about an effort to design and develop equipment of high standards which extend the capability to listen for signals which have been traveling in space many light years. In this study the purpose was to provide a more realistic and illustrative scientific understanding of one such piece of precision equipment, the dielectric resonator, which designers seek to extend its frequency stability below 10-15. At such tolerances special cryogenic cooling procedures are required. Due to its accuracy it can be used to set short term time and frequency standards to correct the atomic clock. A theoretical means of studying this type of resonant device is necessary. One contribution made in extending the current understanding of such a device is the scientific tool developed specifically for this dissertation. It applies the Minimum Theorem from variational calculus using edge finite elements for numerical modeling. The use of quasi-linear vector basis functions allowed an implementation of Helmholtz's three-dimensional equation without a penalty term. Furthermore, the intermixing of spurious solutions with the true ones due to a nodal basis was eliminated. Calculation of the average edge electric fields was made possible by applying the Rayleigh-Ritz criterion. Model enclosure was provided by a cylindrical metal shield situated in a rectangular coordinate system. Linear, homogeneous, nonmagnetic, lossless, uniaxial, and anisotropic media were considered. Integration of NASA's Unix Lanczos eigensolver permitted the accurate estimation of the smaller eigenvalues and associated vectors for large matrices on workstations and personal computers in relatively short computational times. Calculation of the lower frequency modes demonstrated the ability to address device imperfections for two selected cases. Both were influenced by problems encountered in the use of crystals constrained by cost, or

  18. Detection of a buried object with pulse-compensated wire antennas

    NARCIS (Netherlands)

    Vossen, S.H.J.A.; Tijhuis, A.G.; Lepelaars, E.S.A.M.; Zwamborn, A.P.M.

    2003-01-01

    For the detection of a buried object we consider two straight thin-wire antennas above an interface between two homogeneous dielectric half spaces. One antenna is a transmitting wire and the other is a receiving wire. Our aim is to use this simple antenna set up for the detection of buried objects

  19. Nano Antenna Integrated Diode (Rectenna) For Infrared Energy Harvesting

    KAUST Repository

    Gadalla, Mena N.

    2013-01-01

    In this work full parametric analysis of nano antennas is presented. To begin with, optical or electronic properties of noble metals such as gold and copper were studied in details to get a clear understanding of their reaction to an incident electromagnetic wave. Complex frequency dependent dielectric functions indicated that in THz metals acts as a dielectric with significant absorption. Simultaneous optimization of the length and the bow angle of a bow-tie antenna resulted in relative electric field intensity enhancement of 8 orders of magnitude for 0.5nm gap and 4 orders of magnitude for 50nm around 28THz resonance frequency. These results are at least 2 orders of magnitude greater than the published optical antennas. Physical reasons behind field localization and intensity enhancement  are  discussed  in  details.  The  solution  of  Maxwell’s  equations  at   the  interface   between metallic nano antenna and air is also present in this piece of research. The derived dispersion relation of surface plasmons shows momentum matching at 28.3 THz between free propagating electromagnetic fields’ modes in air and localized modes at the interface. Consequently, Propagating electromagnetic waves are ensured to couple to localized surface propagating modes producing filed enhancement. The integrated matching section is theoretically proven to increase transmission to substrate to 75% (compared to 40% without it) which in turn improves the coupled power by 40 times. Nano antennas were fabricated in house using Electron beam lithography with a precise gap of 50nm. In addition, THz diode was designed, fabricated and integrated to the nano antennas to rectify the enhanced THz signal. The integration of the nano diode required a precise overlap of the two arms of the antenna in the rage of 100nm. In order to overcome two arms overlap fabrication challenges, three layer alignment technique was used to produce precise overlap.The THz rectifier was

  20. Slotted Antenna with Uniaxial Dielectric Covering

    Science.gov (United States)

    2016-07-08

    February 2017 The below identified patent application is available for licensing. Requests for information should be addressed to...therefor. CROSS REFERENCE TO OTHER PATENT APPLICATIONS [0002] None. BACKGROUND OF THE INVENTION (1) Field of the Invention [0003] The present...have been proposed in submarine applications before. For example, in U.S. Patent No. 6,127,983, Rivera and Josypenko disclose a horizontally mounted

  1. Characterization and study of dielectric and electrical properties of CaBi4Ti4O{sub 15} (CBT) added with Bi{sub 2}O{sub 3}; Caracterizacao e estudo das propriedades eletricas e dieletricas do CaBi{sub 4}Ti{sub 4}O{sub 15} (CBT) adicionado com Bi{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, D.B.; Campos Filho, M.C.; Sales, J.C.; Silva, P.M.O.; Sombra, A.S. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil)

    2011-07-01

    The ceramic perovskite CaBi{sub 4}Ti{sub 4}O{sub 15} (CBT) of space group A21am, Aurivillius family with deficiency A{sub 5}B{sub 4}O{sub 15} cation has been prepared by solid state method in a planetary ball mill of high energy. The reagents samples were ground and calcined and then added with Bi{sub 2}O{sub 3} (2% wt.) This work aims to characterize by X-ray diffraction to study the electrical properties and dielectric properties of (CBT). The x-ray diffraction revealed the formation of single orthorhombic phase. As for the dielectric properties (dielectric constant and dielectric loss) were measured at 30 deg C to 450 deg C, through which can be verified the presence of thermally activated processes. This phase has properties very relevant for possible use in capacitive devices, miniaturized filters, dielectric resonators antennas and oscillators. (author)

  2. 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...

  3. Dielectric nanoresonators for light manipulation

    Science.gov (United States)

    Yang, Zhong-Jian; Jiang, Ruibin; Zhuo, Xiaolu; Xie, Ya-Ming; Wang, Jianfang; Lin, Hai-Qing

    2017-07-01

    Nanostructures made of dielectric materials with high or moderate refractive indexes can support strong electric and magnetic resonances in the optical region. They can therefore function as nanoresonators. In addition to plasmonic metal nanostructures that have been widely investigated, dielectric nanoresonators provide a new type of building blocks for realizing powerful and versatile nanoscale light manipulation. In contrast to plasmonic metal nanostructures, nanoresonators made of appropriate dielectric materials are low-cost, earth-abundant and have very small or even negligible light energy losses. As a result, they will find potential applications in a number of photonic devices, especially those that require low energy losses. In this review, we describe the recent progress on the experimental and theoretical studies of dielectric nanoresonators. We start from the basic theory of the electromagnetic responses of dielectric nanoresonators and their fabrication methods. The optical properties of individual dielectric nanoresonators are then elaborated, followed by the coupling behaviors between dielectric nanoresonators, between dielectric nanoresonators and substrates, and between dielectric nanoresonators and plasmonic metal nanostructures. The applications of dielectric nanoresonators are further described. Finally, the challenges and opportunities in this field are discussed.

  4. Compact super-wideband optical antenna

    Science.gov (United States)

    Wang, Wen C.; Forber, Richard; Bui, Kenneth

    2009-05-01

    We present progress on advanced optical antennas, which are compact, small size-weight-power units capable to receive super wideband radiated RF signals from 30 MHz to over 3 GHz. Based on electro-optical modulation of fiber-coupled guided wave light, these dielectric E-field sensors exhibit dipole-like azimuthal omni directionality, and combine small size (channels, and high EO sensing materials. The antenna system photonic link consists of a 1550 nm PM fiber-pigtailed laser, a specialized optical modulator antenna in channel waveguide format, a wideband photoreceiver, and optical phase stabilizing components. The optical modulator antenna design employs a dielectric (no electrode) Mach-Zehnder interferometer (MZI) arranged so that sensing RF bandwidth is not limited by optical transit time effects, and MZI phase drift is bias stabilized. For a prototype optical antenna system that is < 100 in3, < 10 W, < 5 lbs, we present test data on sensitivity (< 20 mV/m-Hz1/2), RF bandwidth, and antenna directionality, and show good agreement with theoretical predictions.

  5. Band-notched spiral antenna

    Science.gov (United States)

    Jeon, Jae; Chang, John

    2018-03-13

    A band-notched spiral antenna having one or more spiral arms extending from a radially inner end to a radially outer end for transmitting or receiving electromagnetic radiation over a frequency range, and one or more resonance structures positioned adjacent one or more segments of the spiral arm associated with a notch frequency band or bands of the frequency range so as to resonate and suppress the transmission or reception of electromagnetic radiation over said notch frequency band or bands.

  6. Multiband Patch Antenna for Femtocell Application

    Directory of Open Access Journals (Sweden)

    M. R. Zaman

    2014-01-01

    Full Text Available A microstrip patch antenna for multiple LTE (long term evaluation frequency bands for femtocell application is proposed in this paper. Distributed antenna solution (DAS has been introduced in cellular network to achieve homogenous indoor coverage. Femtocell is the latest extension to these solutions. It is a smart solution to both coverage and capacity scales. Femtocell operation in LTE band is occupied by higher frequency bands. For multiband femtocell application, miniature antenna design is quite essential. The antenna proposed here is composed of basic monopole structure with two parasitic elements at both sides of the active element. A rectangular slot is introduced at the ground plane of the proposed antenna. The antenna is designed using ElnoS HK light CCL substrate material of relative permittivity of 9.4, dielectric loss-tangent of 0.003 and thickness of 3 mm. The S11 response of the antenna is shown to have a bandwidth of 1.01 GHz starting from 1.79 GHz to 2.8 GHz. The characteristics of the antenna are analysed using Ansoft HFSS software.

  7. 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.

  8. Non-foster matching of an RFID antenna

    KAUST Repository

    Mohamed Hassan Salem, Nedime Pelin

    2011-07-01

    Novel designs of radio-frequency identification (RFID) tag antennas with better matching characteristics to achieve extended range for passive tags are investigated in ultra-high frequency (UHF) band. A microstrip dipole antenna with or without an integrated negative impedance converter designed to cancel out the antenna\\'s input capacitance at resonance frequency was designed, simulated, constructed and measured for implementation in RFID applications. © 2011 IEEE.

  9. 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.

  10. Characteristics of the wire biconical antenna used for EMC measurements

    Science.gov (United States)

    Austin, Brian A.; Fourie, Andre P. C.

    1991-08-01

    The characteristics of a wire biconical antenna that determine its antenna factor were computed by using the method of moments code NEC-2. A fairly extensive validation exercise was conducted from which a suitable computer model was derived. The input impedance, gain, and radiation patterns of the antenna were computed for special cases where the biconical antenna is used above a conducting ground plane for open-field EMC (electromagnetic compatibility) testing. The effects of height above the ground plane and polarization of the antenna on these parameters were found and the antenna factor was corrected for them. The current distribution along the antenna elements was also examined, and it was found that significant pattern distortion can occur at some frequencies when a horizontal wire biconical antenna is used close to the ground. These results will allow this broadband antenna to be used with confidence in applications where previously only resonant dipoles were specified.

  11. Modified Vivaldi antenna with improved gain and phase center stability

    DEFF Research Database (Denmark)

    Zhang, Shuai

    2016-01-01

    A modified Vivaldi antenna is proposed with improved gain and phase centre stability. By applying a high permittivity dielectric substrate, the realized gain is enlarged while maintaining the compactness of the designed antenna. With a redistributed comb-shape corrugation the phase centre stabili...... of the antenna is significantly improved. The designed modified Vivaldi antenna covers the lower UWB band of 3.1-5 GHz with a realized gain higher than 10 dBi. A stable phase centre and radiation patterns over the operating band are realized....

  12. Experimental study on propagation properties of large size TEM antennas

    International Nuclear Information System (INIS)

    Zhang Guowei; Wang Haiyang; Chen Weiqing; Wang Wei; Zhu Xiangqin; Xie Linshen

    2014-01-01

    The propagation properties of large size TEM antennas were studied by experiment. The size of the TEM antennas is 60 m × 20 m × 10 m and the character Impedance is 120 Ω. A kind of dielectric foil switch is designed compactly with TEM antennas which can generate double exponential waveform with altitude of 10 kV and rise time of l.2 ns. The radiated field distribution was measured. The relationship between rise time/altitude and distance were provided, and the propagation properties of large size TEM antennas were summarized. (authors)

  13. 3D printed helical antenna with lens

    KAUST Repository

    Farooqui, Muhammad Fahad

    2016-12-19

    The gain of an antenna can be enhanced through the integration of a lens, however this technique has traditionally been restricted to planar antennas due to fabrication limitations of standard manufacturing processes. Here, with a unique combination of 3D and 2D inkjet printing of dielectric and metallic inks respectively, we demonstrate a Fresnel lens that has been monolithically integrated to a non-planar antenna (helix) for the first time. Antenna measurements show that the integration of a Fresnel lens enhances the gain of a 2-turn helix by around 4.6 dB giving a peak gain of about 12.9 dBi at 8.8 GHz.

  14. Magnetic antenna excitation of whistler modes. IV. Receiving antennas and reciprocity

    Energy Technology Data Exchange (ETDEWEB)

    Stenzel, R. L., E-mail: stenzel@physics.ucla.edu; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)

    2015-07-15

    Antenna radiation patterns are an important property of antennas. Reciprocity holds in free space and the radiation patterns for exciting and receiving antennas are the same. In anisotropic plasmas, radiation patterns are complicated by the fact that group and phase velocities differ and certain wave properties like helicity depend on the direction of wave propagation with respect to the background magnetic field B{sub 0}. Interference and wave focusing effects are different than in free space. Reciprocity does not necessarily hold in a magnetized plasma. The present work considers the properties of various magnetic antennas used for receiving whistler modes. It is based on experimental data from exciting low frequency whistler modes in a large uniform laboratory plasma. By superposition of linear waves from different antennas, the radiation patterns of antenna arrays are derived. Plane waves are generated and used to determine receiving radiation patterns of different receiving antennas. Antenna arrays have radiation patterns with narrow lobes, whose angular position can be varied by physical rotation or electronic phase shifting. Reciprocity applies to broadside antenna arrays but not to end fire arrays which can have asymmetric lobes with respect to B{sub 0}. The effect of a relative motion between an antenna and the plasma has been modeled by the propagation of a short wave packet moving along a linear antenna array. An antenna moving across B{sub 0} has a radiation pattern characterized by an oscillatory “whistler wing.” A receiving antenna in motion can detect any plane wave within the group velocity resonance cone. The radiation pattern also depends on loop size relative to the wavelength. Motional effects prevent reciprocity. The concept of the radiation pattern loses its significance for wave packets since the received signal does not only depend on the antenna but also on the properties of the wave packet. The present results are of fundamental

  15. Magnetic antenna excitation of whistler modes. IV. Receiving antennas and reciprocity

    International Nuclear Information System (INIS)

    Stenzel, R. L.; Urrutia, J. M.

    2015-01-01

    Antenna radiation patterns are an important property of antennas. Reciprocity holds in free space and the radiation patterns for exciting and receiving antennas are the same. In anisotropic plasmas, radiation patterns are complicated by the fact that group and phase velocities differ and certain wave properties like helicity depend on the direction of wave propagation with respect to the background magnetic field B 0 . Interference and wave focusing effects are different than in free space. Reciprocity does not necessarily hold in a magnetized plasma. The present work considers the properties of various magnetic antennas used for receiving whistler modes. It is based on experimental data from exciting low frequency whistler modes in a large uniform laboratory plasma. By superposition of linear waves from different antennas, the radiation patterns of antenna arrays are derived. Plane waves are generated and used to determine receiving radiation patterns of different receiving antennas. Antenna arrays have radiation patterns with narrow lobes, whose angular position can be varied by physical rotation or electronic phase shifting. Reciprocity applies to broadside antenna arrays but not to end fire arrays which can have asymmetric lobes with respect to B 0 . The effect of a relative motion between an antenna and the plasma has been modeled by the propagation of a short wave packet moving along a linear antenna array. An antenna moving across B 0 has a radiation pattern characterized by an oscillatory “whistler wing.” A receiving antenna in motion can detect any plane wave within the group velocity resonance cone. The radiation pattern also depends on loop size relative to the wavelength. Motional effects prevent reciprocity. The concept of the radiation pattern loses its significance for wave packets since the received signal does not only depend on the antenna but also on the properties of the wave packet. The present results are of fundamental interest and of

  16. Broadband standard dipole antenna for antenna calibration

    Science.gov (United States)

    Koike, Kunimasa; Sugiura, Akira; Morikawa, Takao

    1995-06-01

    Antenna calibration of EMI antennas is mostly performed by the standard antenna method at an open-field test site using a specially designed dipole antenna as a reference. In order to develop broadband standard antennas, the antenna factors of shortened dipples are theoretically investigated. First, the effects of the dipole length are analyzed using the induced emf method. Then, baluns and loads are examined to determine their influence on the antenna factors. It is found that transformer-type baluns are very effective for improving the height dependence of the antenna factors. Resistive loads are also useful for flattening the frequency dependence. Based on these studies, a specification is developed for a broadband standard antenna operating in the 30 to 150 MHz frequency range.

  17. A Dual-Band Multiple Input Multiple Output Frequency Agile Antenna for GPSL1/Wi-Fi/WLAN2400/LTE Applications

    Directory of Open Access Journals (Sweden)

    Sajid Aqeel

    2016-01-01

    Full Text Available A novel dual-band, single element multiple input multiple output (MIMO dielectric resonator antenna (DRA with a modest frequency tuning ability is presented in this communication. The proposed antenna operates at GPS L1/Bluetooth/Wi-Fi/LTE2500/WLAN2400 frequency bands. A single dielectric resonator element is fed by two coaxial probes to excite the orthogonal modes. A couple of slots are introduced on the ground plane to improve the isolation between antenna ports. The slots also serve the purpose of reconfiguration in the lower band on placement of switches at optimized locations. The measured impedance bandwidth is 5.16% (1.41–1.49 GHz in the lower band and 26% (2.2–2.85 GHz in the higher band. The lower band reconfigures with an impedance bandwidth of 6.5% (1.55–1.65 GHz when PIN diodes are switched ON. The gain, efficiency, correlation coefficient, and diversity gain of the MIMO DRA are presented with a close agreement between simulated and measured results.

  18. Scalable Notch Antenna System for Multiport Applications

    Directory of Open Access Journals (Sweden)

    Abdurrahim Toktas

    2016-01-01

    Full Text Available A novel and compact scalable antenna system is designed for multiport applications. The basic design is built on a square patch with an electrical size of 0.82λ0×0.82λ0 (at 2.4 GHz on a dielectric substrate. The design consists of four symmetrical and orthogonal triangular notches with circular feeding slots at the corners of the common patch. The 4-port antenna can be simply rearranged to 8-port and 12-port systems. The operating band of the system can be tuned by scaling (S the size of the system while fixing the thickness of the substrate. The antenna system with S: 1/1 in size of 103.5×103.5 mm2 operates at the frequency band of 2.3–3.0 GHz. By scaling the antenna with S: 1/2.3, a system of 45×45 mm2 is achieved, and thus the operating band is tuned to 4.7–6.1 GHz with the same scattering characteristic. A parametric study is also conducted to investigate the effects of changing the notch dimensions. The performance of the antenna is verified in terms of the antenna characteristics as well as diversity and multiplexing parameters. The antenna system can be tuned by scaling so that it is applicable to the multiport WLAN, WIMAX, and LTE devices with port upgradability.

  19. Power deposition profiles and Poynting vector distribution of phased antenna arrays in the ion-cyclotron resonance heating of a NET/INTOR-type tokamak

    International Nuclear Information System (INIS)

    Bhatnagar, V.P.; Koch, R.

    1986-01-01

    The heating produced by magnetosonic waves launched from phased antenna arrays in the ion-cyclotron range of frequencies is studied for a large tokamak with NET/INTOR-like parameters. The model used combines a 3-D planar, cold-plasma, antenna-plasma coupling code and a 3-D non-circular, toroidal, hot-plasma/ray-tracing code. First, the fractional power absorption of a ray during a single transit through the absorption layer is studied in a D-T plasma indicating total absorption in all INTOR cases except during the initial state characterized by low plasma temperature and density. However, in this case the single-pass wave absorption can be increased considerably by adding a few per cent of hydrogen. Further, complete power deposition profiles and Poynting vector distributions are presented for 'symmetric' and 'antisymmetric' 2x2 antenna array configurations with ksub(parallel)-shaping. Excitation of coaxial modes has, for the first time, been demonstrated explicitly by analysis of the Poynting vector distribution in real space. An antenna configuration with a π-phasing in the z-direction (such that the radiated power spectrum peaks at ksub(parallel) approx.= 5 m -1 ) and the choice of 3lambda/4 long antenna elements with 'symmetric' excitation in the y-direction, are found to produce central RF power deposition profiles in the second-harmonic and minority heating of INTOR. Finally, from a comparison of results for circular and non-circular NET/INTOR plasmas with elongation kappa=1.6, it is found that in the latter wave focusing is greatly reduced and that the power density figures are lower by approximately a factor of 1.9 for the case treated. (author)

  20. Electrically Small Magnetic Dipole Antennas With Quality Factors Approaching the Chu Lower Bound

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Breinbjerg, Olav; Yaghjian, Arthur D.

    2010-01-01

    We investigate the quality factor Q for electrically small current distributions and practical antenna designs radiating the TE10 magnetic dipole field. The current distributions and the antenna designs employ electric currents on a spherical surface enclosing a magneto-dielectric material...... numerically. It is found that for a given antenna size and permittivity there is an optimum permeability that ensures the lowest possible Q, and this optimum permeability is inversely proportional to the square of the antenna electrical radius. When the relative permittivity is equal to 1, the optimum...... permeability yields the quality factor Q that constitutes the lower bound for a magnetic dipole antenna with a magneto-dielectric core. Furthermore, the smaller the antenna the closer its quality factor Q can approach the Chu lower bound. Simulated results for the TE10-mode multiarm spherical helix antenna...

  1. Microrectenna: A Terahertz Antenna and Rectifier on a Chip

    Science.gov (United States)

    Siegel, Peter

    2007-01-01

    A microrectenna that would operate at a frequency of 2.5 THz has been designed and partially fabricated. The circuit is intended to be a prototype of an extremely compact device that could be used to convert radio-beamed power to DC to drive microdevices (see Figure 1). The microrectenna (see Figure 2) circuit consists of an antenna, a diode rectifier and a DC output port. The antenna consists of a twin slot array in a conducting ground plane (denoted the antenna ground plane) over an enclosed quarter-wavelength-thick resonant cavity (denoted the reflecting ground plane). The circuit also contains a planar high-frequency low-parasitic Schottky-barrier diode, a low-impedance microstrip transmission line, capacitors, and contact beam leads. The entire 3-D circuit is fabricated monolithically from a single GaAs wafer. The resonant cavity renders the slot radiation pattern unidirectional with a half-power beam width of about 65. A unique metal mesh on the rear of the wafer forms the backplate for the cavity but allows the GaAs to be wet etched from the rear surface of the twin slot antennas and ground plane. The beam leads protrude past the edge of the chip and are used both to mount the microrectenna and to make the DC electrical connection with external circuitry. The antenna ground plane and the components on top of it are formed on a 2- m thick GaAs membrane that is grown in the initial wafer MBE (molecular beam epitaxy) process. The side walls of the antenna cavity are not metal coated and, hence, would cause some loss of power; however, the relatively high permittivity (epsilon=13) of the GaAs keeps the cavity modes well confined, without the usual surface-wave losses associated with thick dielectric substrates. The Schottky-barrier diode has the usual submicron dimensions associated with THz operation and is formed in a mesa process above the antenna ground plane. The diode is connected at the midpoint of a microstrip transmission line, which is formed on 1- m

  2. Dielectric Wakefield Researches

    International Nuclear Information System (INIS)

    Kiselev, V.A.; Linnik, A.F.; Onishchenko, N.I.; Uskov, V.V.; Marshall, T.C.

    2006-01-01

    Excitation of wakefield in cylindrical dielectric waveguide/resonator by a sequence of relativistic electron bunches was investigated using an electron linac 'Almaz-2' (4.5 MeV, 6·10 3 bunches of duration 60 ps and charge 0.32 nC each). Energy spectrum of electrons, radial topography and longitudinal distribution of wakefield, and total energy of excited wakefield were measured by means of magnetic analyzer, high frequency probe, and a sensitive calorimeter

  3. Sensitivity of a combined gravitational antenna

    International Nuclear Information System (INIS)

    Kulagin, V.V.; Rudenko, V.N.

    1986-01-01

    A modification of a combined optico-acoustic gravitational antenna: a long-base laser interferometer, where free masses are changed by Weber resonators, is suggested. The combined gravitational antenna can possess sensitivity h min ∼ 10 -18 without deep cooling of Weber resonators and h min ∼ 10 -19 at helium temperaure of the resonators. This antenna has the following new quantities: presence of three independent responses, that permits to a considerable extent to exclude non-gravitational effects; presence of responses of two separated Weber resonators, that permits to register the wave character of gravitational perturbation by measuring phase shift between relaxation ''tails''. It means that one may with certainty register the wave structure of gravitational radiation for perturbation of metrics h, exceeding the threshold sensitivity of the known detectors by an order

  4. Resonance

    DEFF Research Database (Denmark)

    Petersen, Nils Holger

    2014-01-01

    A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice.......A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice....

  5. Compact, Frequency Reconfigurable, Printed Monopole Antenna

    Directory of Open Access Journals (Sweden)

    Ricardo Gonçalves

    2012-01-01

    Full Text Available This paper proposes a possible implementation of a compact printed monopole antenna, useful to operate in UMTS and WLAN bands. In order to accomplish that, a miniaturization technique based on the application of chip inductors is used in conjunction with frequency reconfiguration capability. The chip inductors change the impedance response of the monopole, allowing to reduce the resonant frequency. In order to be able to operate the antenna in these two different frequencies, an antenna reconfiguration technique based on PIN diodes is applied. This procedure allows the change of the active form of the antenna leading to a shift in the resonant frequency. The prototype measurements show good agreement with the simulation results.

  6. Electrically small circularly polarized spherical antenna with air core

    DEFF Research Database (Denmark)

    Kim, O. S.

    2013-01-01

    An electrically small circularly polarized self-resonant spherical antenna with air core is presented. The antenna is a modified multiarm spherical helix exciting TM10 and TE10 spherical modes with equal radiated power, and thus yielding perfect circular polarization over the entire far......-field sphere (except the polar regions, where the radiation is low). The self-resonance is achieved by exciting higher-order TM modes, which provide the necessary electric stored energy in the near-field, while contributing negligibly to the far-field radiation of the antenna. The antenna has electrical size...

  7. A New Generation of Antenna Structures Based on Novel Composite Materials

    National Research Council Canada - National Science Library

    Katehi, Linda

    1999-01-01

    ... of. In this study, we load a slot ring radiator with a finite dielectric lens, which increases the propagation constant around the antenna as well as over its aperture and therefore relaxes the size requirement...

  8. Design of a slimline directional borehole radar antenna using FDTD

    CSIR Research Space (South Africa)

    Vogt, D

    2008-06-01

    Full Text Available , dielectric. I. INTRODUCTION Borehole radar is the application of Ground Penetrating Radar (GPR) within a borehole [11]. GPR is a technique used to delineate structures and features of a subsurface. The borehole radar technique has been used successfully..., the direction of the incoming EM wave can be determined [6]. III. FILLER MATERIAL INSIDE ANTENNA ARRAY Ideally, there is no material between the antenna body and the rock surrounding it. In that case, the filler material would be matched to the dielectric...

  9. 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...

  10. Plasma antennas: dynamically configurable antennas for communications

    International Nuclear Information System (INIS)

    Borg, G.; Harris, J.

    1999-01-01

    In recent years, the rapid growth in both communications and radar systems has led to a concomitant growth in the possible applications and requirements of antennas. These new requirements include compactness and conformality, rapid reconfigurability for directionality and frequency agility. For military applications, antennas should also allow low absolute or out-of-band radar cross-section and facilitate low probability of intercept communications. Investigations have recently begun worldwide on the use of ionised gases or plasmas as the conducting medium in antennas that could satisfy these requirements. Such plasma antennas may even offer a viable alternative to metal in existing applications when overall technical requirements are considered. A recent patent for ground penetrating radar claims the invention of a plasma antenna for the transmission of pulses shorter than 100 ns in which it is claimed that current ringing is avoided and signal processing simplified compared with a metal antenna. A recent US ONR tender has been issued for the design and construction of a compact and rapidly reconfigurable antenna for dynamic signal reception over the frequency range 1 - 45 GHz based on plasma antennas. Recent basic physics experiments at ANU have demonstrated that plasma antennas can attain adequate efficiency, predictable radiation patterns and low base-band noise for HF and VHF communications. In this paper we describe the theory of the low frequency plasma antenna and present a few experimental results

  11. Experimental measurements of the ion cyclotron antennas' coupling and rf characteristics

    International Nuclear Information System (INIS)

    Hoffman, D.J.; Baity, F.W.; Becraft, W.R.; Caughman, J.B.O.; Owens, T.L.

    1985-01-01

    The rf coupling capabilities and characteristics of various antennas have been measured. The tested antenna configurations include the simple loop antenna operated at resonant lengths as used on Alcator-C, the cavity antenna proposed for Doublet III-D and the resonant double loop, asymmetric resonant double loop, and U-slot antennas. Models of the voltage, magnetic fields outside the structure, and current have been correlated with the measurements made on these antennas. From these measurements and from typical observations of ICRH coupling in tokamaks, we are studying power and frequency limitations on each antenna and the causes of the limitations. A comparison of the technology, performance, and power limitations of each type of antenna is presented

  12. RF cavity using liquid dielectric for tuning and cooling

    Science.gov (United States)

    Popovic, Milorad [Warrenville, IL; Johnson, Rolland P [Newport News, VA

    2012-04-17

    A system for accelerating particles includes an RF cavity that contains a ferrite core and a liquid dielectric. Characteristics of the ferrite core and the liquid dielectric, among other factors, determine the resonant frequency of the RF cavity. The liquid dielectric is circulated to cool the ferrite core during the operation of the system.

  13. RFID on the Road-Some Considerations About Passive Tag Antennas

    DEFF Research Database (Denmark)

    Franek, Ondrej; Kyritsi, Persefoni; Pedersen, Gert Frølund

    2011-01-01

    This paper presents an investigation of tag antenna performance in the scenario of a passive RFID tag placed on an asphalt road and inquired by readers in vehicles. Three types of antennas were chosen and their properties were studied for various dielectric properties of the asphalt paving. Water...

  14. Evaluation of detectable angle of mid-infrared slot antennas

    Science.gov (United States)

    Obara, R.; Horikawa, J.; Shimakage, H.; Kawakami, A.

    2017-07-01

    For evaluations of a mid-infrared (MIR) detectors with antenna, we constructed an angular dependence measurement system of the antenna properties. The fabricated MIR detector consisted of twin slot antennas and a bolometer. The area of the slot antennas was designed to be 2.6 × 0.2 μm2 as to resonate at 61 THz, and they were located parallel and separated 1.6 μm each other. The bolometer was fabricated using by a 7.0-nm thick NbN thin film, and located at the center of the twin antennas. We measured polarization angle dependence and directivity, and showed that the MIR antennas have polarization dependence and directivity like radiofrequency antennas.

  15. Resonances

    DEFF Research Database (Denmark)

    an impetus or drive to that account: change, innovation, rupture, or discontinuity. Resonances: Historical Essays on Continuity and Change explores the historiographical question of the modes of interrelation between these motifs in historical narratives. The essays in the collection attempt to realize...

  16. A New Metasurface Superstrate Structure for Antenna Performance Enhancement.

    Science.gov (United States)

    Islam, Mohammad Tariqul; Ullah, Mohammad Habib; Singh, Mandeep Jit; Faruque, Mohammad Rashed Iqbal

    2013-07-31

    A new metasurface superstrate structure (MSS)-loaded dual band microstrip line-fed small patch antenna is presented in this paper. The proposed antenna was designed on a ceramic-filled bioplastic sandwich substrate with a high dielectric constant. The proposed 7 × 6 element, square-shaped, single-sided MSS significantly improved the bandwidth and gain of the proposed antenna. The proposed MSS incorporated a slotted patch antenna that effectively increased the measured operating bandwidth from 13.3% to 18.8% and from 14.8% to 23.2% in the lower and upper bands, respectively. Moreover, the average gain of the proposed MSS-based antenna was enhanced from 2.12 dBi to 3.02 dBi in the lower band and from 4.10 dBi to 5.28 dBi in the upper band compared to the patch antenna alone. In addition to the bandwidth and gain improvements, more directive radiation characteristics were also observed from the MSS antenna compared to the patch itself. The effects of the MSS elements and the ground plane length on the reflection coefficient of the antenna were analyzed and optimized. The overall performance makes the proposed antenna appropriate for RFID and WLAN applications.

  17. Radio frequency and capacitive sensors for dielectric characterization of low-conductivity media

    Science.gov (United States)

    Sheldon, Robert T.

    Low-conductivity media are found in a vast number of applications, for example as electrical insulation or as the matrix polymer in high strength-to-weight ratio structural composites. In some applications, these materials are subjected to extreme environmental, thermal, and mechanical conditions that can affect the material's desired performance. In a more general sense, a medium may be comprised of one or more layers with unknown material properties that may affect the desired performance of the entire structure. It is often, therefore, of great import to be able to characterize the material properties of these media for the purpose of estimating their future performance in a certain application. Low-conductivity media, or dielectrics, are poor electrical conductors and permit electromagnetic waves and static electric fields to pass through with minimal attenuation. The amount of electrical energy that may be stored (and lost) in these fields depends directly upon the material property, permittivity, which is generally complex, frequency-dependent and has a measurable effect on sensors designed to characterize dielectric media. In this work, two different types of dielectric sensors: radio frequency resonant antennas and lower-frequency (work, the capability of characterizing multilayer dielectric structures is studied using a patch antenna, a type of antenna that is primarily designed for data communications in the microwave bands but has application in the field of nondestructive evaluation as well. Each configuration of a patch antenna has a single lowest resonant (dominant mode) frequency that is dependent upon the antenna's substrate material and geometry as well as the permittivity and geometry of exterior materials. Here, an extant forward model is validated using well-characterized microwave samples and a new method of resonant frequency and quality factor determination from measured data is presented. Excellent agreement between calculated and measured

  18. Printing of Wearable Antenna on Textile

    Directory of Open Access Journals (Sweden)

    Khirotdin Rd. Khairilhijra

    2018-01-01

    Full Text Available A wearable antenna which is meant to be a part of the clothing used for communication purposes includes tracking, navigation and mobile computing has been seen in demand due to the recent miniaturization of wireless devices. Printing of conductive ink provides flexibility properties on electronics thus allowing it to be used on conformal surfaces. However, the current printing techniques mostly suffer from ink incompatibility and limited of substrates to be printed with. Hence, this paper intend to discloses the printing of wearable antenna using alternative technique via syringe-based deposition system with conductive ink on textile. A validation between simulation and measurement of return loss, (S11 and radiation pattern of the antenna printed is also performed. It was found that a functional antenna is successfully printed on textile since the performances obtained are as expected. The antenna resonated at a minimum resonant frequency of 1.82 GHz which the S11 gathered at-18.90 dB. The radiation pattern for both simulation and measurement is as predicted since both have a larger magnitude of the main lobe than the side lobe. The magnitude of the main lobe from measurement was observed to be 8.83 dB higher than the magnitude of the main lobe of the simulation which is only 3.77 dB. It is proven that the syringe-based deposition system is capable of printing functional antenna on textile.

  19. Microwave dielectric properties of (1 − x)Mg0.95Zn0.05TiO3–(x)Ca0.6La0.8/3TiO3 ceramic composites

    International Nuclear Information System (INIS)

    Rajput, Shailendra Singh; Keshri, Sunita; Gupta, Vibha Rani

    2013-01-01

    Highlights: ► This report presents the microwave dielectric properties of (1 − x)MZT–(x)CLT samples. ► The 0.79MZT-0.21CLT composite sample shows a nearly zero τ f ∼ −0.8 ppm/°C. ► A dielectric resonator antenna has been fabricated using 0.79MZT-0.21CLT sample. ► The probe fed DRA provides higher gain as compared to the microstrip line fed DRA. -- Abstract: In this paper the structural and microwave dielectric properties of the (1 − x)(Mg 0.95 Zn 0.05 )TiO 3 –(x)(Ca 0.6 La 0.8/3 )TiO 3 ceramic composites have been investigated with the variation of x as well as sintering temperature. The grown samples have been characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectroscopy analysis. The Rietveld analysis of the XRD data has been carried out for structure refinement of the phases. The relative permittivity (∊ r ), quality factor (Q) and temperature coefficient of resonant frequency τ f of the grown samples have been thoroughly studied. Out of all samples of this series, the sample with x = 0.21 shows excellent dielectric properties with ∊ r ∼26.26, Q × f ∼ 60,738 GHz (at 6.44 GHz) and a nearly zero τ f ∼ −0.8 ppm/°C. Two types of dielectric resonator antennas with different feeding mechanisms have been fabricated using this sample to study their performance. The experimental results have been compared with the simulated results obtained using Ansoft High Frequency Structure Simulator software

  20. A Single Atom Antenna

    International Nuclear Information System (INIS)

    Trinter, Florian; Williams, Joshua B; Weller, Miriam; Waitz, Markus; Pitzer, Martin; Voigtsberger, Jörg; Schober, Carl; Kastirke, Gregor; Müller, Christian; Goihl, Christoph; Burzynski, Phillip; Wiegandt, Florian; Wallauer, Robert; Kalinin, Anton; Schmidt, Lothar Ph H; Schöffler, Markus S; Jahnke, Till; Dörner, Reinhard; Chiang, Ying-Chih; Gokhberg, Kirill

    2015-01-01

    Here we demonstrate the smallest possible implementation of an antenna-receiver complex which consists of a single (helium) atom acting as the antenna and a second (neon) atom acting as a receiver. (paper)

  1. Antenna Pattern Range (APR)

    Data.gov (United States)

    Federal Laboratory Consortium — TheAntenna Pattern Range (APR)features a non-metallic arch with a trolley to move the transmit antenna from the horizon to zenith. At the center of the ground plane,...

  2. Equipment: Antenna systems

    Science.gov (United States)

    Petrie, L. E.

    1986-03-01

    Some antenna fundamentals as well as definitions of the principal terms used in antenna engineering are described. Methods are presented for determining the desired antenna radiation patterns for HF communication circuit or service area. Sources for obtaining or computing radiation pattern information are outlined. Comparisons are presented between the measured and computed radiation patterns. The effect of the properties of the ground on the antenna gain and the pattern are illustrated for several types of antennas. Numerous examples are given of the radiation patterns for typical antennas used on short, intermediate and long distance circuits for both mobile and fixed service operations. The application of adaptive antenna arrays and active antennas in modern HF communication systems are briefly reviewed.

  3. Hybrid Methods in Designing Sierpinski Gasket Antennas

    Directory of Open Access Journals (Sweden)

    Mudrik Alaydrus

    2010-12-01

    Full Text Available Sierpinki gasket antennas as example of fractal antennas show multiband characteristics. The computer simulation of Sierpinksi gasket monopole with finite ground needs prohibitively large computer memory and more computational time. Hybrid methods consist of surface integral equation method and physical optics or uniform geometrical theory of diffraction should alleviate this computational burdens. The so-called full hybridization of the different methods with modifying the incoming electromagnetic waves in case of hybrid method surface integral equation method and physical optics and modification of the Greens function for hybrid method surface integral equation method and uniform geometrical theory of diffraction plays the central role in the observation. Comparison between results of different methods are given and also measurements of three Sierpinksi gasket antennas. The multiband characteristics of the antennas still can be seen with some reduction and enhancement of resonances.

  4. Heating profiles on ICRF antenna Faraday shields

    International Nuclear Information System (INIS)

    Taylor, D.J.; Baity, F.W.; Hahs, C.L.; Riemer, B.W.; Ryan, P.M.; Williamson, D.E.

    1991-01-01

    A conceptual design for an uncooled Faraday shield for the BPX ion cyclotron resonance heating (ICRH) antenna, which should withstand the proposed long-pulse operation, has been completed. A high-heat-flux, uncooled Faraday shield has also been designed for the fast-wave current drive (FWCD) antenna on D3-D. For both components, the improved understanding of the heating profiles made it possible to design for heat fluxes that would otherwise have been too close to mechanically established limits. The analytical effort is described in detail, with emphasis on the design work for the BPX ICRH antenna conceptual design and for the replacement Faraday shield for the D3-D FWCD antenna. Results of analyses are shown, and configuration issues involved in component modeling are discussed. 3 refs., 6 figs., 2 tabs

  5. Optical antennas for far and near field metrology

    NARCIS (Netherlands)

    Silvestri, F.; Bernal Arango, F.; Vendel, K.J.A.; Gerini, G.; Bäumer, S.M.B.; Koenderink, A.F.

    2016-01-01

    This paper presents the use of optical antennas in metrology scenarios. Two design concepts are presented: dielectric nanoresonator arrays and plasmonic nanoantennas arrays. The first ones are able to focus an incident light beam at an arbitrary focal plane. The nanoantennas arrays can be employed

  6. Multi-Band Cable Antenna with Irregular Reactive Loading

    Science.gov (United States)

    2014-11-04

    antenna 10 consists of an insulated solid conductor 12 of radius a. Preferably, this element is made from copper ; however, any highly conductive metal...Docket No. 300035 5 of 12 improved flotation . A low dielectric constant is essential for optimal RF performance. Reactive elements (not shown, see

  7. Transformation from a Single Antenna to a Series Array Using Push/Pull Origami

    Directory of Open Access Journals (Sweden)

    Syed Imran Hussain Shah

    2017-08-01

    Full Text Available We propose a push/pull origami antenna, transformable between a single antenna element and a three-element array. In limited space, the proposed origami antenna can work as a single antenna. When the space is not limited and a higher gain is required, the proposed origami antenna can be transformed to a series antenna array by pulling the frame. In order to push the antenna array back to a single antenna, the frame for each antenna element size must be different. The frame and supporting dielectric materials are built using a three-dimensional (3D printer. The conductive patterns are inkjet-printed on paper. Thus, the proposed origami antenna is built using hybrid printing technology. The 10-dB impedance bandwidth is 2.5–2.65 GHz and 2.48–2.62 GHz for the single-antenna and array mode, respectively, and the peak gains in the single-antenna and array mode are 5.8 dBi and 7.6 dBi, respectively. The proposed antenna can be used for wireless remote-sensing applications.

  8. Transformation from a Single Antenna to a Series Array Using Push/Pull Origami.

    Science.gov (United States)

    Shah, Syed Imran Hussain; Lim, Sungjoon

    2017-08-26

    We propose a push/pull origami antenna, transformable between a single antenna element and a three-element array. In limited space, the proposed origami antenna can work as a single antenna. When the space is not limited and a higher gain is required, the proposed origami antenna can be transformed to a series antenna array by pulling the frame. In order to push the antenna array back to a single antenna, the frame for each antenna element size must be different. The frame and supporting dielectric materials are built using a three-dimensional (3D) printer. The conductive patterns are inkjet-printed on paper. Thus, the proposed origami antenna is built using hybrid printing technology. The 10-dB impedance bandwidth is 2.5-2.65 GHz and 2.48-2.62 GHz for the single-antenna and array mode, respectively, and the peak gains in the single-antenna and array mode are 5.8 dBi and 7.6 dBi, respectively. The proposed antenna can be used for wireless remote-sensing applications.

  9. Switchable Phased Antenna Array with Passive Elements for 5G Mobile Terminals

    DEFF Research Database (Denmark)

    Syrytsin, Igor A.; Zhang, Shuai; Pedersen, Gert F.

    2017-01-01

    In this paper, a reconfigurable phased antenna array system is constructed for the mobile terminals in the context of 5G communication system. The proposed antenna system operates at the resonance frequency of 28 GHz. The reconfigurability of the antenna element is achieved by using a passive slot...

  10. Novel Wideband Metallic Patch Antennas with Low Profile

    Directory of Open Access Journals (Sweden)

    Zhong-Xiang Zhang

    2017-01-01

    Full Text Available Two planar metallic patch (MP antennas with low profiles are investigated and compared in this paper. The MP of each antenna consists of metallic patch cells and it is centrally fed by a rectangular slot. Two modes with close resonance frequencies are excited, providing a quite wide bandwidth. The antenna principle is explained clearly through a parametric study. Simulated and measured results show that the MP antennas with profile of 0.06λ0 can obtain a 10 dB impedance bandwidth of ~32% and an average gain of ~10 dBi.

  11. Dielectric characterization of low-loss calcium strontium titanate fibers produced by laser floating zone technique for wireless communication

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, F. [Department of Physics and I3N, University of Aveiro, 3810-193, Aveiro (Portugal); Polytechnic Institute of Coimbra, 3000-271, Coimbra (Portugal); Valente, M.A.; Costa, L.C.; Costa, F.M. [Department of Physics and I3N, University of Aveiro, 3810-193, Aveiro (Portugal)

    2014-09-15

    Wireless communication technology assisted to a huge development during the last two decades, responding to the growing demand for small size and low weight devices such as cell phones and global positioning systems. The need for miniaturization and higher autonomy resulted in the development of new dielectric oxide ceramics with very specific properties, to be applied as dielectric resonators in filters, oscillators, and antennas. Some crucial properties as a high quality factor, high dielectric constant, and near zero temperature coefficient of resonant frequency must be considered during the selection of the appropriate materials. The present work deals with the preparation of calcium titanate (CaTiO{sub 3}), strontium titanate (SrTiO{sub 3}), and calcium strontium titanate (Ca{sub x}Sr{sub 1-x}TiO{sub 3}) fibers produced by laser floating zone (LFZ) technique. Our results show that fibers grown at lower pulling rates exhibit higher ε', for all the studied frequency range, including the microwave region. Moreover, the quality factor is always high envisaging the possibility to include these materials in future wireless device applications. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Dielectric characterization of low-loss calcium strontium titanate fibers produced by laser floating zone technique for wireless communication

    International Nuclear Information System (INIS)

    Amaral, F.; Valente, M.A.; Costa, L.C.; Costa, F.M.

    2014-01-01

    Wireless communication technology assisted to a huge development during the last two decades, responding to the growing demand for small size and low weight devices such as cell phones and global positioning systems. The need for miniaturization and higher autonomy resulted in the development of new dielectric oxide ceramics with very specific properties, to be applied as dielectric resonators in filters, oscillators, and antennas. Some crucial properties as a high quality factor, high dielectric constant, and near zero temperature coefficient of resonant frequency must be considered during the selection of the appropriate materials. The present work deals with the preparation of calcium titanate (CaTiO 3 ), strontium titanate (SrTiO 3 ), and calcium strontium titanate (Ca x Sr 1-x TiO 3 ) fibers produced by laser floating zone (LFZ) technique. Our results show that fibers grown at lower pulling rates exhibit higher ε', for all the studied frequency range, including the microwave region. Moreover, the quality factor is always high envisaging the possibility to include these materials in future wireless device applications. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. A miniaturized micro strip antenna based on sinusoidal patch geometry for implantable biomedical applications

    Science.gov (United States)

    Ibrahim, Omar A.; Elwi, Taha A.; Islam, Naz E.

    2012-11-01

    A miniaturized microstrip antenna is analyzed for implantable biomedical applications. The antenna is designed using two different commercial software packages, CST Microwave Studio and HFSS, to validate the results. The proposed design operates in the WMTS frequency band. The antenna performance is tested inside the human body, Hugo model. The antenna design is readjusted to get the desired resonant frequency. The resonant frequency, bandwidth, gain, and radiation pattern of the proposed antenna are provided in this paper. Furthermore, the effect of losses inside human body due to the fat layer is recognized.

  14. Novel wideband MIMO antennas that can cover the whole LTE spectrum in handsets and portable computers.

    Science.gov (United States)

    Sanad, Mohamed; Hassan, Noha

    2014-01-01

    A dual resonant antenna configuration is developed for multistandard multifunction mobile handsets and portable computers. Only two wideband resonant antennas can cover most of the LTE spectrums in portable communication equipment. The bandwidth that can be covered by each antenna exceeds 70% without using any matching or tuning circuits, with efficiencies that reach 80%. Thus, a dual configuration of them is capable of covering up to 39 LTE (4G) bands besides the existing 2G and 3G bands. 2×2 MIMO configurations have been also developed for the two wideband antennas with a maximum isolation and a minimum correlation coefficient between the primary and the diversity antennas.

  15. Novel Wideband MIMO Antennas That Can Cover the Whole LTE Spectrum in Handsets and Portable Computers

    Directory of Open Access Journals (Sweden)

    Mohamed Sanad

    2014-01-01

    Full Text Available A dual resonant antenna configuration is developed for multistandard multifunction mobile handsets and portable computers. Only two wideband resonant antennas can cover most of the LTE spectrums in portable communication equipment. The bandwidth that can be covered by each antenna exceeds 70% without using any matching or tuning circuits, with efficiencies that reach 80%. Thus, a dual configuration of them is capable of covering up to 39 LTE (4G bands besides the existing 2G and 3G bands. 2×2 MIMO configurations have been also developed for the two wideband antennas with a maximum isolation and a minimum correlation coefficient between the primary and the diversity antennas.

  16. Frequency-Tunable and Pattern Diversity Antennas for Cognitive Radio Applications

    Directory of Open Access Journals (Sweden)

    A. H. Ramadan

    2014-01-01

    Full Text Available Frequency-tunable microstrip antennas, for cognitive radio applications, are proposed herein. The approach is based on tuning the operating frequency of a bandpass filter that is incorporated into a wideband antenna. The integration of an open loop resonator- (OLR- based adjustable bandpass filter into a wideband antenna to transform it into a tunable filter-antenna is presented. The same technique is employed to design a cognitive radio pattern diversity tunable filter-antenna. A good agreement between the simulated and measured results for the fabricated prototypes is obtained. The radiation characteristics of each designed tunable filter-antenna are included herein.

  17. Multilayer Strip Dipole Antenna Using Stacking Technique and Its Application for Curved Surface

    Directory of Open Access Journals (Sweden)

    Charinsak Saetiaw

    2013-01-01

    Full Text Available This paper presents the design of multilayer strip dipole antenna by stacking a flexible copper-clad laminate utilized for curved surface on the cylindrical objects. The designed antenna will reduce the effects of curving based on relative lengths that are changed in each stacking flexible copper-clad laminate layer. Curving is different from each layer of the antenna, so the resonance frequency that resulted from an extended antenna provides better frequency response stability compared to modern antenna when it is curved or attached to cylindrical objects. The frequency of multilayer antenna is designed at 920 MHz for UHF RFID applications.

  18. Topology Optimization of Sub-Wavelength Antennas

    DEFF Research Database (Denmark)

    Erentok, Aycan; Sigmund, Ole

    2011-01-01

    We propose a topology optimization strategy for the systematic design of a three-dimensional (3D), conductor-based sub-wavelength antenna. The post-processed finite-element (FE) models of the optimized structure are shown to be self-resonant, efficient and exhibit distorted omnidirectional...

  19. Microwave Correlation Measurement Crossed-pair Antennas ...

    African Journals Online (AJOL)

    We propose here new processes, an add and square correlation radiometer and the non-resonant perturbation, which thoroughly investigated for different muscle phantom materials to define the optimum penetration depth of the electromagnetic field at fixed distance between the antennas. Keywords: Microwave correlation ...

  20. Single-pulse terahertz coherent control of spin resonance in the canted antiferromagnet YFeO3, mediated by dielectric anisotropy

    DEFF Research Database (Denmark)

    Jin, Zuanming; Mics, Zoltán; Ma, Guohong

    2013-01-01

    We report on the coherent control of terahertz (THz) spin waves in a canted antiferromagnet yttrium orthoferrite, YFeO3, associated with a quasiferromagnetic (quasi-FM) spin resonance at a frequency of 0.3 THz, using a single-incident THz pulse. The spin resonance is excited impulsively by the ma...... polarization of the THz oscillation at the spin resonance frequency, suggests a key role of magnon–phonon coupling in spin-wave energy dissipation....

  1. Radiation Pattern Measurement of a Low-Profile Wearable Antenna Using an Optical Fibre and a Solid Anthropomorphic Phantom

    Directory of Open Access Journals (Sweden)

    Tian Hong Loh

    2014-08-01

    Full Text Available This paper presents a study into radiation pattern measurements of an electrically small dielectric resonator antenna (DRA operating between 2.4 and 2.5 GHz in the industrial, scientific and medical (ISM radio band for body-centric wireless communication applications. To eliminate the distortion of the radiation pattern associated with the unwanted radiation from a metallic coaxial cable feeding the antenna we have replaced it with a fibre optic feed and an electro-optical (EO transducer. The optical signal is then converted back to RF using an Opto-Electric Field Sensor (OEFS system. To ensure traceable measurements of the radiation pattern performance of the wearable antenna a generic head and torso solid anthropomorphic phantom model has been employed. Furthermore, to illustrate the benefits of the method, numerical simulations of the co-polar and cross-polar H-plane radiation patterns at 2.4, 2.45, and 2.5 GHz are compared with the measured results obtained using: (i an optical fibre; and (ii a metallic coaxial cable.

  2. Antenna theory: Analysis and design

    Science.gov (United States)

    Balanis, C. A.

    The book's main objective is to introduce the fundamental principles of antenna theory and to apply them to the analysis, design, and measurements of antennas. In a description of antennas, the radiation mechanism is discussed along with the current distribution on a thin wire. Fundamental parameters of antennas are examined, taking into account the radiation pattern, radiation power density, radiation intensity, directivity, numerical techniques, gain, antenna efficiency, half-power beamwidth, beam efficiency, bandwidth, polarization, input impedance, and antenna temperature. Attention is given to radiation integrals and auxiliary potential functions, linear wire antennas, loop antennas, linear and circular arrays, self- and mutual impedances of linear elements and arrays, broadband dipoles and matching techniques, traveling wave and broadband antennas, frequency independent antennas and antenna miniaturization, the geometrical theory of diffraction, horns, reflectors and lens antennas, antenna synthesis and continuous sources, and antenna measurements.

  3. Antenna Controller Replacement Software

    Science.gov (United States)

    Chao, Roger Y.; Morgan, Scott C.; Strain, Martha M.; Rockwell, Stephen T.; Shimizu, Kenneth J.; Tehrani, Barzia J.; Kwok, Jaclyn H.; Tuazon-Wong, Michelle; Valtier, Henry; Nalbandi, Reza; hide

    2010-01-01

    The Antenna Controller Replacement (ACR) software accurately points and monitors the Deep Space Network (DSN) 70-m and 34-m high-efficiency (HEF) ground-based antennas that are used to track primarily spacecraft and, periodically, celestial targets. To track a spacecraft, or other targets, the antenna must be accurately pointed at the spacecraft, which can be very far away with very weak signals. ACR s conical scanning capability collects the signal in a circular pattern around the target, calculates the location of the strongest signal, and adjusts the antenna pointing to point directly at the spacecraft. A real-time, closed-loop servo control algorithm performed every 0.02 second allows accurate positioning of the antenna in order to track these distant spacecraft. Additionally, this advanced servo control algorithm provides better antenna pointing performance in windy conditions. The ACR software provides high-level commands that provide a very easy user interface for the DSN operator. The operator only needs to enter two commands to start the antenna and subreflector, and Master Equatorial tracking. The most accurate antenna pointing is accomplished by aligning the antenna to the Master Equatorial, which because of its small size and sheltered location, has the most stable pointing. The antenna has hundreds of digital and analog monitor points. The ACR software provides compact displays to summarize the status of the antenna, subreflector, and the Master Equatorial. The ACR software has two major functions. First, it performs all of the steps required to accurately point the antenna (and subreflector and Master Equatorial) at the spacecraft (or celestial target). This involves controlling the antenna/ subreflector/Master-Equatorial hardware, initiating and monitoring the correct sequence of operations, calculating the position of the spacecraft relative to the antenna, executing the real-time servo control algorithm to maintain the correct position, and

  4. A Compact Flexible and Frequency Reconfigurable Antenna for Quintuple Applications

    Directory of Open Access Journals (Sweden)

    M. U. Hassan

    2017-09-01

    Full Text Available A novel, compact coplanar waveguide fed flexible antenna is presented. The proposed design uses flexible Rogers RT/duroid 5880 (0.508mm thickness as a substrate with small size of 30×28.4 mm^2. Two switches are integrated on the antenna surface to change the current distribution which consequently changes the resonance frequency under different conditions of switches, thereby making it a frequency reconfigurable antenna. The antenna design is simulated on CST®MWS®. The proposed antenna exhibits VSWR less than 2 and appreciable radiation patterns with positive gain over desired frequency bands. Good agreement exists between simulated and measured results. On the basis of results, the proposed antenna is envisioned to be deployed for the following applications; aeronautical radio navigation [4.3 GHz], AMT fixed services [4.5 GHz], WLAN [5.2 GHz], Unlicensed WiMAX [5.8 GHz] and X-band [7.5 GHz].

  5. Radiation characteristics of input power from surface wave sustained plasma antenna

    Energy Technology Data Exchange (ETDEWEB)

    Naito, T., E-mail: Naito.Teruki@bc.MitsubishiElectric.co.jp [Advanced Technology R& D Center, Mitsubishi Electric Corporation, Amagasaki, Hyogo 661-8661 (Japan); Yamaura, S. [Information Technology R& D Center, Mitsubishi Electric Corporation, Kamakura, Kanagawa 247-8501 (Japan); Fukuma, Y. [Communication System Center, Mitsubishi Electric Corporation, Amagasaki, Hyogo 661-8661 (Japan); Sakai, O. [Department of Electronic System Engineering, The University of Shiga Prefecture, Hikone, Shiga 522-8533 (Japan)

    2016-09-15

    This paper reports radiation characteristics of input power from a surface wave sustained plasma antenna investigated theoretically and experimentally, especially focusing on the power consumption balance between the plasma generation and the radiation. The plasma antenna is a dielectric tube filled with argon and small amount of mercury, and the structure is a basic quarter wavelength monopole antenna at 2.45 GHz. Microwave power at 2.45 GHz is supplied to the plasma antenna. The input power is partially consumed to sustain the plasma, and the remaining part is radiated as a signal. The relationship between the antenna gain and the input power is obtained by an analytical derivation and numerical simulations. As a result, the antenna gain is kept at low values, and most of the input power is consumed to increase the plasma volume until the tube is filled with the plasma whose electron density is higher than the critical electron density required for sustaining the surface wave. On the other hand, the input power is consumed to increase the electron density after the tube is fully filled with the plasma, and the antenna gain increases with increasing the electron density. The dependence of the antenna gain on the electron density is the same as that of a plasma antenna sustained by a DC glow discharge. These results are confirmed by experimental results of the antenna gain and radiation patterns. The antenna gain of the plasma is a few dB smaller than that of the identical metal antenna. The antenna gain of the plasma antenna is sufficient for the wireless communication, although it is difficult to substitute the plasma antenna for metal antennas completely. The plasma antenna is suitable for applications having high affinity with the plasma characteristics such as low interference and dynamic controllability.

  6. Radiation characteristics of input power from surface wave sustained plasma antenna

    International Nuclear Information System (INIS)

    Naito, T.; Yamaura, S.; Fukuma, Y.; Sakai, O.

    2016-01-01

    This paper reports radiation characteristics of input power from a surface wave sustained plasma antenna investigated theoretically and experimentally, especially focusing on the power consumption balance between the plasma generation and the radiation. The plasma antenna is a dielectric tube filled with argon and small amount of mercury, and the structure is a basic quarter wavelength monopole antenna at 2.45 GHz. Microwave power at 2.45 GHz is supplied to the plasma antenna. The input power is partially consumed to sustain the plasma, and the remaining part is radiated as a signal. The relationship between the antenna gain and the input power is obtained by an analytical derivation and numerical simulations. As a result, the antenna gain is kept at low values, and most of the input power is consumed to increase the plasma volume until the tube is filled with the plasma whose electron density is higher than the critical electron density required for sustaining the surface wave. On the other hand, the input power is consumed to increase the electron density after the tube is fully filled with the plasma, and the antenna gain increases with increasing the electron density. The dependence of the antenna gain on the electron density is the same as that of a plasma antenna sustained by a DC glow discharge. These results are confirmed by experimental results of the antenna gain and radiation patterns. The antenna gain of the plasma is a few dB smaller than that of the identical metal antenna. The antenna gain of the plasma antenna is sufficient for the wireless communication, although it is difficult to substitute the plasma antenna for metal antennas completely. The plasma antenna is suitable for applications having high affinity with the plasma characteristics such as low interference and dynamic controllability.

  7. Optimization of silver-dielectric-silver nanoshell for sensing applications

    International Nuclear Information System (INIS)

    Shirzaditabar, Farzad; Saliminasab, Maryam

    2013-01-01

    In this paper, resonance light scattering (RLS) properties of a silver-dielectric-silver nanoshell, based on quasi-static approach and plasmon hybridization theory, are investigated. Scattering spectrum of silver-dielectric-silver nanoshell has two intense and clearly separated RLS peaks and provides a potential for biosensing based on surface plasmon resonance and surface-enhanced Raman scattering. The two RLS peaks in silver-dielectric-silver nanoshell are optimized by tuning the geometrical dimensions. In addition, the optimal geometry is discussed to obtain the high sensitivity of silver-dielectric-silver nanoshell. As the silver core radius increases, the sensitivity of silver-dielectric-silver nanoshell decreases whereas increasing the middle dielectric thickness increases the sensitivity of silver-dielectric-silver nanoshell

  8. Investigating antennas as ignition aid for automotive HID lamps

    International Nuclear Information System (INIS)

    Bergner, A; Engelhardt, M; Bienholz, S; Ruhrmann, C; Hoebing, T; Groeger, S; Mentel, J; Awakowicz, P

    2015-01-01

    This paper considers the ignition of mercury-free high-intensity discharge (HID) lamps for car headlights. Due to safety reasons, these lamps need to have a fast run-up phase which is ensured, amongst other things, by a high Xe pressure of roughly 15 bar (cold) in the discharge vessel. The high Xe pressure causes an increased ignition voltage compared with former mercury-containing automotive HID lamps or low-pressure lamps used for general-lighting applications. The increase in ignition voltage can be limited if the electric field in front of the electrodes is raised by an uplifting of the electrical conductivity along the outer wall of the inner bulb either by a conductive layer on its surface or by a dielectric barrier discharge (DBD) within the outer bulb. This paper considers on the one hand conventional antennas deposited by physical vapour deposition (PVD) and on the other hand a combination of these antennas with a DBD within the outer-bulb operated in 100 mbar Ar as ignition aids. In both cases the antenna potential and antenna width are varied. Additionally, the effects of antenna thickness and antenna material are investigated. The ignition voltage, ignition current and light emission during ignition are measured on a nanosecond timescale. Furthermore, for the very first time, the ignition process is recorded in four consecutive intensified charge-coupled device images using a high-speed camera system with a time resolution in the range of nanoseconds. It was found that antennas strongly reduce the ignition voltage of automotive HID lamps. Active antennas reduce the ignition voltage significantly more than passive antennas, proportional to the conductance of the antenna. Combining conventional antennas with an outer-bulb discharge reduces the ignition voltage from 19 kV without any ignition aid to the intrinsic ignition voltage of the lamp below 10 kV, in the best case. (paper)

  9. 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.

  10. 10 GHz microstrip spanar antennas: an experimental analysis

    International Nuclear Information System (INIS)

    Othman, Mohd Azlishah; Azman, Hazwani; Husain, Mohd Nor; Aziz, Mohamad Zoinol Abidin Abd; Rahim, Yahaya Abd; Pee, Ahmad Nairn Che; Motsidi, Mohamad Radzi; Othman, Mohd Fairuz Iskandar

    2014-01-01

    This paper presents Spanar Antenna designed using CST Microwave Studio Simulation 2011. The proposed antenna was designed to operate at 10 GHz, which suggested return loss, S 11 must be less than -10 dB and voltage standing wave ratio (VSWR) must be less than 2. The best performance of simulation of Spanar Antenna was obtained at a small size of 24.8 mm × 8.0 mm with dimension board of FR4 substrate 31.7 mm × 18.5 mm. The thickness (h) and dielectric constant (εr) of substrate were 1.6 mm and 4.7. An analysis between simulation result and measurement result has been compared in order to see the antenna performance.

  11. A Novel Dual-Band Circularly Polarized Rectangular Slot Antenna

    Directory of Open Access Journals (Sweden)

    Biao Li

    2016-01-01

    Full Text Available A coplanar waveguide fed dual-band circularly polarized rectangular slot antenna is presented. The proposed antenna consists of a rectangular metal frame acting as a ground and an S-shaped monopole as a radiator. The spatial distribution of the surface current density is employed to demonstrate that the circular polarization is generated by the S-shaped monopole which controls the path of the surface currents. An antenna prototype, having overall dimension 37 × 37 × 1 mm3, has been fabricated on FR4 substrate with dielectric constant 4.4. The proposed antenna achieves 10 dB return loss bandwidths and 3 dB axial ratio (AR in the frequency bands 2.39–2.81 GHz and 5.42–5.92 GHz, respectively. Both these characteristics are suitable for WLAN and WiMAX applications.

  12. Phased array antenna control

    Science.gov (United States)

    Doland, G. D. (Inventor)

    1978-01-01

    Several new and useful improvements in steering and control of phased array antennas having a small number of elements, typically on the order of 5 to 17 elements are provided. Among the improvements are increasing the number of beam steering positions, reducing the possibility of phase transients in signals received or transmitted with the antennas, and increasing control and testing capacity with respect to the antennas.

  13. Experiments with dipole antennas

    International Nuclear Information System (INIS)

    Kraftmakher, Yaakov

    2009-01-01

    Employment of a data-acquisition system for data collection and calculations makes experiments with antennas more convenient and less time consuming. The determined directional patterns of the dipole antennas of different lengths are in reasonable agreement with theory. The enhancement of the signal by using a reflector is demonstrated, and a variant of the Yagi-Uda antenna is explored. The experiments are suitable as laboratory works and classroom demonstrations, and are attractive for student projects.

  14. Cellular Reflectarray Antenna

    Science.gov (United States)

    Romanofsky, Robert R.

    2010-01-01

    The cellular reflectarray antenna is intended to replace conventional parabolic reflectors that must be physically aligned with a particular satellite in geostationary orbit. These arrays are designed for specified geographical locations, defined by latitude and longitude, each called a "cell." A particular cell occupies nominally 1,500 square miles (3,885 sq. km), but this varies according to latitude and longitude. The cellular reflectarray antenna designed for a particular cell is simply positioned to align with magnetic North, and the antenna surface is level (parallel to the ground). A given cellular reflectarray antenna will not operate in any other cell.

  15. Compact Antenna Range

    Data.gov (United States)

    Federal Laboratory Consortium — Facility consists of a folded compact antenna range including a computer controlled three axis position table, parabolic reflector and RF sources for the measurement...

  16. ORNL compact loop antenna design for TFTR and Tore Supra

    International Nuclear Information System (INIS)

    Taylor, D.J.; Baity, F.W.; Bryan, W.E.; Hoffman, D.J.; McIlwain, R.L.; Ray, J.M.

    1987-01-01

    The goal supplemental ion cyclotron resonance heating (ICRH) of fusion plasma is to deliver power at high efficiencies deep within the plasma. The technology for fast-wave ICRH has reached the point of requiring ''proof-of-performance'' demonstration of specific antenna configurations of specific antenna configurations and their mechanical adequacy for operating in a fusion environment. Oak Ridge National Laboratory (ORNL) has developed the compact loop antenna concept based on a resonant double loop (RDL) configuration for use in both Tokamak Fusion Test Reactor (TFTR) and the Tore Supra ICRH programs. A description and a comparison of the technologies developed in the two designs are presented. The electrical circuit and the mechanical philosophy employed are the same for both antennas, but different operating environments result in substantial differences in the design of specific components. The ORNL TFTR antenna is designed to deliver 4 MW over a 2-s pulse, and the ORNL Tore Supra antenna is designed for 4 MW and essentially steady-state conditions. The TFTR design embodies the first operations compact RDL antenna, and the Tore Supra antenna extends the technology to an operational duty cycle consistent with reactor-relevant applications. 7 refs., 5 figs

  17. Numerical investigation of the electric field distribution and the power deposition in the resonant cavity of a microwave electrothermal thruster

    Directory of Open Access Journals (Sweden)

    Mehmet Serhan Yildiz

    2017-04-01

    Full Text Available Microwave electrothermal thruster (MET, an in-space propulsion concept, uses an electromagnetic resonant cavity as a heating chamber. In a MET system, electromagnetic energy is converted to thermal energy via a free floating plasma inside a resonant cavity. To optimize the power deposition inside the cavity, the factors that affect the electric field distribution and the resonance conditions must be accounted for. For MET thrusters, the length of the cavity, the dielectric plate that separates the plasma zone from the antenna, the antenna length and the formation of a free floating plasma have direct effects on the electromagnetic wave transmission and thus the power deposition. MET systems can be tuned by adjusting the lengths of the cavity or the antenna. This study presents the results of a 2-D axis symmetric model for the investigation of the effects of cavity length, antenna length, separation plate thickness, as well as the presence of free floating plasma on the power absorption. Specifically, electric field distribution inside the resonant cavity is calculated for a prototype MET system developed at the Bogazici University Space Technologies Laboratory. Simulations are conducted for a cavity fed with a constant power input of 1 kW at 2.45 GHz using COMSOL Multiphysics commercial software. Calculations are performed for maximum plasma electron densities ranging from 1019 to 1021 #/m3. It is determined that the optimum antenna length changes with changing plasma density. The calculations show that over 95% of the delivered power can be deposited to the plasma when the system is tuned by adjusting the cavity length.

  18. A Fully Inkjet Printed 3D Honeycomb Inspired Patch Antenna

    KAUST Repository

    McKerricher, Garret

    2015-07-16

    The ability to inkjet print three-dimensional objects with integrated conductive metal provides many opportunities for fabrication of radio frequency electronics and electronics in general. Both a plastic material and silver conductor are deposited by inkjet printing in this work. This is the first demonstration of a fully 3D Multijet printing process with integrated polymer and metal. A 2.4 GHz patch antenna is successfully fabricated with good performance proving the viability of the process. The inkjet printed plastic surface is very smooth, with less than 100 nm root mean square roughness. The printed silver nanoparticles are laser sintered to achieve adequate conductivity of 1e6 S/m while keeping the process below 80oC and avoiding damage to the polymer. The antenna is designed with a honeycomb substrate which minimizes material consumption. This reduces the weight, dielectric constant and dielectric loss which are all around beneficial. The antenna is entirely inkjet printed including the ground plane conductor and achieves an impressive 81% efficiency. The honeycomb substrate weighs twenty times less than a solid substrate. For comparison the honeycomb antenna provides an efficiency nearly 15% greater than a similarly fabricated antenna with a solid substrate.

  19. Directional borehole antenna - Theory

    International Nuclear Information System (INIS)

    Falk, L.

    1992-02-01

    A directional antenna has been developed for the borehole radar constructed during phase 2 of the Stripa project. The new antenna can determine the azimuth of a strong reflector with an accuracy of about 3 degrees as confirmed during experiments in Stripa, although the ratio of borehole diameter to wavelength is small, about 0.03. The antenna synthesizes the effect of a loop antenna rotating in the borehole from four signals measured in turn by a stationary antenna. These signals are also used to calculate an electric dipole signal and a check sum which is used to examine the function of the system. The theory of directional antennas is reviewed and used to design an antenna consisting of four parallel wires. The radiation pattern of this antenna is calculated using transmission line theory with due regard to polarization, which is of fundamental importance for the analysis of directional data. In particular the multipole expansion of the field is calculated to describe the antenna radiation pattern. Various sources of error, e.g. the effect of the borehole, are discussed and the methods of calibrating the antenna are reviewed. The ambiguity inherent in a loop antenna can be removed by taking the phase of the signal into account. Typical reflectors in rock, e.g. fracture zones an tunnels, may be modelled as simple geometrical structures. The corresponding analysis is described and exemplified on measurements from Stripa. Radar data is nowadays usually analyzed directly on the computer screen using the program RADINTER developed within the Stripa project. An algorithm for automatic estimation of the parameters of a reflector have been tested with some success. The relation between measured radar data and external coordinates as determined by rotational indicators is finally expressed in terms of Euler angles. (au)

  20. Applicability of point-dipoles approximation to all-dielectric metamaterials

    DEFF Research Database (Denmark)

    Kuznetsova, S. M.; Andryieuski, Andrei; Lavrinenko, Andrei

    2015-01-01

    All-dielectric metamaterials consisting of high-dielectric inclusions in a low-dielectric matrix are considered as a low-loss alternative to resonant metal-based metamaterials. In this paper we investigate the applicability of the point electric and magnetic dipoles approximation to dielectric meta......-atoms on the example of a dielectric ring metamaterial. Despite the large electrical size of high-dielectric meta-atoms, the dipole approximation allows for accurate prediction of the metamaterials properties for the rings with diameters up to approximate to 0.8 of the lattice constant. The results provide important...... guidelines for design and optimization of all-dielectric metamaterials....

  1. RFID antenna design for circular polarization in UHF band

    Science.gov (United States)

    Shahid, Hamza; Khan, Muhammad Talal Ali; Tayyab, Umais; Irshad, Usama Bin; Alkhazraji, Emad; Javaid, Muhammad Sharjeel

    2017-05-01

    A miniature half cross dipole antenna for defense and aerospace RFID applications in UHF band is presented. The dipole printed line arms are half crossed shape on top of dielectric substrate backed by reactive impedance surface. The antenna fed by a coaxial cable at the gap separating the dipole arms. Our design is intended to work at 2.42 GHz for RFID readers. The radiation pattern obtained has HPBW of 112, return loss of 22.24 dB and 90 MHz bandwidth.

  2. Finite difference time domain modeling of spiral antennas

    Science.gov (United States)

    Penney, Christopher W.; Beggs, John H.; Luebbers, Raymond J.

    1992-01-01

    The objectives outlined in the original proposal for this project were to create a well-documented computer analysis model based on the finite-difference, time-domain (FDTD) method that would be capable of computing antenna impedance, far-zone radiation patterns, and radar cross-section (RCS). The ability to model a variety of penetrable materials in addition to conductors is also desired. The spiral antennas under study by this project meet these requirements since they are constructed of slots cut into conducting surfaces which are backed by dielectric materials.

  3. 3D electromagnetic theory of ICRF multi PORT multi loop antenna

    International Nuclear Information System (INIS)

    Vdovin, V.L.; Kamenskij, I.V.

    1997-01-01

    In this report the theory of three dimensional antenna in Ion Cyclotron Resonance Frequency (ICRF) is developed for a plasma with circular magnetic surfaces. The multi loop antenna is located in ITER several ports. Circular plasma and antenna geometry provides new important tools to account for: 1) right loading antenna impedance matrix calculation urgently needed for a matching of RF generator with an antenna; 2) right calculation of an antenna toroidal and poloidal excited spectra because the DIFFRACTION, refraction and REFLECTION effects for the Fast Waves (FW) are in FIRST time are included self consistently in 3D ICRF antenna - plasma treatment; 3) right calculation of RF power deposition profiles because self consistently found 3D antenna - plasma FW excited spectra in non slab plasma model are important ones in a weakly dissipated plasma for Fast Waves (even for ITER parameters). (J.P.N.)

  4. Radiation quality factor of spherical antennas with material cores

    DEFF Research Database (Denmark)

    Hansen, Troels Vejle; Kim, Oleksiy S.; Breinbjerg, Olav

    2011-01-01

    This paper gives a description of the radiation quality factor and resonances of spherical antennas with material cores. Conditions for cavity and radiating resonances are given, and a theoretical description of the radiation quality factor, as well as simple expressions describing the relative...

  5. SIMULATED CHARACTERISTICS OF PATCH ANTENNA LOADED WITH SRRs

    OpenAIRE

    Debasis Mishra; G. Arun Kumar; D. R. Poddar; R. K. Mishra

    2010-01-01

    This article investigates, from electromagnetic simulation, the effects on gain and efficiency of a patch antenna loaded with split ring resonators. It is observed that it leads to lowering of resonant frequency; some mismatch resulting in a slight degradation of the impedance bandwidth and improvement of gain and efficiency.

  6. Handbook of antenna technologies

    CERN Document Server

    Liu, Duixian; Nakano, Hisamatsu; Qing, Xianming; Zwick, Thomas

    2016-01-01

    The Handbook of Antenna Technologies aims to present the rapid development of antenna technologies, particularly in the past two decades, and also showcasing the newly developed technologies and the latest applications. The handbook will provide readers with the comprehensive updated reference information covering theory, modeling and optimization methods, design and measurement, new electromagnetic materials, and applications of antennas. The handbook will widely cover not only all key antenna design issues but also fundamentals, issues related to antennas (transmission, propagation, feeding structure, materials, fabrication, measurement, system, and unique design challenges in specific applications). This handbook will benefit the readers as a full and quick technical reference with a high-level historic review of technology, detailed technical descriptions and the latest practical applications.

  7. GPS antenna designs

    Science.gov (United States)

    Laube, Samuel J. P.

    1987-05-01

    Application of the current GPS NAVSTAR system to civilian service requires that a right hand, circularly polarized, -160 dBW spread spectrum signal be received from an orbiting satellite, where the antenna environment is also moving. This presents a design challenge when inexpensive antennas are desired. The intent of this survey is to provide information on the antennas mentioned and to construct and test prototypes to determine whether the choice made by the industry, the quadrifilar helix, is the best. The helix antenna is currently the low cost standard for GPS. Prototype versions were constructed using 12 gauge wire and subminiature coaxial hardline. The constructed antennas were tested using a signal generator and a reference turnstile. A spectrum analyzer was used to measure the level of the received signal.

  8. Heating profiles on ICRF antenna Faraday shields

    International Nuclear Information System (INIS)

    Taylor, D.J.; Baity, F.W.; Hahs, C.L. Riemer, B.W.; Ryan, D.M.; Williamson, D.E.

    1992-01-01

    Poor definition of the heating profiles that occur during normal operation of Faraday shields for ion cyclotron resonant frequency (ICRF) antennas has complicated the mechanical design of ICRF system components. This paper reports that at Oak Ridge National Laboratory (ORNL), Faraday shield analysis is being used in defining rf heating profiles. In recent numerical analyses of proposed hardware for the Burning Plasma Experiment (BPX) and DIII-D, rf magnetic fields at Faraday shield surfaces were calculated, providing realistic predictions of the induced skin currents flowing on the shield elements and the resulting dissipated power profile. Detailed measurements on mock-ups of the Faraday shields for DIII-D and the Tokamak Fusion Test Reactor (TFTR) confirmed the predicted magnetic field distributions. A conceptual design for an uncooled Faraday shield for the BPX ion cyclotron resonance heating (ICRH) antenna, which should withstand the proposed long-pulse operation, has been completed. The analytical effort is described in detail, with emphasis on the design work for the BPX ICRH antenna conceptual design and for the replacement Faraday shield for the DIII-D FWCD antenna. Results of analyses are shown, and configuration issues involved in component modeling are discussed

  9. Smart antennas in aerospace applications

    NARCIS (Netherlands)

    Verpoorte, Jaco; Schippers, Harmen; Roeloffzen, C.G.H.; Marpaung, D.A.I.

    2010-01-01

    The interest in Smart Antennas for aerospace applications is growing. This paper describes smart antennas which can be used on aircraft. Two aerospace applications are discussed in more detail: a phased array antenna with optical beam forming and a large vibrating phased array antenna with

  10. Minimum Q circularly polarized electrically small spherical antennas

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.

    2011-01-01

    The radiation problem for the TM10- and TE10-mode electric current densities on the surface of a spherical magnetic-coated PEC core is solved analytically. The combination of the electric and magnetic dipole modes reduces the radiation Q of the antenna. Moreover, with an appropriately designed...... magnetic-coated PEC core the stored energies of these modes balance each other making the antenna self-resonant and at the same time ensuring a perfect circularly polarized radiation. Numerical results for a practical dual-mode electrically small antenna confirm the theoretical predictions. A 4-arm...

  11. 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

  12. 3D Inkjet Printed Helical Antenna with Integrated Lens

    KAUST Repository

    Farooqui, Muhammad Fahad

    2016-08-30

    The gain of an antenna can be enhanced through the integration of a lens, although this technique has traditionally been restricted to planar antennas due to fabrication limitations of standard manufacturing processes. Here, through a unique combination of 3D and 2D inkjet printing of dielectric and metallic inks respectively, we demonstrate a lens that has been monolithically integrated to a non-planar antenna (helix) for the first time. Antenna measurements show that the integration of a Fresnel lens enhances the gain of a 2-turn helix by around 4.6 dB, which provides a peak gain of about 12.9 dBi at 8.8 GHz. The 3-dB axial ratio (AR) bandwidth of the antenna with the lens is 5.5%. This work also reports the complete characterization of this new process in terms of minimum features sizes and achievable conductivities. Due to monolithic integration of the lens through a fully printed process, this antenna configuration offers high gain performance by using a low cost and rapid fabrication technique. © 2016 IEEE.

  13. A Design of Dual Broadband Antenna in Mobile Communication System

    Directory of Open Access Journals (Sweden)

    Jianming Zhou

    2015-01-01

    Full Text Available A design of dual broadband antenna is proposed in this paper; it consists of one low frequency unit and two high frequency units. The low frequency unit consists of a pair of printing vibrators; the high frequency unit consists of a pair of printing oscillators, which is bent at its end, and high frequency unit and low frequency unit are set on the same dielectric substrate. Through adding a parasitic unit on antenna, it can enhance frequency bandwidth without affecting the bandwidth. In the high frequency unit, it adopts gap-coupled microstrip line feeding method in order to get enough bandwidth. Through the test of dual broadband antenna, it can be found that, in the low frequency part, the antenna covers 20% bandwidth of the total bandwidth, and it covers the frequency from 800 MHz to 980 MHz. In the high frequency, the antenna covers 60% of total bandwidth and its frequency is from 1540 MHz to 2860 MHz, so the designed antenna can satisfy the frequency requirements of 2G/3G/LTE (4G communication system.

  14. Piezoelectric components wirelessly driven by dipole antenna-like electric field generator

    Energy Technology Data Exchange (ETDEWEB)

    Bhuyan, S., E-mail: elesatya@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Kumar, R.; Panda, S.K. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Hu, J. [Lab of Precision Drive, Nanjing University of Aeronautics and Astronautics, Nanjing 210026 (China)

    2011-08-25

    Highlights: > Wireless energy transmission technique. > Dipole antenna-like electric field generator. > Piezoelecctric resonance. > Finite element analyses. > Simulations and experimental verifications. - Abstract: A new technique of transmitting electric energy wirelessly to piezoelectric components by using a dipole antenna-like electric field generator is explored. Two square size brass plate-shaped live and ground electrodes are used to form a dipole antenna-like electric field generator. When the dipole antenna-like electric field generator in electric resonance with an inductor, a maximum output power of 2.72 mW and an energy conversion efficiency of 0.0174% have been achieved wirelessly by the piezoelectric plate area of 40 mm{sup 2} operating in the thickness vibration mode, placed at the center 4 mm away from the antenna plane with an optimum electrical load of 1365 {Omega}, resonant frequency of 782 kHz, 1 cm electrodes separation, 2500 cm{sup 2} electrode area of dipole antenna-like structure, and input ac source power of 15.58 W applied to the series of dipole antenna-like structure and inductor. The theoretically calculated results have been validated by the experimental studies. It is seen that at the resonance frequency and optimum electrical load, the output power of the wirelessly driven piezoelectric component decreases with the size of piezoelectric component, distance of piezoelectric component from the electrode of antenna plane, but increases with the antenna electrode area.

  15. Super dielectric capacitor using scaffold dielectric

    OpenAIRE

    Phillips, Jonathan

    2018-01-01

    Patent A capacitor having first and second electrodes and a scaffold dielectric. The scaffold dielectric comprises an insulating material with a plurality of longitudinal channels extending across the dielectric and filled with a liquid comprising cations and anions. The plurality of longitudinal channels are substantially parallel and the liquid within the longitudinal channels generally has an ionic strength of at least 0.1. Capacitance results from the migrations of...

  16. Monopole antenna in quantitative near-field microwave microscopy of planar structures

    International Nuclear Information System (INIS)

    Reznik, Alexander N.; Korolyov, Sergey A.

    2016-01-01

    We have developed an analytical model of a near-field microwave microscope based on a coaxial resonator with a sharpened tip probe. The probe interacts with a layered sample that features an arbitrary depth distribution of permittivity. The microscopic tip end with the accumulated charge is regarded as a monopole antenna radiating an electric field in near zone. The impedance of such an antenna is determined within a quasi-static approximation. The proposed model is used for calculating the sample-sensitive parameters of the microscope, specifically, resonance frequency f_0 and quality factor Q_0, as a function of probe-sample distance h. The theory has been verified experimentally in studies of semiconductor structures, both bulk and thin films. For measurements, we built a ∼2.1 GHz microscope with an effective tip radius of about 100 μm. The theoretical and experimental dependences f_0(h) and Q_0(h) were found to be in a good agreement. The developed theory underlies the method for determining sheet resistance R_s_h of a semiconductor film on a dielectric substrate proposed in this article. Studies were performed on doped n-GaN films on an Al_2O_3 substrate. The effective radius and height of the probe determined from calibration measurements of etalon samples were used as the model fitting parameters. For etalon samples, we employed homogeneous sapphire and doped silicon plates. We also performed four-probe dc measurements of R_s_h. The corresponding values for samples with R_s_h > 1 kΩ were found to be 50% to 100% higher than the microwave results, which are attributed to the presence of microdefects in semiconductor films.

  17. Dielectric nanostructures for broadband light trapping in organic solar cells

    KAUST Repository

    Raman, Aaswath; Yu, Zongfu; Fan, Shanhui

    2011-01-01

    or vice versa. Motivated by recent theoretical developments, we show that dielectric wavelength-scale grating structures can produce significant absorption resonances in a realistic organic cell architecture. We numerically demonstrate that 1D, 2D

  18. Dielectric-filled radiofrequency linacs

    Energy Technology Data Exchange (ETDEWEB)

    Faehl, R J; Keinigs, R K; Pogue, E W [Los Alamos National Lab., NM (United States)

    1997-12-31

    High current, high brightness electron beam accelerators promise to open up dramatic new applications. Linear induction accelerators are currently viewed as the appropriate technology for these applications. A concept by Humphries and Hwang may permit radiofrequency accelerators to fulfill the same functions with greater simplicity and enhanced flexibility. This concept involves the replacement of vacuum rf cavities with dielectric filled ones. Simple analysis indicates that the resonant frequencies are reduced by a factor of ({epsilon}{sub 0}/{epsilon}){sup 1/2} while the stored energy is increased by {epsilon}/{epsilon}{sub 0}. For a high dielectric constant like water, this factor can approach 80. A series of numerical calculations of simple pill-box cavities was performed. Eigenfunctions and resonant frequencies for a full system configuration, including dielectric material, vacuum beamline, and a ceramic window separating the two have been computed. These calculations are compared with the results of a small experimental cavity which have been constructed and operated. Low power tests show excellent agreement. (author). 4 figs., 8 refs.

  19. Antennas from theory to practice

    CERN Document Server

    Huang, Yi

    2008-01-01

    Practical, concise and complete reference for the basics of modern antenna design Antennas: from Theory to Practice discusses the basics of modern antenna design and theory. Developed specifically for engineers and designers who work with radio communications, radar and RF engineering, this book offers practical and hands-on treatment of antenna theory and techniques, and provides its readers the skills to analyse, design and measure various antennas. Key features: Provides thorough coverage on the basics of transmission lines, radio waves and propag

  20. An active antenna for ELF magnetic fields

    Science.gov (United States)

    Sutton, John F.; Spaniol, Craig

    1994-01-01

    The work of Nikola Tesla, especially that directed toward world-wide electrical energy distribution via excitation of the earth-ionosphere cavity resonances, has stimulated interest in the study of these resonances. Not only are they important for their potential use in the transmission of intelligence and electrical power, they are important because they are an integral part of our natural environment. This paper describes the design of a sensitive, untuned, low noise active antenna which is uniquely suited to modern earth-ionosphere cavity resonance measurements employing fast-Fourier transform techniques for near-real-time data analysis. It capitalizes on a little known field-antenna interaction mechanism. Recently, the authors made preliminary measurements of the magnetic fields in the earth-ionosphere cavity. During the course of this study, the problem of designing an optimized ELF magnetic field sensor presented itself. The sensor would have to be small, light weight (for portable use), and capable of detecting the 5-50 Hz picoTesla-level signals generated by the natural excitations of the earth-ionosphere cavity resonances. A review of the literature revealed that past researchers had employed very large search coils, both tuned and untuned. Hill and Bostick, for example, used coils of 30,000 turns wound on high permeability cores of 1.83 m length, weighing 40 kg. Tuned coils are unsuitable for modern fast-Fourier transform data analysis techniques which require a broad spectrum input. 'Untuned' coils connected to high input impedance voltage amplifiers exhibit resonant responses at the resonant frequency determined by the coil inductance and the coil distributed winding capacitance. Also, considered as antennas, they have effective areas equal only to their geometrical areas.

  1. Buoyant Cable Antenna System

    National Research Council Canada - National Science Library

    Gerhard, Erich M

    2008-01-01

    .... For instance, in one embodiment two oppositely extending curves each float and each are pressed by the water in a balanced manner to provide a stable platform for one or more antennas which can be...

  2. Micropatch Antenna Phase Shifting

    National Research Council Canada - National Science Library

    Thursby, Michael

    2000-01-01

    .... We have been looking at the ability of embedded element to adjust the phase shift seen by the element with the goal of being able to remove the phase shifting devices from the antenna and replace...

  3. Micropatch Antenna Phase Shifting

    National Research Council Canada - National Science Library

    Thursby, Michael

    1999-01-01

    .... We have been looking at the ability of embedded element to adjust the phase shift seen by the element wit the goal of being able to remove the phase shifting devices from the antenna and replace...

  4. Microwave antenna holography

    Science.gov (United States)

    Rochblatt, David J.; Seidel, Boris L.

    1992-01-01

    This microwave holography technique utilizes the Fourier transform relation between the complex far field radiation pattern of an antenna and the complex aperture field distribution. Resulting aperture phase and amplitude distribution data can be used to precisely characterize various crucial performance parameters, including panel alignment, panel shaping, subreflector position, antenna aperture illumination, directivity at various frequencies, and gravity deformation effects. The methodology of data processing presented here was successfully applied to the Deep Space Network (DSN) 34-m beam waveguide antennas. The antenna performance was improved at all operating frequencies by reducing the main reflector mechanical surface rms error to 0.43 mm. At Ka-band (32 GHz), the estimated improvement is 4.1 dB, resulting in an aperture efficiency of 52 percent. The performance improvement was verified by efficiency measurements and additional holographic measurements.

  5. Millimeter-wave sensor based on a λ/2-line resonator for identification and dielectric characterization of non-ionic surfactants.

    Science.gov (United States)

    Rodilla, H; Kim, A A; Jeffries, G D M; Vukusic, J; Jesorka, A; Stake, J

    2016-01-20

    Studies of biological and artificial membrane systems, such as niosomes, currently rely on the use of fluorescent tags, which can influence the system under investigation. For this reason, the development of label-free, non-invasive detection techniques is of great interest. We demonstrate an open-volume label-free millimeter-wave sensing platform based on a coplanar waveguide, developed for identification and characterization of niosome constituents. A design based on a λ/2-line resonator was used and on-wafer measurements of transmission and reflection parameters were performed up to 110 GHz. Our sensor was able to clearly distinguish between common niosome constituents, non-ionic surfactants Tween 20 and Span 80, measuring a resonance shift of 3 GHz between them. The complex permittivities of the molecular compounds have been extracted. Our results indicate insignificant frequency dependence in the investigated frequency range (3 GHz - 110 GHz). Values of permittivity around 3.0 + 0.7i and 2.2 + 0.4i were obtained for Tween 20 and Span 80, respectively.

  6. 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.

  7. Analysis and synthesis of (SAR) waveguide phased array antennas

    Science.gov (United States)

    Visser, H. J.

    1994-02-01

    This report describes work performed due to ESA contract No. 101 34/93/NL/PB. Started is with a literature study on dual polarized waveguide radiators, resulting in the choice for the open ended square waveguide. After a thorough description of the mode matching infinite waveguide array analysis method - including finiteness effects - that forms the basis for all further described analysis and synthesis methods, the accuracy of the analysis software is validated by comparison with measurements on two realized antennas. These antennas have centered irises in the waveguide apertures and a dielectric wide angle impedance matching sheet in front of the antenna. A synthesis method, using simulated annealing and downhill simplex, is described next and different antenna designs, based on the analysis of a single element in an infinite array environment, are presented. Next, designs of subarrays are presented. Shown is the paramount importance of including the array environment in the design of a subarray. A microstrip patch waveguide exciter and subarray feeding network are discussed and the depth of the waveguide radiator is estimated. Chosen is a rectangular grid array with waveguides of 2.5 cm depth without irises and without dielectric sheet, grouped in linear 8 elements subarrays.

  8. Large-Aperture Membrane Active Phased-Array Antennas

    Science.gov (United States)

    Karasik, Boris; McGrath, William; Leduc, Henry

    2009-01-01

    Large-aperture phased-array microwave antennas supported by membranes are being developed for use in spaceborne interferometric synthetic aperture radar systems. There may also be terrestrial uses for such antennas supported on stationary membranes, large balloons, and blimps. These antennas are expected to have areal mass densities of about 2 kg/sq m, satisfying a need for lightweight alternatives to conventional rigid phased-array antennas, which have typical areal mass densities between 8 and 15 kg/sq m. The differences in areal mass densities translate to substantial differences in total mass in contemplated applications involving aperture areas as large as 400 sq m. A membrane phased-array antenna includes patch antenna elements in a repeating pattern. All previously reported membrane antennas were passive antennas; this is the first active membrane antenna that includes transmitting/receiving (T/R) electronic circuits as integral parts. Other integral parts of the antenna include a network of radio-frequency (RF) feed lines (more specifically, a corporate feed network) and of bias and control lines, all in the form of flexible copper strip conductors on flexible polymeric membranes. Each unit cell of a prototype antenna (see Figure 1) contains a patch antenna element and a compact T/R module that is compatible with flexible membrane circuitry. There are two membrane layers separated by a 12.7-mm air gap. Each membrane layer is made from a commercially available flexible circuit material that, as supplied, comprises a 127-micron-thick polyimide dielectric layer clad on both sides with 17.5-micron-thick copper layers. The copper layers are patterned into RF, bias, and control conductors. The T/R module is located on the back side of the ground plane and is RF-coupled to the patch element via a slot. The T/R module is a hybrid multilayer module assembled and packaged independently and attached to the membrane array. At the time of reporting the information for

  9. High-directivity planar antenna using controllable photonic bandgap material at microwave frequencies

    International Nuclear Information System (INIS)

    de Lustrac, A.; Gadot, F.; Akmansoy, E.; Brillat, T.

    2001-01-01

    In this letter, we experimentally demonstrate the capability of a controllable photonic bandgap (CPBG) material to conform the emitted radiation of a planar antenna at 12 GHz. The CPBG material is a variable conductance lattice fabricated with high-frequency PIN diodes soldered along metallic stripes on dielectric printed boards. Depending on the diode bias, the emitted radiation of the antenna can be either transmitted or totally reflected by the material. In the transmission state, the antenna radiation is spatially filtered by the CPBG material in a sharp beam perpendicular to the surface of the material. [copyright] 2001 American Institute of Physics

  10. Wideband Tunable PIFA Antenna with Loaded Slot Structure for Mobile Handset and LTE Applications

    Directory of Open Access Journals (Sweden)

    I. Elfergani

    2014-04-01

    Full Text Available A compact planar inverted F antenna (PIFA with a tunable frequency response is presented. Tuning of the resonant frequency is realized by loading a varactor on an embedded slot of the proposed antenna structure without further optimizing other antenna geometry parameters. The antenna exhibits a wide frequency range from 1570 to 2600 MHz with a good impedance matching (S11 ≤-10 dB covering the GPS, PCS, DCS, UMTS, WLAN and LTE systems. To validate the theoretical model and design concept, the antenna prototype was fabricated and measured. The compact size of the antenna is 15mm × 8mm × 3mm, which makes this antenna a good candidate for mobile handset and wireless communication applications.

  11. Inertial polarization of dielectrics

    OpenAIRE

    Zavodovsky, A. G.

    2011-01-01

    It was proved that accelerated motion of a linear dielectric causes its polarization. Accelerated translational motion of a dielectric's plate leads to the positive charge of the surface facing the direction of motion. Metal plates of a capacitor were used to register polarized charges on a dielectric's surface. Potential difference between the capacitor plates is proportional to acceleration, when acceleration is constant potential difference grows with the increase of a dielectric's area, o...

  12. Optimal Super Dielectric Material

    Science.gov (United States)

    2015-09-01

    plate capacitor will reduce the net field to an unprecedented extent. This family of materials can form materials with dielectric values orders of... Capacitor -Increase Area (A)............8 b. Multi-layer Ceramic Capacitor -Decrease Thickness (d) .......10 c. Super Dielectric Material-Increase...circuit modeling, from [44], and B) SDM capacitor charge and discharge ...................................................22 Figure 15. Dielectric

  13. Miniaturized dual-band antenna array with double-negative (DNG) metamaterial for wireless applications

    Science.gov (United States)

    Alqadami, Abdulrahman Shueai Mohsen; Jamlos, Mohd Faizal; Soh, Ping Jack; Rahim, Sharul Kamal Abdul; Vandenbosch, Guy A. E.; Narbudowicz, Adam

    2017-01-01

    A miniaturized dual-band antenna array using a negative index metamaterial is presented for WiMAX, LTE, and WLAN applications. This left-handed metamaterial plane is located behind the antenna array, and its unit cell is a combination of split-ring resonator, square electric ring resonator, and rectangular electrical coupled resonator. This enables the achievement of a metamaterial structure exhibiting both negative permittivity and permeability, which results in antenna size miniaturization, efficiency, and gain enhancement. Moreover, the proposed metamaterial antenna has realized dual-band operating frequencies compared to a single frequency for normal antenna. The measured reflection coefficient (S11) shows a 50.25% bandwidth in the lower band (from 2.119 to 3.058 GHz) and 4.27% in the upper band (from 5.058 to 5.276 GHz). Radiation efficiency obtained in the lower and upper band are >95 and 80%, respectively.

  14. Antenna for Ultrawideband Channel Sounding

    DEFF Research Database (Denmark)

    Zhekov, Stanislav Stefanov; Tatomirescu, Alexandru; Pedersen, Gert F.

    2016-01-01

    A novel compact antenna for ultrawideband channel sounding is presented. The antenna is composed of a symmetrical biconical antenna modified by adding a cylinder and a ring to each cone. A feeding coaxial cable is employed during the simulations in order to evaluate and reduce its impact on the a......A novel compact antenna for ultrawideband channel sounding is presented. The antenna is composed of a symmetrical biconical antenna modified by adding a cylinder and a ring to each cone. A feeding coaxial cable is employed during the simulations in order to evaluate and reduce its impact...

  15. Smart Coat with a Fully-Embedded Textile Antenna for IoT Applications.

    Science.gov (United States)

    Loss, Caroline; Gonçalves, Ricardo; Lopes, Catarina; Pinho, Pedro; Salvado, Rita

    2016-06-22

    The Internet of Things (IoT) scenario is strongly related with the advance of the development of wireless sensor networks (WSN) and radio frequency identification (RFID) systems. Additionally, in the WSN context, for a continuous feed, the integration of textile antennas for energy harvesting into smart clothing is a particularly interesting solution when the replacement of batteries is not easy to practice, such as in wearable devices. This paper presents the E-Caption: Smart and Sustainable Coat. It has an embedded dual-band textile antenna for electromagnetic energy harvesting, operating at global system for mobile communication (GSM) 900 and digital cellular system (DCS) 1800 bands. This printed antenna is fully integrated, as its dielectric is the textile material composing the coat itself. The E-Caption illustrates the innovative concept of textile antennas that can be manipulated as simple emblems. Seven prototypes of these "emblem" antennas, manufactured by lamination and embroidering techniques are also presented. It is shown that the orientation of the conductive fabric does not influence the performance of the antenna. It is also shown that the direction and number of the stitches in the embroidery may influence the performance of the antenna. Moreover, the comparison of results obtained before and after the integration of the antenna into cloth shows the integration does not affect the behavior of the antenna.

  16. Smart Coat with a Fully-Embedded Textile Antenna for IoT Applications

    Directory of Open Access Journals (Sweden)

    Caroline Loss

    2016-06-01

    Full Text Available The Internet of Things (IoT scenario is strongly related with the advance of the development of wireless sensor networks (WSN and radio frequency identification (RFID systems. Additionally, in the WSN context, for a continuous feed, the integration of textile antennas for energy harvesting into smart clothing is a particularly interesting solution when the replacement of batteries is not easy to practice, such as in wearable devices. This paper presents the E-Caption: Smart and Sustainable Coat. It has an embedded dual-band textile antenna for electromagnetic energy harvesting, operating at global system for mobile communication (GSM 900 and digital cellular system (DCS 1800 bands. This printed antenna is fully integrated, as its dielectric is the textile material composing the coat itself. The E-Caption illustrates the innovative concept of textile antennas that can be manipulated as simple emblems. Seven prototypes of these “emblem” antennas, manufactured by lamination and embroidering techniques are also presented. It is shown that the orientation of the conductive fabric does not influence the performance of the antenna. It is also shown that the direction and number of the stitches in the embroidery may influence the performance of the antenna. Moreover, the comparison of results obtained before and after the integration of the antenna into cloth shows the integration does not affect the behavior of the antenna.

  17. 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

  18. Dielectrics in electric fields

    CERN Document Server

    Raju, Gorur G

    2003-01-01

    Discover nontraditional applications of dielectric studies in this exceptionally crafted field reference or text for seniors and graduate students in power engineering tracks. This text contains more than 800 display equations and discusses polarization phenomena in dielectrics, the complex dielectric constant in an alternating electric field, dielectric relaxation and interfacial polarization, the measurement of absorption and desorption currents in time domains, and high field conduction phenomena. Dielectrics in Electric Fields is an interdisciplinary reference and text for professionals and students in electrical and electronics, chemical, biochemical, and environmental engineering; physical, surface, and colloid chemistry; materials science; and chemical physics.

  19. Combline antenna modeling for plasma heating

    International Nuclear Information System (INIS)

    Nelson, S.D.; Kamin, G.; Van Maren, R.; Poole, B.; Moeller, C.; Phelps, D.

    1996-01-01

    The combline antenna for plasma heating, as proposed by General Atomics(1), has unique potential for solving many plasma drive problems. The benefit of the combline design is the utilization of the coupling between elements that avoids a more cumbersome multidrive system. This design is being investigated using computational EM modeling codes in the 100 endash 400 MHz band using resources at General Atomics and LLNL. Preliminary experimental results, using a combline mockup, agree well with 3D modeling efforts including resonant frequency alignment and amplitudes. These efforts have been expanded into an endeavor to optimize the combline design using both time and frequency domain codes. This analysis will include plasma coupling but to date has been limited to antenna effects. The combline antenna system is modeled in 3D using a combination of computational tools in the time domain, for temporal feature isolation purposes, and in the frequency domain, for resonant structure analysis. Both time and frequency domain modeling details include the Faraday shield elements, the strap elements, and the feed structure. copyright 1996 American Institute of Physics

  20. Analysis of a Waveguide-Fed Metasurface Antenna

    Science.gov (United States)

    Smith, David R.; Yurduseven, Okan; Mancera, Laura Pulido; Bowen, Patrick; Kundtz, Nathan B.

    2017-11-01

    The metasurface concept has emerged as an advantageous reconfigurable antenna architecture for beam forming and wave-front shaping, with applications that include satellite and terrestrial communications, radar, imaging, and wireless power transfer. The metasurface antenna consists of an array of metamaterial elements distributed over an electrically large structure, each subwavelength in dimension and with subwavelength separation between elements. In the antenna configuration we consider, the metasurface is excited by the fields from an attached waveguide. Each metamaterial element can be modeled as a polarizable dipole that couples the waveguide mode to radiation modes. Distinct from the phased array and electronically-scanned-antenna architectures, a dynamic metasurface antenna does not require active phase shifters and amplifiers but rather achieves reconfigurability by shifting the resonance frequency of each individual metamaterial element. We derive the basic properties of a one-dimensional waveguide-fed metasurface antenna in the approximation in which the metamaterial elements do not perturb the waveguide mode and are noninteracting. We derive analytical approximations for the array factors of the one-dimensional antenna, including the effective polarizabilities needed for amplitude-only, phase-only, and binary constraints. Using full-wave numerical simulations, we confirm the analysis, modeling waveguides with slots or complementary metamaterial elements patterned into one of the surfaces.

  1. 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.

  2. 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.

  3. ICRF current drive by using antenna phase control

    International Nuclear Information System (INIS)

    Kishimoto, Y.; Itoh, K.

    1987-01-01

    A global analysis of current drive in tokamaks by using waves in the ion cyclotron range of frequencies (ICRF), considering the entire antenna-plasma system, is presented. A phase shifted antenna array is used to inject toroidal momentum into the electrons. Within the context of quasi-linear theory, a Fokker-Planck calculation is combined with an ICRF wave propagation-absorption analysis which includes kinetic effects and realistic boundary conditions. The radial profile of the current induced by the mode converted ion Bernstein wave and by the magnetosonic fast wave is obtained, together with the global current drive efficiency (total induced current/total emitted power from the antennas) in the high density and temperature plasma regime. The phase dependence of the global efficiency is investigated by changing the launching conditions such as the total antenna number and the antenna spacing. In medium size tokamaks, the electron power absorption and the associated driven current are found to be affected considerably by the plasma cavity resonance. It is also found that the global efficiency is sensitive to the antenna spacing. When the antenna spacing is increased, the global efficiency is reduced by counter current generation. (author)

  4. Stretchable antenna for wearable electronics

    KAUST Repository

    Hussain, Muhammad Mustafa; Hussain, Aftab Mustansir; Shamim, Atif; Ghaffar, Farhan Abdul

    2017-01-01

    Various examples are provided for stretchable antennas that can be used for applications such as wearable electronics. In one example, a stretchable antenna includes a flexible support structure including a lateral spring section having a proximal

  5. Dynamic Flaps Electronic Scan Antenna

    National Research Council Canada - National Science Library

    Gonzalez, Daniel

    2000-01-01

    A dynamic FLAPS(TM) electronic scan antenna was the focus of this research. The novelty S of this SBIR resides in the use of plasma as the main component of this dynamic X-Band phased S array antenna...

  6. Multi-band Monopole Antennas Loaded with Metamaterial TL

    Science.gov (United States)

    Song, Zhi-jie; Liang, Jian-gang

    2015-05-01

    A novel metamaterial transmission line (TL) by loading complementary single Archimedean spiral resonator pair (CSASRP) is investigated and used to design a set of multi-frequency monopole antennas. The particularity is that the CSASRP which features dual-shunt branches in the equivalent circuit model is directly etched in the signal strip. By smartly controlling the element parameters, three antennas are designed and one of them covering UMTS and Bluetooth bands is fabricated and measured. The antenna exhibits impedance matching better than -10 dB and normal monopolar radiation patterns at working bands of 1.9-2.22 and 2.38-2.5 GHz. Moreover, the loaded element also contributes to the radiation, which is the major advantage of this prescription over previous lumped-element loadings. The proposed antenna is also more compact over previous designs.

  7. ICH antenna development on the ORNL RF Test Facility

    International Nuclear Information System (INIS)

    Gardner, W.L.; Bigelow, T.S.; Haste, G.R.; Hoffman, D.J.; Livesey, R.L.

    1987-01-01

    A compact resonant loop antenna is installed on the ORNL Radio Frequency Test Facility (RFTF). Facility characteristics include a steady-state magnetic field of ∼ 0.5 T at the antenna, microwave-generated plasmas with n e ∼ 10 12 cm -3 and T e ∼ 8 eV, and 100 kW of 25-MHz rf power. The antenna is tunable from ∼22--75 MHz, is designed to handle ≥1 MW of rf power, and can be moved 5 cm with respect to the port flange. Antenna characteristics reported and discussed include the effect of magnetic field on rf voltage breakdown at the capacitor, the effects of magnetic field and plasma on rf voltage breakdown between the radiating element and the Faraday shield, the effects of graphite on Faraday shield losses, and the efficiency of coupling to the plasma. 2 refs., 4 figs

  8. Integrated, Dual Orthogonal Antennas for Polarimetric Ground Penetrating Radar

    Science.gov (United States)

    Pauli, Mario; Wiesbeck, Werner

    2015-04-01

    Ground penetrating radar systems are mostly equipped with single polarized antennas, for example with single linear polarization or with circular polarization. The radiated waves are partly reflected at the ground surface and very often the penetrating waves are distorted in their polarization. The distortion depends on the ground homogeneity and the orientation of the antennas relative to the ground structure. The received signals from the reflecting objects may most times only be classified according to their coverage and intensity. This makes the recognition of the objects difficult or impossible. In airborne and spaceborne Remote Sensing the systems are meanwhile mostly equipped with front ends with dual orthogonal polarized antennas for a full polarimetric operation. The received signals, registered in 2x2 scattering matrices according to co- and cross polarization, are processed for the evaluation of all features of the targets. Ground penetrating radars could also profit from the scientific results of Remote Sensing. The classification of detected objects for their structure and orientation requires more information in the reflected signal than can be measured with a single polarization [1, 2]. In this paper dual linear, orthogonal polarized antennas with a common single, frequency independent phase center, are presented [3]. The relative bandwidth of these antennas can be 1:3, up to 1:4. The antenna is designed to work in the frequency range between 3 GHz and 11 GHz, but can be easily adapted to the GPR frequency range by scaling. The size of the antenna scaled for operation in typical GPR frequencies would approximately be 20 by 20 cm2. By the implementation in a dielectric carrier it could be reduced in size if required. The major problem for ultra wide band, dual polarized antennas is the frequency independent feed network, realizing the required phase shifts. For these antennas a network, which is frequency independent over a wide range, has been

  9. Dielectric loss against piezoelectric power harvesting

    Science.gov (United States)

    Liang, Junrui; Shu-Hung Chung, Henry; Liao, Wei-Hsin

    2014-09-01

    Piezoelectricity is one of the most popular electromechanical transduction mechanisms for constructing kinetic energy harvesting systems. When a standard energy harvesting (SEH) interface circuit, i.e., bridge rectifier plus filter capacitor, is utilized for collecting piezoelectric power, the previous literature showed that the power conversion can be well predicted without much consideration for the effect of dielectric loss. Yet, as the conversion power gets higher by adopting power-boosting interface circuits, such as synchronized switch harvesting on inductor (SSHI), the neglect of dielectric loss might give rise to deviation in harvested power estimation. Given the continuous progress on power-boosting interface circuits, the role of dielectric loss in practical piezoelectric energy harvesting (PEH) systems should receive attention with better evaluation. Based on the integrated equivalent impedance network model, this fast track communication provides a comprehensive study on the susceptibility of harvested power in PEH systems under different conditions. It shows that, dielectric loss always counteracts piezoelectric power harvesting by causing charge leakage across piezoelectric capacitance. In particular, taking corresponding ideal lossless cases as references, the counteractive effect might be aggravated under one of the five conditions: larger dielectric loss tangent, lower vibration frequency, further away from resonance, weaker electromechanical coupling, or using power-boosting interface circuit. These relationships are valuable for the study of PEH systems, as they not only help explain the role of dielectric loss in piezoelectric power harvesting, but also add complementary insights for material, structure, excitation, and circuit considerations towards holistic evaluation and design for practical PEH systems.

  10. Preliminary measurements with a 4 K gravitational wave antenna

    International Nuclear Information System (INIS)

    Boughn, S.P.; McAshan, M.S.; Paik, H.J.; Taber, R.C.; Fairbank, W.M.; Giffard, R.P.

    1975-01-01

    The behavior of a small resonant gravitational wave antenna cooled to 4 K has been measured. This antenna is the prototype for a much larger system designed to be cooled eventually below 10 mK. Noise levels have been observed in the fundamental mechanical mode of the antenna corresponding to temperatures below 50 K. The antenna is a 680 kg cylindrical bar of aluminum clad with a layer of 0.38 mm thick niobium-titanium. It is levitated on a magnetic field of 0.2 T provided by a set of curved superconducting coils. The helium tank is suspended by low resonant-frequency springs and acoustic isolation stacks constructed of alternate layers of rubber and iron. This suspension is mechanically independent of the rest of the cryostat. Measurements have shown that the magnetic levitation stage provides a further vibration attenuation in excess of 50 dB at the frequency of the antenna mode. When levitated at an exchange gas pressure of 0.01 Pa the energy decay time for the fundamental bar mode at 1312 Hz has been measured to be 40 s. This corresponds to a Q of 3.3 x 10 5 . For the experiments to be described the bar carries at one end an acceleration transducer, operating in a non-resonant mode. (Auth.)

  11. Wireless Distributed Antenna MIMO

    DEFF Research Database (Denmark)

    2015-01-01

    The present disclosure relates to system applications of multicore optical fibers. One embodiment relates to a base transceiver station for a wireless telecommunication system comprising a plurality of antenna units arranged in a MIMO configuration and adapted for transmission and/or reception...... of radio-frequency signals, an optical transmitter in the form of an electro-optic conversion unit for each of said plurality of antenna units, each electro-optic conversion unit adapted for converting an RF signal into an optical signal, a plurality of a single core optical fibers for guiding the optical...

  12. Printed MIMO antenna engineering

    CERN Document Server

    Sharawi, Mohammad S

    2014-01-01

    Wireless communications has made a huge leap during the past two decades. The multiple-input-multiple-output (MIMO) technology was proposed in the 1990's as a viable solution that can overcome the data rate limit experienced by single-input-single-output (SISO) systems. This resource is focused on printed MIMO antenna system design. Printed antennas are widely used in mobile and handheld terminals due to their conformity with the device, low cost, good integration within the device elements and mechanical parts, as well as ease of fabrication.A perfect design companion for practicing engineers

  13. Non-standard antennas

    CERN Document Server

    Le Chevalier, Francois; Staraj, Robert

    2013-01-01

    This book aims at describing the wide variety of new technologies and concepts of non-standard antenna systems - reconfigurable, integrated, terahertz, deformable, ultra-wideband, using metamaterials, or MEMS,  etc, and how they open the way to a wide range of applications, from personal security and communications to multifunction radars and towed sonars, or satellite navigation systems, with space-time diversity on transmit and receive. A reference book for designers  in this lively scientific community linking antenna experts and signal processing engineers.

  14. DSN Microwave Antenna Holography

    Science.gov (United States)

    Rochblatt, D. J.; Seidel, B. L.

    1984-01-01

    The DSN microwave antenna holography project will obtain three-dimensional pictures of the large DSN antenna surfaces. These pictures must be of suffi icient resolution to allow adjustment of the reflector panels to an rms surface of 0.5 mm (0.25 mm, goal). The major parameters and equations needed to define a holographic measurement system are outlined and then the proof of concept demonstration measurement that was made at DSS-43 (Australia) that resulted in contour maps with spatial resolution of 7 m in the aperture plane and resolution orthogonal to the aperture plane of 0.7 mm was discussed.

  15. Passive wireless antenna sensor for strain and crack sensing—electromagnetic modeling, simulation, and testing

    International Nuclear Information System (INIS)

    Yi, Xiaohua; Cho, Chunhee; Wang, Yang; Cooper, James; Tentzeris, Manos M; Leon, Roberto T

    2013-01-01

    This research investigates a passive wireless antenna sensor designed for strain and crack sensing. When the antenna experiences deformation, the antenna shape changes, causing a shift in the electromagnetic resonance frequency of the antenna. A radio frequency identification (RFID) chip is adopted for antenna signal modulation, so that a wireless reader can easily distinguish the backscattered sensor signal from unwanted environmental reflections. The RFID chip captures its operating power from an interrogation electromagnetic wave emitted by the reader, which allows the antenna sensor to be passive (battery-free). This paper first reports the latest simulation results on radiation patterns, surface current density, and electromagnetic field distribution. The simulation results are followed with experimental results on the strain and crack sensing performance of the antenna sensor. Tensile tests show that the wireless antenna sensor can detect small strain changes lower than 20 με, and can perform well at large strains higher than 10 000 με. With a high-gain reader antenna, the wireless interrogation distance can be increased up to 2.1 m. Furthermore, an array of antenna sensors is capable of measuring the strain distribution in close proximity. During emulated crack and fatigue crack tests, the antenna sensor is able to detect the growth of a small crack. (paper)

  16. Structuring Light to Manipulate Multipolar Resonances for Metamaterial Applications

    Science.gov (United States)

    Das, Tanya

    Multipolar electromagnetic phenomena in sub-wavelength resonators are at the heart of metamaterial science and technology. Typically, researchers engineer multipolar light-matter interactions by modifying the size, shape, and composition of the resonators. Here, we instead engineer multipolar interactions by modifying properties of the incident radiation. In this dissertation, we propose a new framework for determining the scattering response of resonators based on properties of the local excitation field. First, we derive an analytical theory to determine the scattering response of spherical nanoparticles under any type of illumination. Using this theory, we demonstrate the ability to drastically manipulate the scattering properties of a spherical nanoparticle by varying the illumination and demonstrate excitation of a longitudinal quadrupole mode that cannot be accessed with conventional illumination. Next, we investigate the response of dielectric dimer structures illuminated by cylindrical vector beams. Using finite-difference time-domain simulations, we demonstrate significant modification of the scattering spectra of dimer antennas and reveal how the illumination condition gives rise to these spectra through manipulation of electric and magnetic mode hybridization. Finally, we present a simple and efficient numerical simulation based on local field principles for extracting the multipolar response of any resonator under illumination by structured light. This dissertation enhances the understanding of fundamental light-matter interactions in metamaterials and lays the foundation for researchers to identify, quantify, and manipulate multipolar light-matter interactions through optical beam engineering.

  17. Optical response of bowtie antennas

    Science.gov (United States)

    Guo, Ying-Nan; Pan, Shi; Li, Xu-Feng; Wang, Shuo; Wang, Qiao

    2010-10-01

    Optical properties of bowtie antennas are investigated using a numerical method of finite-difference time-domain (FDTD). The optical response in the antenna feed gap is simulated as functions of its geometry parameters (flare angle, arm length, apex width, thickness, gap dimension, as well as the index of substrate), which provide a clear guideline to exploit such antenna structures in practice.

  18. A wireless interrogation system exploiting narrowband acoustic resonator for remote physical quantity measurement

    International Nuclear Information System (INIS)

    Friedt, J.-M; Droit, C.; Martin, G.; Ballandras, S.

    2010-01-01

    Monitoring physical quantities using acoustic wave devices can be advantageously achieved using the wave characteristic dependence to various parametric perturbations (temperature, stress, and pressure). Surface acoustic wave (SAW) resonators are particularly well suited to such applications as their resonance frequency is directly influenced by these perturbations, modifying both the phase velocity and resonance conditions. Moreover, the intrinsic radio frequency (rf) nature of these devices makes them ideal for wireless applications, mainly exploiting antennas reciprocity and piezoelectric reversibility. In this paper, we present a wireless SAW sensor interrogation unit operating in the 434 MHz centered ISM band--selected as a tradeoff between antenna dimensions and electromagnetic wave penetration in dielectric media--based on the principles of a frequency sweep network analyzer. We particularly focus on the compliance with the ISM standard which reveals complicated by the need for switching from emission to reception modes similarly to radar operation. In this matter, we propose a fully digital rf synthesis chain to develop various interrogation strategies to overcome the corresponding difficulties and comply with the above-mentioned standard. We finally assess the reader interrogation range, accuracy, and dynamics.

  19. A wireless interrogation system exploiting narrowband acoustic resonator for remote physical quantity measurement

    Energy Technology Data Exchange (ETDEWEB)

    Friedt, J.-M [SENSeOR, 32 Avenue de l' Observatoire, 25044 Besancon (France); Droit, C.; Martin, G.; Ballandras, S. [Department of Time and Frequency, FEMTO-ST, 32 Avenue de l' Observatoire, 25044 Besancon (France)

    2010-01-15

    Monitoring physical quantities using acoustic wave devices can be advantageously achieved using the wave characteristic dependence to various parametric perturbations (temperature, stress, and pressure). Surface acoustic wave (SAW) resonators are particularly well suited to such applications as their resonance frequency is directly influenced by these perturbations, modifying both the phase velocity and resonance conditions. Moreover, the intrinsic radio frequency (rf) nature of these devices makes them ideal for wireless applications, mainly exploiting antennas reciprocity and piezoelectric reversibility. In this paper, we present a wireless SAW sensor interrogation unit operating in the 434 MHz centered ISM band--selected as a tradeoff between antenna dimensions and electromagnetic wave penetration in dielectric media--based on the principles of a frequency sweep network analyzer. We particularly focus on the compliance with the ISM standard which reveals complicated by the need for switching from emission to reception modes similarly to radar operation. In this matter, we propose a fully digital rf synthesis chain to develop various interrogation strategies to overcome the corresponding difficulties and comply with the above-mentioned standard. We finally assess the reader interrogation range, accuracy, and dynamics.

  20. Gold nanoparticles extraction from dielectric scattering background

    Science.gov (United States)

    Hong, Xin; Wang, Jingxin

    2014-11-01

    The unique advantages such as brightness, non-photobleaching, good bio-compatibility make gold nanoparticles desirable labels and play important roles in biotech and related research and applications. Distinguishing gold nanoparticles from other dielectric scattering particles is of more importance, especially in bio-tracing and imaging. The enhancement image results from the localized surface plasmon resonance associated with gold nanopartilces makes themselves distinguishable from other dielectric particles, based on which, we propose a dual-wavelength detection method by employing a high sensitive cross-polarization microscopy.

  1. An inkjet printed meandered dipole antenna for RF passive sensing applications

    KAUST Repository

    Quddious, Abdul

    2016-04-10

    In this paper, a low cost inkjet printed antenna envisioned for integration with printed and non-printed RF sensors is presented. The proposed meandered dipole dual-loop antenna is designed on a 0.25mm thick paper substrate. The antenna not only gives wireless remote sensing capability but also allows remote identification functionality. The antenna structure consists of an outer loop and an inner loop resonating at 3GHz and 5GHz respectively and used for obtaining unique electromagnetic signature by modifications in their dimensions.

  2. MIMO channel capacity versus mutual coupling in multi antenna element system

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2004-01-01

    In this paper the influence of mutual coupling on the capacity of a multiple-input multiple-output (MIMO) antenna system is demonstrated. No direct relation between the envelope correlation and the actual location and orientation of the antennas is found. Even though being essential for high MIMO...... capacity, configurations with the lowest envelope correlations are not necessarily the most suitable for a MIMO system. A certain bandwidth is required as well. Three planar inverted F-antennas (PIFA) located on the same 40 mm x 100 mm ground plane. The antennas that haves a resonant frequency of 1.8 GHz...

  3. Electromagnetic reciprocity in antenna theory

    CERN Document Server

    Stumpf, Martin

    2018-01-01

    The reciprocity theorem is among the most intriguing concepts in wave field theory and has become an integral part of almost all standard textbooks on electromagnetic (EM) theory. This book makes use of the theorem to quantitatively describe EM interactions concerning general multiport antenna systems. It covers a general reciprocity-based description of antenna systems, their EM scattering properties, and further related aspects. Beginning with an introduction to the subject, Electromagnetic Reciprocity in Antenna Theory provides readers first with the basic prerequisites before offering coverage of the equivalent multiport circuit antenna representations, EM coupling between multiport antenna systems and their EM interactions with scatterers, accompanied with the corresponding EM compensation theorems.

  4. Antenna theory analysis and design

    CERN Document Server

    Balanis, Constantine A

    2005-01-01

    The discipline of antenna theory has experienced vast technological changes. In response, Constantine Balanis has updated his classic text, Antenna Theory, offering the most recent look at all the necessary topics. New material includes smart antennas and fractal antennas, along with the latest applications in wireless communications. Multimedia material on an accompanying CD presents PowerPoint viewgraphs of lecture notes, interactive review questions, Java animations and applets, and MATLAB features. Like the previous editions, Antenna Theory, Third Edition meets the needs of e

  5. Characterization of dielectric materials

    Energy Technology Data Exchange (ETDEWEB)

    King, Danny J.; Babinec, Susan; Hagans, Patrick L.; Maxey, Lonnie C.; Payzant, Edward A.; Daniel, Claus; Sabau, Adrian S.; Dinwiddie, Ralph B.; Armstrong, Beth L.; Howe, Jane Y.; Wood, III, David L.; Nembhard, Nicole S.

    2017-06-27

    A system and a method for characterizing a dielectric material are provided. The system and method generally include applying an excitation signal to electrodes on opposing sides of the dielectric material to evaluate a property of the dielectric material. The method can further include measuring the capacitive impedance across the dielectric material, and determining a variation in the capacitive impedance with respect to either or both of a time domain and a frequency domain. The measured property can include pore size and surface imperfections. The method can still further include modifying a processing parameter as the dielectric material is formed in response to the detected variations in the capacitive impedance, which can correspond to a non-uniformity in the dielectric material.

  6. Effective Length of a Receiving Antenna in a Streaming Plasma

    Czech Academy of Sciences Publication Activity Database

    Chugunov, Yu. V.; Fiala, Vladimír

    2006-01-01

    Roč. 54, č. 10 (2006), s. 2750-2756 ISSN 0018-926X R&D Projects: GA AV ČR IAA301120601 Institutional research plan: CEZ:AV0Z30420517 Keywords : receiving antenna * plasma waves * resonance Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.480, year: 2006

  7. Metallic dielectric photonic crystals and methods of fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Jeffrey Brian; Kim, Sang-Gook

    2016-12-20

    A metallic-dielectric photonic crystal is formed with a periodic structure defining a plurality of resonant cavities to selectively absorb incident radiation. A metal layer is deposited on the inner surfaces of the resonant cavities and a dielectric material fills inside the resonant cavities. This photonic crystal can be used to selectively absorb broadband solar radiation and then reemit absorbed radiation in a wavelength band that matches the absorption band of a photovoltaic cell. The photonic crystal can be fabricated by patterning a sacrificial layer with a plurality of holes, into which is deposited a supporting material. Removing the rest of the sacrificial layer creates a supporting structure, on which a layer of metal is deposited to define resonant cavities. A dielectric material then fills the cavities to form the photonic crystal.

  8. Metallic dielectric photonic crystals and methods of fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Jeffrey Brian; Kim, Sang-Gook

    2017-12-05

    A metallic-dielectric photonic crystal is formed with a periodic structure defining a plurality of resonant cavities to selectively absorb incident radiation. A metal layer is deposited on the inner surfaces of the resonant cavities and a dielectric material fills inside the resonant cavities. This photonic crystal can be used to selectively absorb broadband solar radiation and then reemit absorbed radiation in a wavelength band that matches the absorption band of a photovoltaic cell. The photonic crystal can be fabricated by patterning a sacrificial layer with a plurality of holes, into which is deposited a supporting material. Removing the rest of the sacrificial layer creates a supporting structure, on which a layer of metal is deposited to define resonant cavities. A dielectric material then fills the cavities to form the photonic crystal.

  9. Enhanced transmission through arrays of subwavelength holes in gold films coated by a finite dielectric layer

    DEFF Research Database (Denmark)

    Xiao, Sanshui; Mortensen, Niels Asger; Qiu, M.

    2007-01-01

    resonances attributing to the enhanced transmission: the localized waveguide resonance and periodic surface plasmon resonances. For the film coated with dielectric layers, calculated results show that in the wavelength region of interest the localized waveguide resonant mode attributes to sensing rather than...

  10. Design and Development of Aerogel-Based Antennas for Aerospace Applications: A Final Report to the NARI Seedling

    Science.gov (United States)

    Meador, Mary Ann B.; Miranda, Felix A.

    2014-01-01

    As highly porous solids possessing low density and low dielectric permittivity combined with good mechanical properties, polyimide (PI) aerogels offer great promise as an enabling technology for lightweight aircraft antenna systems. While they have been aggressively explored for thermal insulation, barely any effort has been made to leverage these materials for antennas or other applications that take advantage of their aforementioned attributes. In Phase I of the NARI Seedling Project, we fabricated PI aerogels with properties tailored to enable new antenna concepts with performance characteristics (wide bandwidth and high gain) and material properties (low density, environmental stability, and robustness) superior to the state of practice (SOP). We characterized electromagnetic properties, including permittivity, reflectivity, and propagation losses for the aerogels. Simple, prototype planar printed circuit patch antennas from down-selected aerogel formulations were fabricated by molding the aerogels to net shapes and by gold-metalizing the pattern onto the templates via electron beam evaporation in a clean room environment. These aerogel based antennas were benchmarked against current antenna SOP, and exhibited both broader bandwidth and comparable or higher gain performance at appreciably lower mass. Phase II focused on the success of the Phase I results pushing the PI aerogel based antenna technology further by exploring alternative antenna design (i.e., slot coupled antennas) and by examining other techniques for fabricating the antennas including ink jet printing with the goal of optimizing antenna performance and simplifying production. We also examined new aerogel formulations with better moisture and solvent resistance to survive processing conditions. In addition, we investigated more complex antenna designs including passive phased arrays such as 2x4 and 4x8 element arrays to assess the scalability of the aerogel antenna concept. Furthermore, we

  11. Inductive dielectric analyzer

    International Nuclear Information System (INIS)

    Agranovich, Daniel; Popov, Ivan; Ben Ishai, Paul; Feldman, Yuri; Polygalov, Eugene

    2017-01-01

    One of the approaches to bypass the problem of electrode polarization in dielectric measurements is the free electrode method. The advantage of this technique is that, the probing electric field in the material is not supplied by contact electrodes, but rather by electromagnetic induction. We have designed an inductive dielectric analyzer based on a sensor comprising two concentric toroidal coils. In this work, we present an analytic derivation of the relationship between the impedance measured by the sensor and the complex dielectric permittivity of the sample. The obtained relationship was successfully employed to measure the dielectric permittivity and conductivity of various alcohols and aqueous salt solutions. (paper)

  12. Method of making dielectric capacitors with increased dielectric breakdown strength

    Science.gov (United States)

    Ma, Beihai; Balachandran, Uthamalingam; Liu, Shanshan

    2017-05-09

    The invention is directed to a process for making a dielectric ceramic film capacitor and the ceramic dielectric laminated capacitor formed therefrom, the dielectric ceramic film capacitors having increased dielectric breakdown strength. The invention increases breakdown strength by embedding a conductive oxide layer between electrode layers within the dielectric layer of the capacitors. The conductive oxide layer redistributes and dissipates charge, thus mitigating charge concentration and micro fractures formed within the dielectric by electric fields.

  13. 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.

  14. Analysis and design of the Alfven wave antenna system for the SUNIST spherical tokamak

    International Nuclear Information System (INIS)

    Tan Yi; Gao Zhe; He Yexi

    2009-01-01

    Analysis and design of the Alfven wave antenna system for the SUNIST spherical tokamak are presented. Two candidate antenna concepts, folded and unfolded, are analyzed and compared with each other. In the frequency range of Alfven resonance the impedance spectrums of both two concept antennas for major modes are numerically calculated in a 1-D MHD framework. The folded concept is chosen for engineering design. The antenna system is designed to be simple and requires least modification to the vacuum vessel. The definition of the antenna shape is guided by the analyses with constraints of existing hardware layouts. Each antenna unit consists of two stainless steel straps with a thickness of 1 mm. A number of boron nitride tiles are assembled together as the side limiters for plasma shielding. Estimation shows that the structure is robust enough to withstand the electromagnetic force and the heat load for typical discharge duty cycles.

  15. Multiple Antenna Systems with Inherently Decoupled Radiators

    DEFF Research Database (Denmark)

    Pelosi, Mauro; Knudsen, Mikael B.; Pedersen, Gert Frølund

    2012-01-01

    In multiple antenna systems mutual coupling needs to be minimized. We propose an alternative novel decoupling technique, investigating several multiple antenna configurations for small handsets through measurements and numerical simulations. The influence of different novel designs on performance...... metrics such as total loss, antenna isolation and envelope correlation coefficient are investigated. By varying antenna impedance bandwidth and antenna location with respect to the handset, both Planar Inverted F Antenna (PIFA) and Inverted F Antennas (IFA) were investigated in different UMTS frequency...

  16. Antenna-load interactions at optical frequencies: impedance matching to quantum systems.

    Science.gov (United States)

    Olmon, R L; Raschke, M B

    2012-11-09

    The goal of antenna design at optical frequencies is to deliver optical electromagnetic energy to loads in the form of, e.g., atoms, molecules or nanostructures, or to enhance the radiative emission from such structures, or both. A true optical antenna would, on a qualitatively new level, control the light-matter interaction on the nanoscale for controlled optical signal transduction, radiative decay engineering, quantum coherent control, and super-resolution microscopy, and provide unprecedented sensitivity in spectroscopy. Resonant metallic structures have successfully been designed to approach these goals. They are called optical antennas in analogy to radiofrequency (RF) antennas due to their capability to collect and control electromagnetic fields at optical frequencies. However, in contrast to the RF, where exact design rules for antennas, waveguides, and antenna-load matching in terms of their impedances are well established, substantial physical differences limit the simple extension of the RF concepts into the optical regime. Key distinctions include, for one, intrinsic material resonances including quantum state excitations (metals, metal oxides, semiconductor homo- and heterostructures) and extrinsic resonances (surface plasmon/phonon polaritons) at optical frequencies. Second, in the absence of discrete inductors, capacitors, and resistors, new design strategies must be developed to impedance match the antenna to the load, ultimately in the form of a vibrational, electronic, or spin excitation on the quantum level. Third, there is as yet a lack of standard performance metrics for characterizing, comparing and quantifying optical antenna performance. Therefore, optical antenna development is currently challenged at all the levels of design, fabrication, and characterization. Here we generalize the ideal antenna-load interaction at optical frequencies, characterized by three main steps: (i) far-field reception of a propagating mode exciting an antenna

  17. ICRF antenna Faraday shield plasma sheath model

    International Nuclear Information System (INIS)

    Whealton, J.H.; Ryan, P.M.; Raridon, R.J.

    1990-01-01

    A two-dimensional nonlinear formulation that explicitly considers the plasma edge near a Faraday shield in a self-consistent manner is used in the modeling of the ion motion for a Faraday shield concept and model suggested by Perkins. Two models are considered that may provide significant insight into the generation of impurities for ion cyclotron resonance heating (ICRH) antennas. In one of these models a significant sheath periodically forms next to the Faraday screen, with ion acoustic waves heating the ions in the plasma. (orig.)

  18. Interaction of a parametric transducer with a resonant bar gravitational radiation detector

    International Nuclear Information System (INIS)

    Linthorne, N.P.; Veitch, P.J.; Blair, D.G.

    1990-01-01

    It is shown that a microwave parametric transducer for a resonant bar gravitational radiation antenna can achieve high electromechanical coupling without degrading the acoustic Q of the antenna. The reactive coupling of the transducer to the antenna leads to both cold-damping and modification of the antenna's resonant frequency. These effects are examined in a 1.5 tonne niobium resonant bar antenna. At low coupling the observed behaviour is found to be in good agreement with theory. At higher coupling, the behaviour is complicated by other effects. We discuss how these parametric effects may be used to advantage when suitably controlled. (author)

  19. Broadband Monopole Antenna

    Science.gov (United States)

    2017-09-14

    December 2017 The below identified patent application is available for licensing. Requests for information should be addressed to...CROSS REFERENCE TO OTHER PATENT APPLICATIONS [0002] United States Patent Application Ser. No. 15/220,692 filed on July 27, 2016 is incorporated by...antenna operating near 2.5 GHz to obtain an octave of bandwidth. One solution for this is given by Werner et al. in United States Patent

  20. Design and Optimization of Passive UHF RFID Tag Antenna for Mounting on or inside Material Layers

    Science.gov (United States)

    Shao, Shuai

    There is great desire to employ passive UHF RFID tags for inventory tracking and sensing in a diversity of applications and environments. Owing to its battery-free operation, non-line-of sight detection, low cost, long read range and small form factor, each year billions of RFID tags are being deployed in retail, logistics, manufacturing, biomedical inventories, among many other applications. However, the performance of these RFID systems has not met expectations. This is because a tag's performance deteriorates significantly when mounted on or inside arbitrary materials. The tag antenna is optimized only for a given type of material at a certain location of placement, and detuning takes place when attached to or embedded in materials with dielectric properties outside the design range. Thereby, different customized tags may be needed for identifying objects even within the same class of products. This increases the overall cost of the system. Furthermore, conventional copper foil-based RFID tag antennas are prone to metal fatigue and wear, and cannot survive hostile environments where antennas could be deformed by external forces and failures occur. Therefore, it is essential to understand the interaction between the antenna and the material in the vicinity of the tag, and design general purpose RFID tag antennas possessing excellent electrical performance as well as robust mechanical structure. A particularly challenging application addressed here is designing passive RFID tag antennas for automotive tires. Tires are composed of multiple layers of rubber with different dielectric properties and thicknesses. Furthermore, metallic plies are embedded in the sidewalls and steel belts lie beneath the tread to enforce mechanical integrity. To complicate matters even more, a typical tire experiences a 10% stretching during the construction process. This dissertation focuses on intuitively understanding the interaction between the antenna and the material in the

  1. Frequency Reconfigurable Antenna for Deca-Band 5 G/LTE/WWAN Mobile Terminal Applications

    Science.gov (United States)

    Yang, Lingsheng; Cheng, Biyu; Jia, Hongting

    2018-04-01

    In this paper, a frequency reconfigurable antenna for 5 G/LTE/WWAN mobile terminal applications is presented. The proposed antenna consists of a radiation element which is folded on a dielectric cuboid. Four PIN diodes located on the antenna element are used for frequency reconfigration. By controlling the states of four PIN diodes with an 8-bit microcontroller, a broad band which can cover deca-band as LTE700/2300/2500, GSM850/900/1800/1900, UMTS 2100, WLAN2400 and the future 5 G or LTE3600 is obtained with a compacted size of 40×8×5mm3. The antenna gain, efficiency and radiation characteristics are also shown.

  2. High Performance Circularly Polarized Microstrip Antenna

    Science.gov (United States)

    Bondyopadhyay, Probir K. (Inventor)

    1997-01-01

    A microstrip antenna for radiating circularly polarized electromagnetic waves comprising a cluster array of at least four microstrip radiator elements, each of which is provided with dual orthogonal coplanar feeds in phase quadrature relation achieved by connection to an asymmetric T-junction power divider impedance notched at resonance. The dual fed circularly polarized reference element is positioned with its axis at a 45 deg angle with respect to the unit cell axis. The other three dual fed elements in the unit cell are positioned and fed with a coplanar feed structure with sequential rotation and phasing to enhance the axial ratio and impedance matching performance over a wide bandwidth. The centers of the radiator elements are disposed at the corners of a square with each side of a length d in the range of 0.7 to 0.9 times the free space wavelength of the antenna radiation and the radiator elements reside in a square unit cell area of sides equal to 2d and thereby permit the array to be used as a phased array antenna for electronic scanning and is realizable in a high temperature superconducting thin film material for high efficiency.

  3. Performance enhancement of implantable medical antenna using differential feed technique

    Directory of Open Access Journals (Sweden)

    Shankar Bhattacharjee

    2016-03-01

    Full Text Available The health care industry is continuously revolutionizing and advancing towards developing more efficient system suitable for human body. Today implantable devices have become a more interesting topic in health care services which primarily started with the pacemakers. Since then it is continuously evolving due to its non-invasive nature, instant monitoring and diagnosis, and periodic simulation. The main goal of these implantable devices is to efficiently monitor or inspect various ailments in the body and then transmits this to the server or base station. For proper communication between the implant and the base station, antenna design is of prime importance. In this paper MEMS based differentially fed dual band antenna has been proposed and can be used both in Medical Implant Communication Service (MICS band for transmission of data and industrial, scientific and medical (ISM band for wake-up purpose. The proposed antenna has been simulated for free space scenario and has been found to radiate in both MICS & ISM band with S11 of −17.62 dB and −14.31 dB respectively. Subsequently the antenna is inserted within a skin mimicking model with equivalent dielectric features and the results show variation in radiation characteristics between free space condition and within skin phantom. The design of the antenna has been optimized in such a way that minimum deviation occurs between the two conformal conditions. With the use of differential feeding technique performance of the antenna is quite enhanced in terms of various parameters when compared with single feed.

  4. Contemporary dielectric materials

    CERN Document Server

    Saravanan, R

    2016-01-01

    This book deals with experimental results of the physical characterization of several important, dielectric materials of great current interest. The experimental tools used for the analysis of these materials include X-ray diffraction, dielectric measurements, magnetic measurements using a vibrating sample magnetometer, optical measurements using a UV-Visible spectrometer etc.

  5. Dielectric Modulated FET (DMFET)

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Working Principle: Change in Dielectric constant due to immobilization of biomolecules in the nanogap cavity leads to change in effective gate capacitance and thus gate bias for FET. Working Principle: Change in Dielectric constant due to immobilization of biomolecules in the ...

  6. Thermal dielectric function

    International Nuclear Information System (INIS)

    Moneta, M.

    1999-01-01

    Thermal dielectric functions ε(k,ω) for homogeneous electron gas were determined and discussed. The ground state of the gas is described by the Fermi-Dirac momentum distribution. The low and high temperature limits of ε(k,ω) were related to the Lindhard dielectric function and to ε(k, omega) derived for Boltzmann and for classical momentum distributions, respectively. (author)

  7. Light in complex dielectrics

    NARCIS (Netherlands)

    Schuurmans, F.J.P.

    1999-01-01

    In this thesis the properties of light in complex dielectrics are described, with the two general topics of "modification of spontaneous emission" and "Anderson localization of light". The first part focuses on the spontaneous emission rate of an excited atom in a dielectric host with variable

  8. Antenna conditioning with insulating antenna tiles in Phaedrus-T

    International Nuclear Information System (INIS)

    Intrator, T.; Probert, P.; Doczy, M.; Diebold, D.; Brouchous, D.

    1994-01-01

    In the course of our Alfven wave heating and current drive experiments several different two and four strap antennas have been installed in Phaedrus-T. The motivation focusing the redesign of the antenna into a four strap design was to enable traveling wave phasing, and to reduce the k parallel ∼0 component of the wavenumber spectrum, and consequent edge power deposition. The latest modifications to the 4 strap antenna have dramatically improved its behavior, and enabled us to suppress its RF power induced impurity generation. The remaining gas reflux fueling is significant and is not local to the antenna

  9. Imaging performance of an isotropic negative dielectric constant slab.

    Science.gov (United States)

    Shivanand; Liu, Huikan; Webb, Kevin J

    2008-11-01

    The influence of material and thickness on the subwavelength imaging performance of a negative dielectric constant slab is studied. Resonance in the plane-wave transfer function produces a high spatial frequency ripple that could be useful in fabricating periodic structures. A cost function based on the plane-wave transfer function provides a useful metric to evaluate the planar slab lens performance, and using this, the optimal slab dielectric constant can be determined.

  10. Millimeter wave and terahertz dielectric properties of biological materials

    Science.gov (United States)

    Khan, Usman Ansar

    Broadband dielectric properties of materials can be employed to identify, detect, and characterize materials through their unique spectral signatures. In this study, millimeter wave, submillimeter wave, and terahertz dielectric properties of biological substances inclusive of liquids, solids, and powders were obtained using Dispersive Fourier Transform Spectroscopy (DFTS). Two broadband polarizing interferometers were constructed to test materials from 60 GHz to 1.2 THz. This is an extremely difficult portion of the frequency spectrum to obtain a material's dielectric properties since neither optical nor microwave-based techniques provide accurate data. The dielectric characteristics of liquids such as cyclohexane, chlorobenzene, benzene, ethanol, methanol, 1,4 dioxane, and 10% formalin were obtained using the liquid interferometer. Subsequently the solid interferometer was utilized to determine the dielectric properties of human breast tissues, which are fixed and preserved in 10% formalin. This joint collaboration with the Tufts New England Medical Center demonstrated a significant difference between the dielectric response of tumorous and non-tumorous breast tissues across the spectrum. Powders such as anthrax, flour, talc, corn starch, dry milk, and baking soda have been involved in a number of security threats and false alarms around the globe in the last decade. To be able to differentiate hoax attacks and serious security threats, the dielectric properties of common household powders were also examined using the solid interferometer to identify the powders' unique resonance peaks. A new sample preparation kit was designed to test the powder specimens. It was anticipated that millimeter wave and terahertz dielectric characterization will enable one to clearly distinguish one powder from the other; however most of the powders had relatively close dielectric responses and only Talc had a resonance signature recorded at 1.135 THz. Furthermore, due to

  11. Stretchable antenna for wearable electronics

    KAUST Repository

    Hussain, Muhammad Mustafa

    2017-04-13

    Various examples are provided for stretchable antennas that can be used for applications such as wearable electronics. In one example, a stretchable antenna includes a flexible support structure including a lateral spring section having a proximal end and at a distal end; a metallic antenna disposed on at least a portion of the lateral spring section, the metallic antenna extending along the lateral spring section from the proximal end; and a metallic feed coupled to the metallic antenna at the proximal end of the lateral spring section. In another example, a method includes patterning a polymer layer disposed on a substrate to define a lateral spring section; disposing a metal layer on at least a portion of the lateral spring section, the metal layer forming an antenna extending along the portion of the lateral spring section; and releasing the polymer layer and the metal layer from the substrate.

  12. A Compact UWB Diversity Antenna

    Directory of Open Access Journals (Sweden)

    Hui Zhao

    2014-01-01

    Full Text Available A compact printed ultrawideband (UWB diversity antenna with a size of 30 mm × 36 mm operating at a frequency range of 3.1–10.6 GHz is proposed. The antenna is composed of two semielliptical monopoles fed by two microstrip lines. Two semicircular slots, two rectangular slots, and one stub are introduced in the ground plane to adjust the impedance bandwidth of the antenna and improve the isolation between two feeding ports. The simulated and measured results show that impedance bandwidth of the proposed antenna can cover the whole UWB band with a good isolation of < −15 dB. The radiation patterns, peak antenna gain, and envelope correlation coefficient are also measured and discussed. The measured results show that the proposed antenna can be a good candidate for some portable MIMO/diversity UWB applications.

  13. Efficient Placement of Directional Antennas

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Feng [Los Alamos National Laboratory; Kasiviswanathan, Shiva [Los Alamos National Laboratory

    2010-09-20

    Directional antenna is an technology for the proliferation of wireless networks. In centralized wireless network, wireless devices communicate through base stations. Directed antennas are placed on base stations and form a backbone of communication. The communication between base stations and wireless devices can be interfered due to a large number of wireless device. Methodically positioning and orienting directed antennas can help to reduce the interference while saving energy. An integer linear programming is developed for siting and directing antennas on multiple base stations, and this formulation can be extended to model non-overlapping channels. Through the integer programming formulation, optimal antenna positions can be used to analyze the performance of directed antennas with different parameters like the number base stations and the number of non-overlapping channels.

  14. Design of optical antenna for solar energy collection

    International Nuclear Information System (INIS)

    Gallo, Michele; Mescia, Luciano; Losito, Onofrio; Bozzetti, Michele; Prudenzano, Francesco

    2012-01-01

    In this paper, an antenna array is designed in order to transform the thermal energy, provided by the Sun and re-emitted from the Earth, in electricity. The proposed antenna array is constituted by four square spirals of gold printed on a low cost dielectric substrate. A microstrip line, embedded into the substrate, is used to feed the array and to collect the thermal radiation. The dispersive behavior of gold at infrared frequencies has been taken into account through the Lorentz–Drude model. Simulations have been conducted in order to investigate the behavior of the antenna array illuminated by a circularly polarized plane wave with an amplitude chosen according to the Stefan–Boltzmann radiation law. An output current of about 3.8 μA has been simulated at 28.3 THz, i.e. at the frequency of the Earth emitted radiation. Moreover, these infrared antennas could be coupled with other components to obtain direct rectification of infrared radiation. As a consequence, these structures further optimized could be a promising alternative to the conventional photovoltaic solar cells.

  15. A revolutionary concept to improve the efficiency of IC antennas

    Energy Technology Data Exchange (ETDEWEB)

    Milanesio, D.; Maggiora, R. [Politecnico di Torino, Dipartimento di Elettronica e Telecomunicazioni (DET), Torino (Italy)

    2014-02-12

    The successful design of an Ion Cyclotron (IC) antenna mainly relies on the capability of coupling high power to the plasma (MW), feature that is currently reached by allowing rather high voltages (tens of kV) on the unavoidable unmatched part of the feeding lines. This requirement is often responsible of arcs along the transmission lines and other unwanted phenomena that considerably limit the usage of IC launchers. In this work, we suggest and describe a revolutionary approach based on high impedance surfaces, which allows to increase the antenna radiation efficiency and, hence, to highly reduce the imposed voltages to couple the same level of power to the plasma. High-impedance surfaces are periodic metallic structures (patches) displaced usually on top of a dielectric substrate and grounded by means of vertical posts usually embedded inside a dielectric, in a mushroom-like shape. In terms of working properties, high impedance surfaces are electrically thin in-phase reflectors, i.e. they present a high impedance, within a given frequency band, such that the image currents are in-phase with the currents of the antenna itself, thus determining a significant efficiency increase. While the usual design of a high impedance surface requires the presence of a dielectric layer, some alternative solutions can be realized in vacuum, taking advantage of double layers ofmetallic patches. After an introductory part on the properties of high impedance surfaces, this work documents both their design by means of numerical codes and their implementation on a scaled mock-up.

  16. 2D and 3D modeling of wave propagation in cold magnetized plasma near the Tore Supra ICRH antenna relying on the perfecly matched layer technique

    International Nuclear Information System (INIS)

    Jacquot, J; Colas, L; Clairet, F; Goniche, M; Hillairet, J; Lombard, G; Heuraux, S; Milanesio, D

    2013-01-01

    A novel method to simulate ion cyclotron wave coupling in the edge of a tokamak plasma with the finite element technique is presented. It is applied in the commercial software COMSOL Multiphysics. Its main features include the perfectly matched layer (PML) technique to emulate radiating boundary conditions beyond a critical cutoff layer for the fast wave (FW), full-wave propagation across the inhomogeneous cold peripheral plasma and a detailed description of the wave launcher geometry. The PML technique, while widely used in numerical simulations of wave propagation, has scarcely been used for magnetized plasmas, due to specificities of this gyrotropic material. A versatile PML formulation, valid for full dielectric tensors, is summarized and interpreted as wave propagation in an artificial medium. The behavior of this technique has been checked for plane waves on homogeneous plasmas. Wave reflection has been quantified and compared to analytical predictions. An incompatibility issue for adapting the PML for forward (FW) and backward (slow wave (SW)) propagating waves simultaneously has been evidenced. In a tokamak plasma, this critical issue is overcome by taking advantage of the inhomogeneous density profile to reflect the SW before it reaches the PML. The simulated coupling properties of a Tore Supra ion cyclotron resonance heating (ICRH) antenna have been compared to experimental values in a situation of good single-pass absorption. The necessary antenna elements to include in the geometry to recover the coupling properties obtained experimentally are also discussed. (paper)

  17. An Optimized Circuit in Plastic Meander Line Antenna for 2.45 GHz Applications

    Directory of Open Access Journals (Sweden)

    Farhat Majeed

    2016-01-01

    Full Text Available Researchers seek to design electrically small planar antennas for RFID applications. Using multiparameter optimization, various meander line antennas were designed for the lowest resonant frequency and maximum radiation efficiencies for a fixed grid size. One such design for highest radiation efficiency was optimized for microwave frequencies by including an impedance matching structure. The antenna was printed with silver ink on a plexiglass substrate using the circuit in plastic (CiP technique of embedded electrical components. The measured scattering parameter (S11 was −18.43 dB at resonance. The radiation efficiency of the antenna measured using simple and improved Wheeler cap method was 74.4/74.1%. The radiation pattern of electrically small CiP antenna was doughnut-shaped with main lobe magnitude of 0.453 dB and an angular width of 84.2° in elevation plane. The measured 10 dB fractional bandwidth of the antenna was 18.98%. The results are compared with silver/copper in air antennas optimized for achieving the highest radiation efficiency for a fixed grid size. Plastic antennas are viable at microwave frequencies.

  18. COMPACT DUAL-BAND INVERTED L SHAPED MONOPOLE ANTENNA FOR WLAN APPLICATIONS

    Directory of Open Access Journals (Sweden)

    K Sumathi

    2015-12-01

    Full Text Available A highly compact and an optimized design of an Inverted L shaped printed monopole antenna with a simple compact ground plane is proposed. To make the designed antenna suitable for implantation it is embedded in FR-4 substrate and is presented. The antenna is designed for dual-band operation at 2.4GHz and 5.2GHz. It is suitable for Wireless Local Area Network (WLAN applications with return loss (S11 < -10dB. The antenna has two different resonant current paths that support two resonances at 2.44GHz and 5.18GHz (forming an F-shaped structure. The size of the antenna is 32.5mm × 19.6mm × 1.6mm. The antenna design is simulated using the tool Advanced Design System (ADS 2014. This antenna design has good return loss and radiation characteristics in both the required frequency bands. The radiation pattern obtained from the proposed antenna is an Omni directional radiation pattern in the E and H plane over the frequency ranges 2.4GHz and 5.2GHz.

  19. Miniature Coplanar Implantable Antenna on Thin and Flexible Platform for Fully Wireless Intracranial Pressure Monitoring System

    Directory of Open Access Journals (Sweden)

    M. Waqas A. Khan

    2017-01-01

    Full Text Available Minimally invasive approach to intracranial pressure monitoring is desired for long-term diagnostics. The monitored pressure is transmitted outside the skull through an implant antenna. We present a new miniature (6 mm × 5 mm coplanar implant antenna and its integration on a sensor platform to establish a far-field data link for the sensor readout at distances of 0.5 to 1 meter. The implant antenna was developed using full-wave electromagnetic simulator and measured in a liquid phantom mimicking the dielectric properties of the human head. It achieved impedance reflection coefficient better than −10 dB from 2.38 GHz to 2.54 GHz which covers the targeted industrial, scientific, and medical band. Experiments resulted in an acceptable peak gain of approximately −23 dBi. The implant antenna was submerged in the liquid phantom and interfaced to a 0.5 mW voltage controlled oscillator. To verify the implant antenna performance as a part of the ICP monitoring system, we recorded the radiated signal strength using a spectrum analyzer. Using a half-wavelength dipole as the receiving antenna, we captured approximately −58.7 dBm signal at a distance of 1 m from the implant antenna which is well above for the reader with sensitivity of −80 dBm.

  20. New perspective on single-radiator multiple-port antennas for adaptive beamforming applications.

    Science.gov (United States)

    Byun, Gangil; Choo, Hosung

    2017-01-01

    One of the most challenging problems in recent antenna engineering fields is to achieve highly reliable beamforming capabilities in an extremely restricted space of small handheld devices. In this paper, we introduce a new perspective on single-radiator multiple-port (SRMP) antenna to alter the traditional approach of multiple-antenna arrays for improving beamforming performances with reduced aperture sizes. The major contribution of this paper is to demonstrate the beamforming capability of the SRMP antenna for use as an extremely miniaturized front-end component in more sophisticated beamforming applications. To examine the beamforming capability, the radiation properties and the array factor of the SRMP antenna are theoretically formulated for electromagnetic characterization and are used as complex weights to form adaptive array patterns. Then, its fundamental performance limits are rigorously explored through enumerative studies by varying the dielectric constant of the substrate, and field tests are conducted using a beamforming hardware to confirm the feasibility. The results demonstrate that the new perspective of the SRMP antenna allows for improved beamforming performances with the ability of maintaining consistently smaller aperture sizes compared to the traditional multiple-antenna arrays.

  1. New perspective on single-radiator multiple-port antennas for adaptive beamforming applications.

    Directory of Open Access Journals (Sweden)

    Gangil Byun

    Full Text Available One of the most challenging problems in recent antenna engineering fields is to achieve highly reliable beamforming capabilities in an extremely restricted space of small handheld devices. In this paper, we introduce a new perspective on single-radiator multiple-port (SRMP antenna to alter the traditional approach of multiple-antenna arrays for improving beamforming performances with reduced aperture sizes. The major contribution of this paper is to demonstrate the beamforming capability of the SRMP antenna for use as an extremely miniaturized front-end component in more sophisticated beamforming applications. To examine the beamforming capability, the radiation properties and the array factor of the SRMP antenna are theoretically formulated for electromagnetic characterization and are used as complex weights to form adaptive array patterns. Then, its fundamental performance limits are rigorously explored through enumerative studies by varying the dielectric constant of the substrate, and field tests are conducted using a beamforming hardware to confirm the feasibility. The results demonstrate that the new perspective of the SRMP antenna allows for improved beamforming performances with the ability of maintaining consistently smaller aperture sizes compared to the traditional multiple-antenna arrays.

  2. Dielectric and acoustical high frequency characterisation of PZT thin films

    International Nuclear Information System (INIS)

    Conde, Janine; Muralt, Paul

    2010-01-01

    Pb(Zr, Ti)O 3 (PZT) is an interesting material for bulk acoustic wave resonator applications due to its high electromechanical coupling constant, which would enable fabrication of large bandwidth frequency filters. The major challenge of the PZT solid solution system is to overcome mechanical losses generally observed in PZT ceramics. To increase the understanding of these losses in textured thin films, thin film bulk acoustic resonators (TFBAR's) based on PZT thin films with compositions either in the tetragonal region or at the morphotropic phase boundary and (111) or {100} textures were fabricated and studied up to 2 GHz. The dielectric and elastic materials coefficients were extracted from impedance measurements at the resonance frequency. The dispersion of the dielectric constant was obtained from impedance measurements up to 2 GHz. The films with varying compositions, textures and deposition methods (sol-gel or sputtering) were compared in terms of dielectric and acoustical properties.

  3. Dielectric and acoustical high frequency characterisation of PZT thin films

    Science.gov (United States)

    Conde, Janine; Muralt, Paul

    2010-02-01

    Pb(Zr, Ti)O3 (PZT) is an interesting material for bulk acoustic wave resonator applications due to its high electromechanical coupling constant, which would enable fabrication of large bandwidth frequency filters. The major challenge of the PZT solid solution system is to overcome mechanical losses generally observed in PZT ceramics. To increase the understanding of these losses in textured thin films, thin film bulk acoustic resonators (TFBAR's) based on PZT thin films with compositions either in the tetragonal region or at the morphotropic phase boundary and (111) or {100} textures were fabricated and studied up to 2 GHz. The dielectric and elastic materials coefficients were extracted from impedance measurements at the resonance frequency. The dispersion of the dielectric constant was obtained from impedance measurements up to 2 GHz. The films with varying compositions, textures and deposition methods (sol-gel or sputtering) were compared in terms of dielectric and acoustical properties.

  4. Improved Dielectric Films For Capacitors

    Science.gov (United States)

    Yen, Shiao-Ping S.; Lewis, Carol R.; Cygan, Peter J.; Jow, T. Richard

    1994-01-01

    Dielectric films made from blends of some commercially available high-dielectric-constant cyanoresins with each other and with cellulose triacetate (CTA) have both high dielectric constants and high breakdown strengths. Dielectric constants as high as 16.2. Films used to produce high-energy-density capacitors.

  5. Antenna Deployment for the Localization of Partial Discharges in Open-Air Substations

    Science.gov (United States)

    Robles, Guillermo; Fresno, José Manuel; Sánchez-Fernández, Matilde; Martínez-Tarifa, Juan Manuel

    2016-01-01

    Partial discharges are ionization processes inside or on the surface of dielectrics that can unveil insulation problems in electrical equipment. The charge accumulated is released under certain environmental and voltage conditions attacking the insulation both physically and chemically. The final consequence of a continuous occurrence of these events is the breakdown of the dielectric. The electron avalanche provokes a derivative of the electric field with respect to time, creating an electromagnetic impulse that can be detected with antennas. The localization of the source helps in the identification of the piece of equipment that has to be decommissioned. This can be done by deploying antennas and calculating the time difference of arrival (TDOA) of the electromagnetic pulses. However, small errors in this parameter can lead to great displacements of the calculated position of the source. Usually, four antennas are used to find the source but the array geometry has to be correctly deployed to have minimal errors in the localization. This paper demonstrates, by an analysis based on simulation and also experimentally, that the most common layouts are not always the best options and proposes a simple antenna layout to reduce the systematic error in the TDOA calculation due to the positions of the antennas in the array. PMID:27092501

  6. Ultra wide band antennas

    CERN Document Server

    Begaud, Xavier

    2013-01-01

    Ultra Wide Band Technology (UWB) has reached a level of maturity that allows us to offer wireless links with either high or low data rates. These wireless links are frequently associated with a location capability for which ultimate accuracy varies with the inverse of the frequency bandwidth. Using time or frequency domain waveforms, they are currently the subject of international standards facilitating their commercial implementation. Drawing up a complete state of the art, Ultra Wide Band Antennas is aimed at students, engineers and researchers and presents a summary of internationally recog

  7. Antennas on circular cylinders

    DEFF Research Database (Denmark)

    Knudsen, H. L.

    1959-01-01

    On the basis of the results obtained by Silver and Saunders [4] for the field radiated from an arbitrary slot in a perfectly conducting circular cylinder, expressions have been derived for the field radiated by a narrow helical slot, with an arbitrary aperture field distribution, in a circular...... antenna in a circular cylinder. By a procedure similar to the one used by Silver and Saunders, expressions have been derived for the field radiated from an arbitrary surface current distribution on a cylinder surface coaxial with a perfectly conducting cylinder. The cases where the space between the two...

  8. Ultra wideband antennas design, methodologies, and performance

    CERN Document Server

    Galvan-Tejada, Giselle M; Jardón Aguilar, Hildeberto

    2015-01-01

    Ultra Wideband Antennas: Design, Methodologies, and Performance presents the current state of the art of ultra wideband (UWB) antennas, from theory specific for these radiators to guidelines for the design of omnidirectional and directional UWB antennas. Offering a comprehensive overview of the latest UWB antenna research and development, this book:Discusses the developed theory for UWB antennas in frequency and time domainsDelivers a brief exposition of numerical methods for electromagnetics oriented to antennasDescribes solid-planar equivalen

  9. 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.

  10. Perturbation approach to design of circularly polarised microstrip antennas

    Science.gov (United States)

    Lo, Y. T.; Richards, W. F.

    1981-05-01

    One of the most interesting applications of microstrip antennas is its use for transmitting or receiving circularly polarized (CP) waves. A description is given of a simple but accurate method to determine the critical dimensions needed to produce circular polarization for nearly square and nearly circular microstrip antennas. Shen (1981) in connection with the determination of the proper dimensions of an elliptical patch CP microstrip antenna first expressed the modal field in terms of Mathieu functions. To avoid the complicated numerical computation of the Mathieu functions, he approximated these functions in terms of Bessel functions. It is pointed out that the computation of Mathieu functions, or their approximate expressions can be avoided altogether if a perturbation method is applied to find the resonant frequencies of the two orthogonal modes. The implementation of this approach is demonstrated.

  11. Spectrum of a linear antenna in a cold magnetized plasma

    International Nuclear Information System (INIS)

    Eldridge, O.; Kritz, A.H.

    1975-04-01

    The fields radiated by a linear antenna in a cold magnetized plasma are calculated. The principal results are expressed in the input impedance and power spectrum of the near field, expressed as a function of the wavenumber or index of refraction parallel to the field. For frequencies below the electron plasma frequency and above the lower hybrid frequency the spectrum shows a broad maximum for short parallel wavelengths. The parallel index of refraction at this maximum is approximately the ratio of free space wavelength to antenna length. A spectrum of this sort is required by the accessibility conditions for heating at the lower hybrid resonance from a wave launched in a region of lower density. The impedance of a short antenna in this region is capacitive and a few hundred ohms in magnitude. (U.S.)

  12. Slotted Circularly Polarized Microstrip Antenna for RFID Application

    Directory of Open Access Journals (Sweden)

    S. Kumar

    2017-12-01

    Full Text Available A single layer coaxial fed rectangular microstrip slotted antenna for circular polarization (CP is proposed for radio frequency identification (RFID application. Two triangular shaped slots and one rectangular slot along the diagonal axis of a square patch have been embedded. Due to slotted structure along the diagonal axis and less surface area, good quality of circular polarization has been obtained with the reduction in the size of microstrip antenna by 4.04 %. Circular polarization radiation performance has been studied by size and angle variation of diagonally slotted structures. The experimental result found for 10-dB return loss is 44 MHz with 10MHz of 3dB Axial Ratio (AR bandwidth respectively at the resonant frequency 910 MHz. The overall proposed antenna size including the ground plane is 80 mm x 80 mm x 4.572 mm.

  13. Miniaturization design and implementation of magnetic field coupled RFID antenna

    Science.gov (United States)

    Hu, Tiling

    2013-03-01

    The development of internet of things has brought new opportunities and challenges to the application of RFID tags. Moreover, the Miniaturization application trend of tags at present has become the mainstream of development. In this paper, the double-layer design is to reduce the size of HF antenna, and the magnetic null point of magnetic reconnection region between the RLC resonant circuit and the reader provides sufficient energy to the miniaturization of antenna. The calculated and experimental results show that the miniaturization of HF antennas can meet the reading and writing requirement of the international standard ISO/IEC14443 standard. The results of this paper may make a positive contribution to the applications of RFID technology.

  14. Dielectric materials for electrical engineering

    CERN Document Server

    Martinez-Vega, Juan

    2013-01-01

    Part 1 is particularly concerned with physical properties, electrical ageing and modeling with topics such as the physics of charged dielectric materials, conduction mechanisms, dielectric relaxation, space charge, electric ageing and life end models and dielectric experimental characterization. Part 2 concerns some applications specific to dielectric materials: insulating oils for transformers, electrorheological fluids, electrolytic capacitors, ionic membranes, photovoltaic conversion, dielectric thermal control coatings for geostationary satellites, plastics recycling and piezoelectric poly

  15. Cast dielectric composite linear accelerator

    Science.gov (United States)

    Sanders, David M [Livermore, CA; Sampayan, Stephen [Manteca, CA; Slenes, Kirk [Albuquerque, NM; Stoller, H M [Albuquerque, NM

    2009-11-10

    A linear accelerator having cast dielectric composite layers integrally formed with conductor electrodes in a solventless fabrication process, with the cast dielectric composite preferably having a nanoparticle filler in an organic polymer such as a thermosetting resin. By incorporating this cast dielectric composite the dielectric constant of critical insulating layers of the transmission lines of the accelerator are increased while simultaneously maintaining high dielectric strengths for the accelerator.

  16. Polarization insensitive metamaterial absorber based on E-shaped all-dielectric structure

    Directory of Open Access Journals (Sweden)

    Liyang Li

    2015-03-01

    Full Text Available In this paper, we designed a metamaterial absorber performed in microwave frequency band. This absorber is composed of E-shaped dielectrics which are arranged along different directions. The E-shaped all-dielectric structure is made of microwave ceramics with high permittivity and low loss. Within about 1 GHz frequency band, more than 86% absorption efficiency was observed for this metamaterial absorber. This absorber is polarization insensitive and is stable for incident angles. It is figured out that the polarization insensitive absorption is caused by the nearly located varied resonant modes which are excited by the E-shaped all-dielectric resonators with the same size but in the different direction. The E-shaped dielectric absorber contains intensive resonant points. Our research work paves a way for designing all-dielectric absorber.

  17. Antennas for light and plasmons

    NARCIS (Netherlands)

    Dikken, D.J.W.

    2015-01-01

    Antennas have been used for over a century as emitters, scatterers and receivers of electromagnetic waves. All wireless communication devices, such as radio, mobile phones and satellite communication are strongly dependent on the capability of an antenna to localize propagating electromagnetic waves

  18. Optically Controlled Phased Array Antenna

    National Research Council Canada - National Science Library

    Garafalo, David

    1998-01-01

    .... The antenna is a 3-foot by 9 foot phased array capable of a scan angle of 120 degrees. The antenna was designed to be conformal to the cargo door of a large aircraft and is designed to operate in the frequency range of 830 - 1400 MHz with a 30...

  19. Backfire antennas with dipole elements

    DEFF Research Database (Denmark)

    Nielsen, Erik Dragø; Pontoppidan, Knud

    1970-01-01

    A method is set up for a theoretical investigation of arbitrary backfire antennas based upon dipole structures. The mutual impedance between the dipole elements of the antenna is taken into account, and the field radiated due to a surface wave reflector of finite extent is determined by calculating...

  20. Slot-Coupled Barbel Antenna

    DEFF Research Database (Denmark)

    Jørgensen, Kasper Lüthje; Jakobsen, Kaj Bjarne

    2016-01-01

    A novel slot-coupled barbel antenna is designed and analyzed. A sensitivity analysis performed in order to improve the bandwidth, while the center frequency is kept constant.......A novel slot-coupled barbel antenna is designed and analyzed. A sensitivity analysis performed in order to improve the bandwidth, while the center frequency is kept constant....

  1. Dielectric loss against piezoelectric power harvesting

    International Nuclear Information System (INIS)

    Liang, Junrui; Shu-Hung Chung, Henry; Liao, Wei-Hsin

    2014-01-01

    Piezoelectricity is one of the most popular electromechanical transduction mechanisms for constructing kinetic energy harvesting systems. When a standard energy harvesting (SEH) interface circuit, i.e., bridge rectifier plus filter capacitor, is utilized for collecting piezoelectric power, the previous literature showed that the power conversion can be well predicted without much consideration for the effect of dielectric loss. Yet, as the conversion power gets higher by adopting power-boosting interface circuits, such as synchronized switch harvesting on inductor (SSHI), the neglect of dielectric loss might give rise to deviation in harvested power estimation. Given the continuous progress on power-boosting interface circuits, the role of dielectric loss in practical piezoelectric energy harvesting (PEH) systems should receive attention with better evaluation. Based on the integrated equivalent impedance network model, this fast track communication provides a comprehensive study on the susceptibility of harvested power in PEH systems under different conditions. It shows that, dielectric loss always counteracts piezoelectric power harvesting by causing charge leakage across piezoelectric capacitance. In particular, taking corresponding ideal lossless cases as references, the counteractive effect might be aggravated under one of the five conditions: larger dielectric loss tangent, lower vibration frequency, further away from resonance, weaker electromechanical coupling, or using power-boosting interface circuit. These relationships are valuable for the study of PEH systems, as they not only help explain the role of dielectric loss in piezoelectric power harvesting, but also add complementary insights for material, structure, excitation, and circuit considerations towards holistic evaluation and design for practical PEH systems. (fast track communications)

  2. Compact Wideband and Low-Profile Antenna Mountable on Large Metallic Surfaces

    DEFF Research Database (Denmark)

    Zhang, Shuai; Pedersen, Gert F.

    2017-01-01

    This paper proposes a compact wideband and low-profile antenna mountable on large metallic surfaces. Six rows of coupled microstrip resonators with different lengths are printed on a Teflon block. The lengths of the microstrip resonators in different rows are gradually reduced along the end-fire...

  3. Non-foster impedance matching sensitivity of electrically small electric and magnetic spherical dipole antennas

    DEFF Research Database (Denmark)

    Yoon, Ick-Jae; Christensen, S.; Zhurbenko, Vitaliy

    2016-01-01

    The impedance bandwidth (BW) improvement property of a self-resonant folded spherical helix electric dipole and a spherical split ring (SSR) magnetic dipole is compared when a negative reactance element is loaded on the parasitic resonator of the antennas. They have the same electrical size of ka...

  4. Optics of dielectric microstructures

    DEFF Research Database (Denmark)

    Søndergaard, Thomas

    2002-01-01

    From the work carried out within the ph.d. project two topics have been selected for this thesis, namely emission of radiation by sources in dielectric microstructures, and planar photonic crystal waveguides. The work done within the first topic, emission of radiation by sources in dielectric...... microstructures, will be presented in the part I of this thesis consisting of the chapters 2-5. An introductions is given in chapter 2. In part I three methods are presented for calculating spontaneous and classical emission from sources in dielectric microstructures. The first method presented in chapter 3...... is based on the Fermi Golden Rule, and spontaneous emission from emitters in a passive dielectric microstructure is calculated by summing over the emission into each electromagnetic mode of the radiation field. This method is applied to investigate spontaneous emission in a two-dimensional photonic crystal...

  5. The Study and Implementation of Electrically Small Printed Antennas for an Integrated Transceiver Design

    Energy Technology Data Exchange (ETDEWEB)

    Speer, Pete [Univ. of Kansas, Lawrence, KS (United States)

    2009-04-28

    This work focuses on the design and evaluation of the inverted-F, meandering-monopole, and loop antenna geometries. These printed antennas are studied with the goal of identifying which is suitable for use in a miniaturized transceiver design and which has the ability to provide superior performance using minimal Printed Circuit Board (PCB) space. As a result, the main objective is to characterize tradeoffs and identify which antenna provides the best compromise among volume, bandwidth and efficiency. For experimentation purposes, three types of meandering-monopole antenna are examined resulting in five total antennas for the study. The performance of each antenna under study is evaluated based upon return loss, operational bandwidth, and radiation pattern characteristics. For our purposes, return loss is measured using the S11-port reflection coefficient which helps to characterize how well the small antenna is able to be efficiently fed. Operational bandwidth is measured as the frequency range over which the antenna maintains 2:1 Voltage Standing Wave Ratio (VSWR) or equivalently has 10-dB return loss. Ansoft High Frequency Structure Simulator (HFSS) is used to simulate expected resonant frequency, bandwidth, VSWR, and radiation pattern characteristics. Ansoft HFSS simulation is used to provide a good starting point for antenna design before actual prototype are built using an LPKF automated router. Simulated results are compared with actual measurements to highlight any differences and help demonstrate the effects of antenna miniaturization. Radiation characteristics are measured illustrating how each antenna is affected by the influence of a non-ideal ground plane. The antenna with outstanding performance is further evaluated to determine its maximum range of communication. Each designs range performance is evaluated using a pair of transceivers to demonstrate round-trip communication. This research is intended to provide a knowledge base which will help

  6. Antenna Design Considerations for the Advanced Extravehicular Mobility Unit

    Science.gov (United States)

    Bakula, Casey J.; Theofylaktos, Onoufrios

    2015-01-01

    NASA is designing an Advanced Extravehicular Mobility Unit (AEMU)to support future manned missions beyond low-Earth orbit (LEO). A key component of the AEMU is the communications assembly that allows for the wireless transfer of voice, video, and suit telemetry. The Extravehicular Mobility Unit (EMU) currently used on the International Space Station (ISS) contains a radio system with a single omni-directional resonant cavity antenna operating slightly above 400 MHz capable of transmitting and receiving data at a rate of about 125 kbps. Recent wireless communications architectures are calling for the inclusion of commercial wireless standards such as 802.11 that operate in higher frequency bands at much higher data rates. The current AEMU radio design supports a 400 MHz band for low-rate mission-critical data and a high-rate band based on commercial wireless local area network (WLAN) technology to support video, communication with non-extravehicular activity (EVA) assets such as wireless sensors and robotic assistants, and a redundant path for mission-critical EVA data. This paper recommends the replacement of the existing EMU antenna with a new antenna that maintains the performance characteristics of the current antenna but with lower weight and volume footprints. NASA has funded several firms to develop such an antenna over the past few years, and the most promising designs are variations on the basic patch antenna. This antenna technology at UHF is considered by the authors to be mature and ready for infusion into NASA AEMU technology development programs.

  7. A broadband helical saline water liquid antenna for wearable systems

    Science.gov (United States)

    Li, Gaosheng; Huang, Yi; Gao, Gui; Yang, Cheng; Lu, Zhonghao; Liu, Wei

    2018-04-01

    A broadband helical liquid antenna made of saline water is proposed. A transparent hollow support is employed to fabricate the antenna. The rotation structure is fabricated with a thin flexible tube. The saline water with a concentration of 3.5% can be injected into or be extracted out from the tube to change the quantity of the solution. Thus, the tunability of the radiation pattern could be realised by applying the fluidity of the liquid. The radiation feature of the liquid antenna is compared with that of a metal one, and fairly good agreement has been achieved. Furthermore, three statements of the radiation performance corresponding to the ratio of the diameter to the wavelength of the helical saline water antenna have been proposed. It has been found that the resonance frequency increases when the length of the feeding probe or the radius of the vertical part of the liquid decreases. The fractional bandwidth can reach over 20% with a total height of 185 mm at 1.80 GHz. The measured results indicate reasonable approximation to the simulated. The characteristics of the liquid antenna make it a good candidate for various wireless applications, especially the wearable systems.

  8. Energy tunneling through narrow waveguide channel and design of small antennas

    Directory of Open Access Journals (Sweden)

    Mitrović Miranda

    2011-01-01

    Full Text Available In this paper we investigate the conditions for energy tunneling through narrow channel obtained by reducing the height of rectangular waveguide. Tunneling of the energy occurs at the frequency for which the effective dielectric permittivity of the channel becomes equal to zero, so it can be treated as an ENZ (epsilon-near-zero metamaterial. We investigated how geometry of the channel and dielectric permittivity affect the transmission coefficient and field density in the channel. Adding slots in the channel, which are placed orthogonally to the wave propagation, we designed a small antenna with directivity of 5.44 dBi at the frequency of 3 GHz.

  9. Unidirectional emission in an all-dielectric nanoantenna.

    Science.gov (United States)

    Feng, Tianhua; Zhang, Wei; Liang, Zixian; Xu, Yi

    2018-03-28

    All-dielectric nanoantennas are a promising alternative to plasmonic optical antennas for engineering light emission because of their low-loss nature in the optical spectrum. Nevertheless, it is still challenging to manipulate directional light emission with subwavelength all-dielectric nanoantennas. Here, we propose and numerically demonstrate that a hollow silicon nanodisk can serve as a versatile antenna for directing and enhancing the emission from either an electric or magnetic dipole emitter. When primarily coupled to both electric and magnetic dipole modes of a nanoantenna, broadband nearly-unidirectional emission can be realized by the interference of two modes, which can be spectrally tuned via the geometric parameters in an easy way. More importantly, the emission directions for the magnetic and electric dipole emitters are shown as opposite to each other through control of the phase difference between the induced magnetic and electric dipole modes of the antenna. Meanwhile, the Purcell factors can be enhanced by more than one order of magnitude and high quantum efficiencies can be maintained at the visible spectrum for both kinds of dipole emitters. We further show that these unidirectional emission phenomena can withstand small disorder effects of in-plane dipole orientation and location. Our study provides a simple yet versatile platform that can shape the emission of both magnetic and electric dipole emitters.

  10. Excitation and absorption of electromagnetic waves in helicon discharges by plasma immersed antennas

    International Nuclear Information System (INIS)

    Cho, S.

    1998-01-01

    Excitation and absorption of electromagnetic waves are numerically studied for helicon discharges driven by antennas immersed in the plasma. The Maxwell equations are reduced to a set of ordinary differential equations, which are solved for radially inhomogeneous plasmas by using the shooting method. Numerical results show that the plasma resistance is much larger and its peaks due to eigenmode resonance appear at higher densities for the immersed antenna case than for the case of the antenna located outside the plasma under otherwise same conditions. It is also found that the m=-1 mode can be excited in the nonuniform plasma with an inner antenna, while it can be hardly excited when the plasma is driven by an outer antenna. In addition, the fast wave approximation neglecting the electron inertia is discussed. (author)

  11. Passive wireless structural health monitoring sensor made with a flexible planar dipole antenna

    International Nuclear Information System (INIS)

    Jang, Sang-Dong; Kim, Jaehwan

    2012-01-01

    Cheap and efficient wireless sensors have been widely studied by electronics and communication technology development. In this paper, a flexible planar dipole antenna based passive wireless strain sensor has been investigated. The planar dipole antenna is designed for X band and made on a flexible polymer substrate using a conventional photolithography process. The fabricated dipole antenna is attached to a nonmetallic cantilever beam and monitors its bending strain. Mechanical strain and load impedance of the dipole antenna can change its resonance frequency, return loss and reflected signal. The return loss and reflected signals of the dipole antenna sensor are characterized by using a network analyzer. The strain sensitivity of the sensor is proportional to the return loss variation with the bending strain of the cantilever beam. The magnitude of reflected signals increases as the bending strain increases. (technical note)

  12. A tunable plasmonic nano-antenna based on metal–graphene double-nanorods

    Science.gov (United States)

    Dong, Zhewei; Sun, Chen; Si, Jiangnan; Deng, Xiaoxu

    2018-05-01

    A tunable plasmonic antenna based on metal–graphene nanostructures is proposed in the mid-infrared region, composed of two identical gold nanorods placed on separated graphene sheets. The unidirectional side scattering of the plasmonic antenna achieved by the constructive and destructive interference of the localized surface plasmon resonances (LSPR) of the nanorods is investigated using finite-difference time-domain solutions and is theoretically analyzed based on a two point dipole model. The scattering directivity peak of the plasmonic antenna is red-shifted linearly with increasing refractive index of the environment. The scattering direction from the plasmonic antenna is switched actively by tuning the LSPRs of the nanorods with the Fermi energies of the separated graphene sheets. The refractive index sensitivity and active tunable scattering direction of the plasmonic antenna provides a promising application to manipulate light at the nanoscale in the fields of bio-sensing and optoelectronic devices.

  13. Modified Sierpinski Gasket Patch Antenna for UMTS and 2.4/5.2 WLAN

    Directory of Open Access Journals (Sweden)

    Y. E. Ali

    2013-05-01

    Full Text Available A modified Sierpinski Gasket fractal antenna for multiband application is proposed in this paper. The modified ground plane and the microstrip feed are used to obtain the wider bandwidth at the resonance frequency. The antenna is designed and printed on two layers FR-4 substrate (ϵr=4.4 and h=1.6 mm to cover the UMTS and 2.4/5.2 WLAN. The radiation pattern of the proposed antenna is similar to an omnidirectional. The proposed antenna has maximum gain of 1.88, 1.6, 4.31 dB at 2, 2.4, 5.2 GHz, respectively The properties of the antenna such as return losses, radiation pattern, input resistance and gain are determined via numerical CST Microwave Studio 2010 software.

  14. All-dielectric band stop filter at terahertz frequencies

    Science.gov (United States)

    Yin, Shan; Chen, Lin

    2018-01-01

    We design all-dielectric band stop filters with silicon subwavelength rod and block arrays at terahertz frequencies. Supporting magnetic dipole resonances originated from the Mia resonance, the all-dielectric filters can modulate the working band by simply varying the structural geometry, while eliminating the ohmic loss induced by the traditional metallic metamaterials and uninvolved with the complicated mechanism. The nature of the resonance in the silicon arrays is clarified, which is attributed to the destructive interference between the directly transmitted waves and the waves emitted from the magnetic dipole resonances, and the resonance frequency is determined by the dielectric structure. By particularly designing the geometrical parameters, the profile of the transmission spectrum can be tailored, and the step-like band edge can be obtained. The all-dielectric filters can realize 93% modulation of the transmission within 0.04 THz, and maintain the bandwidth of 0.05 THz. This work provides a method to develop THz functional devices, such as filters, switches and sensors.

  15. Novel Miniaturized Octaband Antenna for LTE Smart Handset Applications

    Directory of Open Access Journals (Sweden)

    Haixia Liu

    2015-01-01

    Full Text Available A novel octaband LTE mobile phone antenna is presented, which has a compact size with the overall dimension of 35 mm × 9 mm × 3 mm. The miniaturized octaband antenna is implemented by a simple prototype of three parts which include a folded monopole as feeding element, main radiator element, and parasitic radiator element. The main and parasitic radiator elements are excited by the folded monopole feeding element coupling and shorting to the handset ground plane. A wide bandwidth in low-frequency bands covering from 747 MHz to 960 MHz (LTE Band13/GSM850/GSM900 is contributed by both main and parasitic radiator elements. In addition, the folded monopole is designed to resonate at 2530 MHz, and the coupling between the feeding element and main radiator element is designed to resonate at 1840 MHz. Subsequently, the wide bandwidth in high-frequency bands covering from 1710 MHz to 2690 MHz (DCS1800/PCS1900/WCDMA2100/LTE2300/LTE2500 is contributed by both structures. The antenna has the total efficiency up to 30% in low bands and up to 75% in high bands, respectively. At the same time, the proposed miniaturized octaband LTE mobile phone antenna is fabricated and tested to verify the design.

  16. Testing quantised inertia on emdrives with dielectrics

    Science.gov (United States)

    McCulloch, M. E.

    2017-05-01

    Truncated-cone-shaped cavities with microwaves resonating within them (emdrives) move slightly towards their narrow ends, in contradiction to standard physics. This effect has been predicted by a model called quantised inertia (MiHsC) which assumes that the inertia of the microwaves is caused by Unruh radiation, more of which is allowed at the wide end. Therefore, photons going towards the wide end gain inertia, and to conserve momentum the cavity must move towards its narrow end, as observed. A previous analysis with quantised inertia predicted a controversial photon acceleration, which is shown here to be unnecessary. The previous analysis also mispredicted the thrust in those emdrives with dielectrics. It is shown here that having a dielectric at one end of the cavity is equivalent to widening the cavity at that end, and when dielectrics are considered, then quantised inertia predicts these results as well as the others, except for Shawyer's first test where the thrust is predicted to be the right size but in the wrong direction. As a further test, quantised inertia predicts that an emdrive's thrust can be enhanced by using a dielectric at the wide end.

  17. Resonant halide perovskite nanoparticles

    Science.gov (United States)

    Tiguntseva, Ekaterina Y.; Ishteev, Arthur R.; Komissarenko, Filipp E.; Zuev, Dmitry A.; Ushakova, Elena V.; Milichko, Valentin A.; Nesterov-Mueller, Alexander; Makarov, Sergey V.; Zakhidov, Anvar A.

    2017-09-01

    The hybrid halide perovskites is a prospective material for fabrication of cost-effective optical devices. Unique perovskites properties are used for solar cells and different photonic applications. Recently, perovskite-based nanophotonics has emerged. Here, we consider perovskite like a high-refractive index dielectric material, which can be considered to be a basis for nanoparticles fabrication with Mie resonances. As a result, we fabricate and study resonant perovskite nanoparticles with different sizes. We reveal, that spherical nanoparticles show enhanced photoluminescence signal. The achieved results lay a cornerstone in the field of novel types of organic-inorganic nanophotonics devices with optical properties improved by Mie resonances.

  18. Response of spherical gravitational wave antenna modes to high-energy cosmic ray particles

    International Nuclear Information System (INIS)

    Jr, R M Marinho; Magalhaes, N S; Aguiar, O D; Frajuca, C

    2002-01-01

    High-energy cosmic ray particles are expected to be a significant source of noise in resonant mass gravitational wave detectors close to the quantum limit. The spherical, fourth generation antennas have been designed to attain such a limit. In this work we will show how the energy of a cosmic ray particle interacting with such an antenna is distributed over its eigenmodes. We will then make some comments on the relevant consequences of such a distribution for gravitational wave detection

  19. Response of spherical gravitational wave antenna modes to high-energy cosmic ray particles

    CERN Document Server

    Marinho, R M; Aguiar, O D; Frajuca, C

    2002-01-01

    High-energy cosmic ray particles are expected to be a significant source of noise in resonant mass gravitational wave detectors close to the quantum limit. The spherical, fourth generation antennas have been designed to attain such a limit. In this work we will show how the energy of a cosmic ray particle interacting with such an antenna is distributed over its eigenmodes. We will then make some comments on the relevant consequences of such a distribution for gravitational wave detection.

  20. Metamaterial antennas: the most successful metamaterial technology?

    DEFF Research Database (Denmark)

    Breinbjerg, Olav

    2015-01-01

    The Thomson Reuters Web of Science™ lists more than 1500 journal articles related to metamaterial antennas from 2001 to 2015; this paper overviews some major objectives of such antennas.......The Thomson Reuters Web of Science™ lists more than 1500 journal articles related to metamaterial antennas from 2001 to 2015; this paper overviews some major objectives of such antennas....