The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Powen Hsu - One of the best experts on this subject based on the ideXlab platform.
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on the size reduction of planar yagi uda antenna using Parabolic Reflector
Asia-Pacific Microwave Conference, 2015Co-Authors: Huanchu Huang, Powen HsuAbstract:A planar Yagi-Uda antenna using the Parabolic Reflector is designed and compared to that of using the conventional straight Reflector. Both antennas are designed to have the same performance. Simulation results show that the Parabolic Reflector design can reduce the occupied antenna area by about 29.4% as compared to that of the straight Reflector design, while the antenna directivity and efficiency are retained at 7.16 dBi and −0.70 dB, respectively. Thus the Parabolic Reflector design is suitable for designing compact directive antennas in the low-profile devices.
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a planar yagi uda antenna with a meandered driven dipole and a concave Parabolic Reflector
Asia-Pacific Microwave Conference, 2010Co-Authors: Huanchu Huang, Powen HsuAbstract:A planar Yagi-Uda antenna with a single director, a meandered driven dipole, and a concave Parabolic Reflector on a thin dielectric substrate is proposed. Through this design, the high directivity of 7.3 dBi, front-to-back ratio of 14.7 dB, cross-polarization level of −39.1 dB, bandwidth of 5.8%, and the radiation efficiency of 87.5%, which is better than −1 dBi in terms of the 3D average gain, can be achieved. Besides, the area of this antenna is much smaller than that of the previously proposed one by about 78%. Therefore, the proposed antenna is suitable for the GPS (Global Positioning System) application in mobile devices whose volumes are usually not sufficient for embedded antennas with a good RHCP (right hand circular polarization) AR (axial ratio) values and not enough angular coverage of the designed AR values.
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a simple planar high directivity yagi uda antenna with a concave Parabolic Reflector
International Workshop on Antenna Technology, 2010Co-Authors: Huanchu Huang, Powen HsuAbstract:A simple planar Yagi-Uda antenna with a single director and a concave Parabolic Reflector on a thin dielectric substrate is proposed. Through the innovative design, the simple Yagi-Uda antenna can achieve the high directivity of 9.0 dBi, front-to-back ratio of 14.5 dB, cross-polarization level of −38.7 dB, bandwidth of 6.0%, and the radiation efficiency of 85.1%, i.e., better than −1 dBi in terms of the 3D average gain. This proposed antenna is especially suitable for the mobile devices with GPS functions.
Yu Jian Cheng - One of the best experts on this subject based on the ideXlab platform.
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generating and 2 d steering large depth of field beam by leaky wave antenna array with a modified Parabolic Reflector
IEEE Transactions on Antennas and Propagation, 2020Co-Authors: Yu Jian ChengAbstract:A millimeter-wave substrate-integrated waveguide (SIW) antenna with the ability of generating 2-D steerable large depth-of-field beam is presented in this article. First, a transverse antenna topology feeding with the series- and the parallel-network is employed to generate the limited-diffractive beam with large depth of field to overcome the problem that the conventional radial generator cannot steer its beam electronically. The proposed antenna is achieved by combining a modulated leaky-wave slot array antenna with a modified multibeam SIW Parabolic Reflector. The modulated leaky-wave slot array with stepped-width is designed to able to steer the limited-diffractive beam in the horizontal dimension with the frequency, which validates the frequency scanning feasibility of the limited-diffractive beam. Then a modified SIW Parabolic Reflector with matching loads is used to feed the modulated leaky-wave SIW slot array antenna to generate multiple limited-diffractive beams in the vertical dimension. A large depth of field of about $43\lambda _{0}$ is achieved of the central limited-diffractive beam. The measurements are in good agreement with the simulated results.
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millimeter wave substrate integrated waveguide multibeam antenna based on the Parabolic Reflector principle
IEEE Transactions on Antennas and Propagation, 2008Co-Authors: Yu Jian Cheng, Wei HongAbstract:A novel substrate integrated waveguide (SIW) multibeam antenna based on the Parabolic Reflector principle is proposed and implemented at 37.5 GHz, which takes the advantages of low loss, low profile, high gain, and mass producible. A prototype of the proposed antenna with seven input ports generating a corresponding number of output beams is fabricated in a standard PCB process. The measurements are in good agreement with the simulations, and the results demonstrate that this type of printed multibeam antenna is a good choice for communications applications where mobility and high gain are simultaneously required.
M H A J Herben - One of the best experts on this subject based on the ideXlab platform.
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the scan performance of the fresnel zone plate antenna a comparison with the Parabolic Reflector antenna
Microwave and Optical Technology Letters, 1993Co-Authors: L C J Baggen, C J J Jeronimus, M H A J HerbenAbstract:Using Kirchhoffs diffraction theory, scalar field analyses of two off-axis focused antenna systems, the Fresnel-zone plate antenna (FZPA) and Parabolic Reflector antenna, are presented. Expressions which describe the gain patterns of both antennas are derived and used to examine the scan properties of the two systems and to reveal and discuss similarities and differences between them. The results of the analysis give good insight into future applications of the FZPA as a multibeam antenna. © 1993 John Wiley & Sons, Inc.
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vectorial far field analysis of the fresnel zone plate antenna a comparison with the Parabolic Reflector antenna
Microwave and Optical Technology Letters, 1992Co-Authors: L Leyten, M H A J HerbenAbstract:An analysis of the radiation properties of the Fresnel-zone plate antenna (FZPA) and the Parabolic Reflector antenna (PRA) is presented using the Kirchhoff diffraction theory. Expressions are derived for the vectorial far-field radiation patterns of both antennas. Some computed co- and cross-polar patterns are shown. The most important differences between the radiation properties of the FZPA and PRA are revealed and discussed. The results of the analysis give good insight into future applications of the FZPA.
I P Theron - One of the best experts on this subject based on the ideXlab platform.
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l band feed horn and orthogonal mode transducer for the kat 7 radio telescope
IEEE Transactions on Antennas and Propagation, 2011Co-Authors: Robert Lehmensiek, I P TheronAbstract:The design, simulation and measured performance of a broad bandwidth L-band wide flare angle corrugated conical horn and its orthogonal mode transducer are presented. The feed horn is used on prime focus Parabolic Reflector antennas of a seven-element interferometer, which is part of the Karoo Array Telescope project. The horn was designed to maximize the sensitivity of the radio telescope over a frequency band of 47.6% relative bandwidth. The orthogonal mode transducer design has low insertion and transmission losses and good isolation, and because of its compact size requires a very small cryogenic cooling system.
Y Rahmatsamii - One of the best experts on this subject based on the ideXlab platform.
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design and measurement of low profile metal only offset Parabolic stepped Reflector antenna for emerging cubesats
International Symposium on Antennas and Propagation, 2020Co-Authors: Vignesh Manohar, Y RahmatsamiiAbstract:The needs for low-profile high gain antennas have significantly evolved in the recent past due to the possibilities of advanced space missions with CubeSats. In this paper, we describe the development of a low-profile, offset, metal-only stepped Parabolic Reflector antenna which can be integrated with the CubeSat form factor with minimal deployment complexity. The Reflector surface consists of multiple Parabolic sections that are confocal and thus provide a collimated beam in the far-field. As a representative example, an offset stepped Reflector with a diameter of 20 cm and a profile height of 7.9 mm at 19 GHz is designed, fabricated and measured. The performance of this stepped Reflector is comparable to that of an ideal Parabolic Reflector, however with a significant reduction in profile height.
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synthesis and analysis of low profile metal only stepped Parabolic Reflector antenna
IEEE Transactions on Antennas and Propagation, 2018Co-Authors: Vignesh Manohar, Joshua M. Kovitz, Y RahmatsamiiAbstract:This paper describes an intuitive approach for synthesizing metal-only, low-profile, high-gain stepped Reflector antennas that can aid emerging technologies in the areas of communications and remote sensing. The required Reflector aperture is synthesized using a family of confocal Parabolic sections, each of which scatters in phase to provide a focused beam in the far field. The Parabolic sections provide a distinct advantage over the conventional Fresnel zone plate (FZP) antenna, since the radiation is inherently unidirectional. Furthermore, the metal-only structure avoids the need for dielectric characterization, which is essential for reflectarrays. Using this technique, it is possible to achieve depths of the order of one wavelength while ensuring high efficiencies. Starting from a symmetric stepped Reflector synthesis, two distinct approaches to synthesize offset stepped Reflectors are explored in this paper. We highlight several interesting tradeoffs between electromagnetic performance and mechanical complexity that arise for each of these approaches. A thorough analysis of the frequency performance of stepped Parabolic Reflectors is also presented. Comprehensive simulations using both physical optics and multilevel fast multipole method validate our theoretical predictions. The formulations presented in this paper are especially relevant at mmWave frequencies and beyond, which has attracted significant interest for modern technologies.
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random surface error effects on offset cylindrical Reflector antennas
IEEE Transactions on Antennas and Propagation, 2003Co-Authors: S Sinton, Y RahmatsamiiAbstract:The focus of this paper is to characterize the average power pattern of an offset cylindrical Parabolic Reflector antenna subject to random surface errors. A novel computational method is developed for studying the random surface error effects on the boresight gain loss and the sidelobe levels of the average power pattern. The particular antenna dimensions used for this study are similar to the specifications for the second generation precipitation radar (PR-2) mission. In keeping with the requirements in the PR-2 mission, both the Ku and Ka frequency bands are considered. Random surface error effects are also studied for different edge taper levels. In addition to analysis of a Reflector with uniform random surface errors, a nonuniform surface error case is presented in this study. This is an important consideration for evaluating the suitability of large deployable membrane Reflector antennas for the PR-2 mission.
