Analysis of superconducting patch antennas using the spectral domain method
- Hokkaido Univ., Sapporo (Japan). Faculty of Engineering
In this paper, the authors analyze electrical small HTS (High-Tc Superconductors) patch antennas using the modified spectral domain moment method (SDMM). Although it is assumed that a patch and a ground plane are perfect electric conductors (PECs) in the conventional SDMM, they can compute the performance of not only HTS patch antennas but also patch antennas with a conducting loss, by exchanging the boundary conditions on the conductors for {Epsilon}{sub t} = Z{sub s}J{sub s}, where {Epsilon}{sub t} is the tangential {Epsilon} field, Z{sub s} is surface impedance on the conductors, and J{sub s} is surface impedance on the conductors, and J{sub s} is surface current density. Z{sub s} of HTS is determined by using the ``three-fluid model`` in the analysis. This paper presents the numerical results for a 2.8GHz HTS patch antenna with 12mm length and 1.5mm width, on the grounded dielectric substrate with thickness d = 0.5mm, {epsilon}{sub r} = 25 and tan {delta} = 0. As the result, one can see that efficiency of the HTS patch is improved, for example, 3.8 times at T = 0(K) and 2.9 times at T = 77(K) improvement are obtained from the analysis. As regards the input impedance when a patch is proved, the peak at the resonance of the Cu patch is much smaller than the PEC patch, because the resonance is weaker as a conducting loss is larger, Therefore, the peak of the HTS patch is larger than that of the Cu patch, and is smaller than that of the PEC patch. This tendency is dependent on Z{sub s} of HTS, that is, this peak is larger as a real part of Z{sub s} is smaller. The authors also show that the resonance frequency of the HTS patch is shifted as temperature is changing. There are conducting losses, a dielectric loss and surface wave losses as factors degrading radiation efficiency. They examine the loss mechanism of the HTS patch for the various substrate thickness, d.
- OSTI ID:
- 61246
- Report Number(s):
- CONF-940142-; ISBN 0-8194-1451-4; TRN: IM9526%%27
- Resource Relation:
- Conference: OE/LASE `94: conference on optics, electro-optics, and laser applications in science and engineering, Los Angeles, CA (United States), 22-29 Jan 1994; Other Information: PBD: 1994; Related Information: Is Part Of High {Tc} microwave superconductors and applications. Volume 2156; Hammond, R.B.; Withers, R.S. [eds.]; PB: 235 p.
- Country of Publication:
- United States
- Language:
- English
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