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1. |
Scattering from Microstrip Patch Antennas Using Subdomain Basis Functions |
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Electromagnetics,
Volume 14,
Issue 1,
1994,
Page 1-18
D. G. Shively,
M. C. Bailey,
C. R. Cockrell,
M. D. Deshpande,
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摘要:
The scattering properties of microstrip patch antennas are examined with a spectral domain moment method approach. The Galerkin solution presented uses subdomain basis functions to model the current distribution on the patch so that a space varying surface resistance on the patch may be included. The subdomain approach is also used to model circular and triangular microstrip patches by approximating the patch boundary with a rectangular grid. Both calculated and measured results are presented for a few representative cases.
ISSN:0272-6343
DOI:10.1080/02726349408908366
出版商:Taylor & Francis Group
年代:1994
数据来源: Taylor
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2. |
Radar Cross Section Computation of Microstrip Patches |
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Electromagnetics,
Volume 14,
Issue 1,
1994,
Page 19-32
S. A. Bokhari,
J. R. Mosig,
F. E. Gardiol,
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PDF (768KB)
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摘要:
The paper presents a method for the computation of the radar cross section of microstrip patches. The approach is based on a combination of ideas derived from the mixed potential integral equation formulation for microstrip antennas, fast convolution algorithms and the biconjugate gradient iterative method. All operations are kept at a vector level and this renders the method capable of handling a large number of unknowns. Numerical results for a rectangular and a circular patch have been compared with measured results available in literature and a good agreement has been observed. Advantages and limitations are discussed.
ISSN:0272-6343
DOI:10.1080/02726349408908367
出版商:Taylor & Francis Group
年代:1994
数据来源: Taylor
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3. |
RCS Computation of Coax-Loaded Microstrip Patch Antennas of Arbitrary Shape |
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Electromagnetics,
Volume 14,
Issue 1,
1994,
Page 33-62
KrzysztofA. Michalski,
Chung-IG. Hsu,
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PDF (633KB)
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摘要:
A space-domain mixed-potential integral equation approach is applied in conjunction with the method of moments to compute the radar cross-section (RCS) of coax-loaded microslrip patch antennas having arbitrary or irregular shapes. The effects of Lhe substrate—which may be electrically thick and may consist of any number of planar, possibly uniaxially anisotropic dielectric layers, backed by a ground plane—are rigorously incorporated in the analysis by means of the vector and scalar potential Green's functions. The latter are expressed in terms of the voltages and currents on transmission line analogs of the layered medium, associated with TM and TE partial fields. The current distribution on the microstrip patch is approximated using vector basis functions defined over triangular elements and the coax probe current is expanded in terms of piecewise-lincar subdomain basis functions. A simple probe-to-patch attachment mode, compatible with the triangular element model of the microstrip patch, is used to enforce current continuity at the junction, and the coax aperture is modeled by a magnetic enrrent frill. The far zone fields are found by the stationary phase method, and are expressed in terms of the Fourier-transformed basis functions and the transmission line voltages and currents evaluated at the stationary phase point value of the transverse wavenumber. Computed RCS results are presented for several loaded and unloaded microstrip patch antennas of various shapes and are shown to be in agreement with published measured data and with computed results obtained by specialized techniques, which—unlike the method presented here—are not easily extendable to arbitrary shapes.
ISSN:0272-6343
DOI:10.1080/02726349408908368
出版商:Taylor & Francis Group
年代:1994
数据来源: Taylor
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4. |
Electromagnetic Scattering from Microstrip Patch Antennas and Spirals Residing in a Cavity |
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Electromagnetics,
Volume 14,
Issue 1,
1994,
Page 63-85
J. L. Volakis,
J. Gong,
A. Alexanian,
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PDF (541KB)
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摘要:
A new hybrid method is reviewed for the analysis of the scattering by conformal antennas and arrays comprised of circular or rectangular elements. In addition, calculations for cavity-backed spiral antennas are given. The method employs a finite element formulation within the cavity and the boundary integral (exact boundary condition) for terminating the mesh. By virtue of the finite element discretization, the method has no restrictions on the geometry and composition of the cavity or its termination. Furthermore, because of the convolutional nature of the boundary integral and the inherent sparseness of the finite element matrix, the storage requirement is kept very low at0(n). These unique features of the method have already been exploited in other scattering applications and have permitted the analysis of largo–size structures with remarkable efficiency. In this paper, we describe the method’s formulation and implementation for circular and rectangular patch antennas in the presence of lumped loads and resistive sheets/cards. Many computational examples for rectangular and circular patch configurations are presented which demonstrate the method’s versatility, modeling capability and accuracy.
ISSN:0272-6343
DOI:10.1080/02726349408908369
出版商:Taylor & Francis Group
年代:1994
数据来源: Taylor
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5. |
Radiation and Scattering of a Square Archimedean Spiral Antenna Using FDTD |
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Electromagnetics,
Volume 14,
Issue 1,
1994,
Page 87-97
ChristopherW. Penney,
RaymondJ. Luebbers,
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PDF (478KB)
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摘要:
A Finite-Difference, Time-Domain (FDTD) analysis of a square Archimedean spiral antenna is performed to calculate antenna gain and scattering patterns. The spiral is mounted in a large, conducting ground plane and is backed by an air-filled or absorber-filled cavity. The effects of resistive sheets placed over the spiral are also evaluated for both radiation and scattering. Total-field FDTD calculations are used to compute the gain patterns, while a specially-modified scattered-field approach for aperture antennas in infinite ground planes is used for the scattering results. Comparisons are made with calculations done with a Finite Element method and excellent results are obtained.
ISSN:0272-6343
DOI:10.1080/02726349408908370
出版商:Taylor & Francis Group
年代:1994
数据来源: Taylor
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6. |
Theoretical and Experimental Determination of the Polarimetric Antenna Radar Cross Section |
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Electromagnetics,
Volume 14,
Issue 1,
1994,
Page 99-117
Eberhardt Heidrich,
Werner Wiesbeck,
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PDF (385KB)
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摘要:
The total radar cross section (RCS) of antennas is the vector sum of structural and antenna mode scattering. These RCS contributions can be described completely by their polarimetric scattering matrices. The paper introduces a new polarimetric network description for three and four port antennas. The total scattering matrix is separated into the individual contributions with a new measurement procedure, based on complex load variations. Two waveguide and two planar antennas are chosen for demonstration and verification. By load variation the antenna mode scattering can be manipulated in phase and amplitude. It can especially be steered to compensate for the structural and aperture contributions. The possibilities for RCS minimization under polarimetric aspects are shown to be limited in bandwidth, polarization and aspect angle.
ISSN:0272-6343
DOI:10.1080/02726349408908371
出版商:Taylor & Francis Group
年代:1994
数据来源: Taylor
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