摘要:

A numerical scheme effective in dealing with a class of two-dimensional open waveguide problems is summarized in this paper. It involves initially a decomposition of a given problem into several elementary waveguide discontinuity problems so that characterization of each individual one is known analytically in the spectral domain independent of its excitation. Governing equations for spectral components in the coupling regions connecting adjacent waveguide discontinuities are then derived and solved numerically. The asymptotic behavior of unknown spectral components usually can be derived from related edge conditions and used effectively to improve the convergence of the solution.

ISSN:0272-6343    

DOI:10.1080/02726348108915128

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

ABSTRACT The use of computer graphics as an integral part of the solution process in electromagnetic computer modeling is as yet relatively undeveloped. In this paper we consider now and in what ways computer graphics might be employee in EM modeling. First, we summarize plotting quantities, variables, and formats that can be used. Then, we provide a selection of representative examples to illustrate various graphics applications. It is our nope to stimulate increased attention to an area that we believe can contribute significantly to the more effective use of computer modeling.

ISSN:0272-6343    

DOI:10.1080/02726348108915129

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

This paper reviews the basic analytical and numerical characteristics of the Jacobi-Bessel series applied to the determination of the Fresnel and Fraunhofer fields radiated by planar apertures and reflector antennas. Only the final formulations are presented here and the reader is referred to the published papers by the authors for specific details. Many useful representative numerical results are generated to demonstrate the applicability of the technique.

ISSN:0272-6343    

DOI:10.1080/02726348108915130

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Using the terminology of the Wiener-Hopf technique, the Weinstein's diffraction function is defined as the “plus” part G+(s,p) of the Green's functionThis function plays an important role in the solutions of parallel–plate diffracti on problems, roughly equivalent to the Fresnel function in the half-plane diffraction problem. A table of G+(s,p) is given in Weinstein's book,The Theory of Diffraction and the Factorization Method(Golen Press, 1969), and a more extensive five-figure table was later published in Russian by E. I. Nefedov. Both tables are calculated from an approximate version of G+(s,p). In the present paper, we provide a s e t of numerical tables forexactWeinstein's diffraction functions, together with a summary of relevant formulas and a discussion of numerical computations.

ISSN:0272-6343    

DOI:10.1080/02726348108915131

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The most general form of the Singularity Expansion Method (SEM) representation of the transient scattering response of a finite extent object allows considerable freedom of choice as to the time at which one begins to include the sum of residue contributions into the transient response--i.e., the “turn-on” time. The issue of the chosen form of the coupling coefficient used in computing these residue constituents relates intimately with the choice of turn-on time. The practical range of choices for turn-on time is considerably more restricted than the theoretical one. In this paper limitations on turn-on time are established in terms of the maximum geometric extent of the object and of the geometric extent of the object projected in the direction of propagation of the incident wave. These limitations are dictated in order to insure the convergence of the SEM residue series, and are, in general, different for the Class 1 and for the Class 2 coupling coefficient. It is further argued that the convergence of the series is more likely to be influenced by numerical error, if one attempts to apply the series too close to these bounds of turn-on time. This numerical sensitivity phenomenon is interpreted in terms of the sensitivity computation of the coupling coefficient integrals to pole error and supported with a numerical example. An optimum time origin location is determined to allow the earliest possible turn-on time for all possible incident angles and is found to be the center of the minimum sphere which circumscribes the object.

ISSN:0272-6343    

DOI:10.1080/02726348108915132

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A method of moments procedure is presented for solving the integral equation satisfied by the electrostatic charge distribution over arbitrary planar domains. This procedure is based on a representation of such domains as a collection of quadrilateral subdomains, using the Gordon-Hall and Zienkiewicz-Phillips subdivision techniques. All integrals are effectively evaluated over triangles, and rely on an expression for the potential at a point due to a constant charge distribution over a triangular domain.

ISSN:0272-6343    

DOI:10.1080/02726348108915133

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor