volume | PIER Journals

Abstract

A new, approximate, uniform geometrical theory of diffraction (UTD) based ray solutions are developed for describing the high frequency electromagnetic (EM) wave radiation/coupling mechanisms for antennas on or near a junction between two different thin planar slabs on ground plane. The present solution is obtained by extending the normal incidence solution in order to treat the more general case of skew (or oblique) incidence (three-dimensional 3-D). Plane wave (for oblique or skew incidence) and spherical wave illumination are all considered in this work. Unlike most previous works, which analyze the plane wave scattering by such structures via the Wiener-Hopf (W-H) or Maliuzhinets (MZ) methods, the present development can also treat problems of the radiation by and coupling between antennas near or on finite material coatings on large metallic platforms. In addition, the present solution does not contain the complicated split functions of the W-H solutions nor the complex MZ functions. Unlike the latter methods based on approximate boundary conditions, the present solutions, which are developed via a heuristic spectral synthesis approach, recover the proper local plane wave Fresnel reflection and transmission coefficients and surface wave constants of the material slabs. There is a very good agreement, with less than ± 1 dB differences when the numerical results based on the presented UTD solution for a material junction are compared with that of the MZ solution.

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Prof. Titipong Lertwiriyaprapa

Dr. Prabhakar H. Pathak

Professor John Volakis