GTD analysis of reflector antennas with general rim shapes: Near and far field solutions
Abstract
A combined technique of aperture integration and geometrical theory of diffraction (GTD) for analyzing paraboloidal reflectors with general rim shape is presented. Aperture integration is used to compute the main beam and near sidelobes; GTD is used to compute the wide angle sidelobes and backlobes. Two efficient techniques are employed to carry out the aperture integration. One is the overlapping subaperture method; the other is the rotating grid method. The use of overlapping, rectangular subapertures with triangular distributions permits a piecewise linear approximation to the overall aperture distribution of the reflector and consequently gives excellent accuracy with relatively few aperture field samples. For far field computations a rotating grid method is used such that the pattern is calculated in the plane perpendicular to the rotated axis and thus reduces to a one dimensional integration; this provides greatly improved efficiency over the many two dimensional integrations that would otherwise be required.
 Publication:

Ph.D. Thesis
 Pub Date:
 1980
 Bibcode:
 1980PhDT........69L
 Keywords:

 Antennas;
 Apertures;
 Diffraction Patterns;
 Far Fields;
 Near Fields;
 Parabolic Reflectors;
 Reflector Antennas;
 Antenna Design;
 Sidelobes;
 Wave Diffraction;
 Communications and Radar