Daniel S. Katz^{*}, Allen Taflove

Department of Electrical Engineering and Computer Science

The Technological Institute

Northwestern University

Evanston, IL 60208

This paper considers computational modeling of the patterns of electromagnetic wave radiation in systems involving horn antennas, in both two and three dimensions. Using the Finite-Difference Time-Domain (FD-TD) method, simple horn antennas are modeled and the antenna patterns are shown to correspond to experimental and analytic results. The antennas are modeled in two and three dimensions, and the three-dimensional model includes the model of a coaxial feed.

In two dimensions, FD-TD is used to model a horn feeding a parabolic antenna, and again the results are shown to agree with results in the literature. Further extensions of this modeling scheme are also discussed. One interesting application is the direct FD-TD modeling of a compact range. Here a system consisting of a horn antenna feeding an electrically-large ( ~100 wavelength ) shaped reflector is modeled in a single 2-D FD-TD grid run on the Cray-2. Initial FD-TD computer results for contour maps of the field magnitude and phase versus spatial position in the model of the compact range are presented.