A general-purpose interactive antenna analysis program

An interactive computer program (GAP) has been developed to solve a wide class of antenna problems on an IBM 360/65 computer, including the analysis of antenna performance and generation of antenna surfaces, in problems where the interior fields can be treated by geometric optics methods. The ray-tracing methods used account for the polarization, energy density, pathlength (phase) and wavefront curvature information associated with each ray, so that the resulting surface currents and aperture field distributions are accurate within the basic geometric optics approximation. Up to six surfaces (regular or deformed) may be used in the ray-trace analysis. Rays which miss reflectors and/or the aperture plane, or are blocked, are accounted for. Far-field patterns are computed from either "wavefront" approximations in the aperture plane or current distributions on the final reflector surface using standard integral representations. The user is given a wide choice of options for input of fields and surfaces and outputs both of far-field and intermediate fields and currents.