Research on near field pattern effects

This report is a summary of the research accomplishments achieved during the present contract period. Our main objective has been to develop an efficient numerical solution to compute the near as well as far field radiation patterns for an antenna mounted on a prolate spheroid. Note that the prolate spheroid will be used in the future to simulate the fuselage of a general aircraft. The uniform Geometrical Theory of Diffraction solutions which were developed previously were used to analyze the radiation from the prolate spheroid; however they require one to identify the appropriate geodesic paths. These geodesic paths indicate the flow of energy as it propagates around the spheroid. Using a cone perturbation model, an efficient numerical solution for the geodesic paths and the associated radiation patterns has been obtained. This solution was also extended to analyze the scattering from a finite flate plate which was illuminated by energy propagating around the spheroid. However, the flate plate can not be any closer than a few wavelengths to the spheroid. This shortcoming will be corrected in the near future.