Calculation of the H-Plane Aperture Distribution and Far Field Pattern for a Metal Plate Loaded Horn

摘要

This note describes the results of a mathematical analysis of the aperture distribution of a horn which has been loaded with a conducting plate. The purpose of the plate is to improve the H-plane far field pattern of the horn and hence the angular resolution of a passive millimetre wave imager which uses a horn fed antenna. The calculation is based on the Fresnel-Kirchoff diffraction formula and account is taken of multiple reflections within the horn and from the plate. The resulting H-plane aperture distribution is far from uniform but has a sharp far field pattern. The E-plane distribution remains unchanged by the presence of the plate. Great Britain. (RH)