A wide-angle scanning optical antenna

The design of a modified Rinehart metal dome antenna with a dielectric ring lens at the output edge is discussed. This antenna provides wide-angle scanning of a narrow beam. The dome shape, which provides perfect focus in the plane of scan, is determined by solving an integral equation. The dielectric lens focuses in the plane perpendicular to the plane scan, and results in a much smaller antenna than if an -plane horn were fitted to a conventional Rinehart dome. A design procedure for minimizing phase errors and mismatch losses is discussed. The construction of an experimental model which provides a by beam at 40 GHz is described. Pattern and gain data for the 26.5 to 40 GHz band are included and show excellent performance.