Synthesis of planar array radiation patterns as applied in the design of a space-fed lens antenna

Abstract

In the course of developing a point design of a bootlace lens antenna for a space-based radar, a versatile radiation pattern synthesis technique capable of simultaneously controlling the mainlobe shape as well as the sidelobe level has been developed for planar phased arrays. Utilizing certain minimax properties of a power functional, the method does not rely on the shape of special mathematical functions and is therefore applicable to a broader class of arrays. After a brief description of its principle, which is based on the extension of an earlier procedure developed for linear arrays by the same author, the technique was applied to the synthesis of the radiation pattern of a feed array of the space-fed lens antenna. The objective is to obtain as closely as possible a two-dimensional gaussian illumination function on the lens surface, while at the same time maintaining a low sidelobe level to minimize the feed loss due to spill-over. Results of this synthesis are presented and discussed.