Adaptive nulling with multiple-beam antennas

Abstract

Some of the more prominent features of an Applebaum-Howells type adaptive nulling processor when used in conjunction with a multiple-beam antenna operating over the earth field of view at synchronous altitude are discussed. Incorporation of this scheme with a multiple-beam antenna allows for the use of a large filled aperture in order to obtain pattern shaping capabilities over a limited field of view while keeping the number of antenna output ports at a tractable number. It also leads to a partial decoupling of the adaptive feedback loops, a property which can be exploited to provide significant improvements in the dynamic performance of the control system. Three techniques for accomplishing this improved dynamic performance particularly applicable to multiple-beam antennas are considered.