Numerical optimisation of compressive array feed networks

Abstract

Compressive antenna arrays reduce the number of beamforming controls by taking a limited number of weighted combinations of the element signals. A compressive array sidelobe level (SLL)-minimisation algorithm, inspired by coherence-optimisation algorithms, is presented. Optimised compressive arrays are shown to obtain better SLLs than existing weighted thinned arrays and completely overlapped subarrays. The design of a compressive array with arbitrary sidelobe requirements shows that increasing the number of elements for a given number of beamforming controls improves array performance over a conventional array. A compressive array with a hard null is proposed to suppress interference before sampling. Where beamforming controls are the main cost drivers, the proposed approach promises to increase array performance without a significant increase in cost.