Multiple loop sidelobe canceller

Abstract

A sidelobe canceller using only a widely spaced auxiliary array can lose performance for multiple jammers located at angles corresponding to the grating lobe structure. The degradation is independent of the number of control loops used. A closely spaced auxiliary array cannot resolve and process closely spaced jammers but is less susceptible to grating lobe occurrences. Its performance can degrade for closely spaced jammers while the widely spaced array has the resolution capability required. A dual array approach comprised of both widely and closely spaced subarrays was simulated and tested. Each subarray automatically compensated for the deficiencies of the other. The computer simulations predicted the precise nature and locations of these geometrical conditions when the system was tested. Auxiliary channel preprocessing can successfully be used with the dual array approach to simultaneously minimize the differential level problem for multiple jammers. Without preprocessing of the auxiliary array, little, if any cancellation may be achieved against weaker jammers.