A NULLING PERFORMANCE COMPARISON BETWEEN A SINGLE-AND MULTIPLE-APERTURE MULTIPLE-BEAM ANTENNA

Discussed in this paper is the nulling performance of a single- and a multiple-aperture multiple-beam antenna (MBA). A linearly constrained minimum power algorithm incorporating both main beam and derivative co nstraints is formulated and simulated. The nulling resolution of the m ultiple-aperture MBA is shown to be superior to that of the single-ape rture MBA. In addition, a method for illuminating a region in space wi th constant gain while simultaneously nulling interfering signals with in a fractional single element beamwidth of this constant gain region is illustrated. A flat gain pattern is achieved by spacing derivative constraints over the spatial region where the desired signals are know n to be transmitting. Derivative constraints are particularly useful w hen the precise directions of arrival for the desired signals are not available to the beamformer.