Geometry and Weight Optimization for Minimizing Sidelobes in Wideband Planar Arrays

Arrays are often analyzed using a narrowband or single-frequency assumption for simplicity. However, for arrays used in wideband applications this simplification is not valid. In this paper, a sidelobe-minimizing method is presented that efficiently determines the optimal weights given a specified beamwidth for wideband planar arrays of elements scanned to broadside. This method can be executed significantly faster than optimal wideband weighting methods developed previously. This speedup in computation time allows for simultaneous weight-geometry optimization. Optimal array geometries are determined using the Particle Swarm Optimization (PSO) algorithm in conjunction with the optimal weights in order to minimize sidelobe levels in wideband arrays. Results (optimal positions, weights and sidelobe levels) are presented for wideband arrays of 4-7 elements.