Optimal synthesis of thinned arrays using biogeography based optimization

Abstract

Thinning of large arrays in order to produce low side lobes is a diffcult task. Conventional gradient methods often stuck in local minima and hence are not capable of obtaining optimum solutions. As a result, global optimization methods are required to thin large antenna arrays. In this paper, a global evolutionary method, Biogeography Based Optimization (BBO) is introduced as a new tool for thinning large linear and planar antenna arrays of uniformly excited isotropic antennas. The aim is to synthesize linear arrays so as to yield the maximum relative sidelobe level equal to or below a desired level while also keeping the percentage of thinning equal to or above the desired level. The results obtained by BBO are compared with the previous published results of Genetic Algorithm (GA), Ant Colony Optimization (ACO), Immunity Genetic Algorithm (IGA) and Binary Particle Swarm Optimization (BPSO).