THINNED ARRAYS USING PATTERN SEARCH ALGORITHMS

Abstract

In this paper, pattern search (PS) algorithms are introduced as a new tool for array thinning. It is shown that by selection of a fitness function which controls more than one parameter of the array pattern, and also by proper setting of weight factors in fitness function, one can achieve very good results. The method is tested on linear arrays of isotropic and non-isotropic elements and is shown to be useful in both cases. Mainlobe scanning to different angles is also tested and the results are success. In all cases studied in this paper, relative sidelobe level (SLL) is less than -20 dB with only small increase in mainlobe beamwidth compared to the case of a uniform array. Results of PS optimization are compared in two cases, which their starting points of optimization are different from each other. There is also a comparison made between results of array thinning using Genetic Algorithm (GA) and PS, and PS is shown to be a fast and reliable algorithm to be used in array thinning problem.