Null placements in non-uniformly excited beam steered linear array using particle swarm optimization

Abstract

In this paper, a novel method for null placements in beam steered linear array with unequal excitation amplitude and uniform inter-element spacing has been presented. The proposed method has been developed using Taylor one parameter distribution for linear array and particle swarm optimization (PSO). The beam steering has been achieved by maintaining a constant phase difference between two consecutive elements of the array. In order to place nulls in the desired direction excitation amplitude perturbation method using PSO has been considered. Search space of PSO has been defined using Taylor one parameter distribution for linear array. Within the defined search space PSO with the null placement objective. The proposed method has been tested for both single and wide null objectives. As example 12 elements linear array has been considered, for both single and wide null placement objective. Results show that, null level in the desired directions lies within 89% to 100% of desired null level of -60 dB, which in turn proves the effectiveness of the proposed method.