A study on variation of side lobe level of optimized uniformly excited time-modulated linear antenna arrays

Abstract

In this paper, the variation of side lobe level (SLL) of ‘optimized uniformly excited time-modulated linear antenna array’ (OUE-TMLAA) with different number of antenna elements is presented. To realize the optimized array patterns of the arrays, sideband levels (SBLs) is suppressed to below −30 dB and the increase on first null beam width (FNBW) is restricted within 35% of that of the ‘uniformly excited conventional linear antenna arrays’ (UE-CLAAs) while the peak SLL is reduced as low as possible. A differential evolution (DE) based optimization method is employed where only the on-time sequence of the antenna elements are considered as the optimization parameter vectors. By taking the antenna arrays of wide range of number of antenna elements, starting from 10 to 500 and using the average results of 20 trials of each OUE-TMLAA, a representative plot of the variation of average SLLs with the number of antenna elements is presented.