Side lobe level suppression in randomly spaced linear array using genetic Algorithm

This paper presents synthesis of randomly spaced linear array (RSLA) with reduced side lobe level (SLL). Excitation amplitude is assumed to be constant across the array elements and the inter-element spacing is kept in the specified range. A global optimization algorithm (Genetic Algorithm) is proposed to compute the optimum arrangement of inter-element spacings corresponding to lowest possible peak SLL. To validate the effectiveness of the proposed method, an example of RSLA with 24 elements is analysed and numerical results are compared with those using uniform elements' spacing and other published approaches for similar design scenario. Additionally, the effect of mutual coupling among array elements on the performance of RSLA is investigated through an extensive EM simulation study using commercial HFSS software by considering M-shaped patch radiating elements. The EM simulation results for the proposed RSLA having M-shaped equally-excited patch elements with mutual coupling among array elements are compared with those of without mutual coupling, numerical and published results.