EN
Circular and concentric circular antenna array patterns are synthesized to generate array factors with minimum side-lobe level and high directivity. The comprehensive learning differential search algorithm is used for synthesizing a one-and a three-ring circular and concentric circular antenna array with thirty elements. This synthesis is done by finding the optimum inter-element spacing of rings, phases and/or positions that give optimum side lobe level. The computational results show that side lobe level is reduced significantly in non-uniform case for concentric in comparison with a single ring.