Element Mutual Coupling Effect in a Wideband Planar Aperiodic Sparse Phased Array

This paper presents our study on a planar wideband aperiodic sparse phased array and the effect of element mutual coupling. The planar aperiodic sparse array in a circular disk with a diameter of 10 lambda(0) was optimized by using covariance matrix adaption evolutionary strategy (CMA-ES) together with Danzer tiling to generate the peak SLL(Side Lobe Level) of array factor less than -13 dB without the main beam steered and -9.5 dB with the main beam steered to 6W away from the broadside in a band ranging from f(0) to 10f(0). Then, the array using the rectangular patch antenna as the element has been simulated by using CST Microwave Studio to study the effect of mutual coupling when the elements are separated by lambda(0)/2 at f(0). Basically, the peak gain degrades a little bit, while peak SLL has large degradation in some specific directions, resulting from the mutual coupling between the array elements.