Mutual coupling effects correction in microstrip arrays for direction-of-arrival (DOA) estimation

The presence of mutual coupling severely degrades the performance of an adaptive array. A simple method based on obtaining an N×N coupling matrix, C, to compensate for the coupling effects in direction-of-arrival (DOA) estimation algorithms is presented. It is based on the theory of characteristic modes in conjunction with an element-by-element analysis of finite arrays. As a small number of characteristic modes are needed to yield a good approximation of induced currents, the method significantly reduces the computational effort in calculating the unknowns. Its application to the MUSIC algorithm results in good and efficient performance.