Accurate evaluation of mutual coupling for array calibration

Calibration of receiving antenna arrays generally yields a square coupling matrix characterizing the array response. It is demonstrated in this paper that in the presence of strong structure scattering, the array response is better described by a non-square coupling matrix. Therefore, the calibration procedure must account for these new matrix dimensions. The different approaches providing accurate non-square coupling matrices are described, and important guidelines are given for the determination of the coupling matrix dimensions for obtaining the best performance.