Mutual coupling compensation of compact antenna array for direction-of-arrivals estimations

Mutual coupling is well known as an undesirable effect as it degrades the performance of most array signal processing algorithm. Such undesirable effect becomes significant when the antenna element spacing becomes small, which is the case for compact antenna array. Throughout the years, extensive studies from signal processing and communication society have been conducted to compensate such undesirable effect. In this paper, a new method for the determination of receiving mutual impedances of omni-directional antenna elements is proposed. The new method is able to compensate such undesirable effect for compact array. Numerical examples of using the new method for the determinations receiving mutual impedances for some monopole arrays are given, which aims to show the differences between the old and new methods. DOA estimation examples with better accuracies demonstrate the superior mutual coupling characterization performance of the new receiving mutual impedance determination method over existing methods.