Characterizing an Array's Mutual Coupling via a Time-Modulated Array Technique

In this letter, we model the mutual coupling of a time-modulated array (TMA) and investigate methods for characterizing the mutual coupling using complex-quantity and magnitude-only measurements. We show that the TMA-based rotating electric vector approach is effective when using magnitude-only measurements. We discuss the selection of an appropriate preset angle and investigate the characterization of the error in the coupling coefficient caused by the preset angle error. Our experiments validate the proposed method and the associated theory.