Comment on ´compensate for the coupled radiation patterns of compact transmitting antenna arrays´

In a recent study by Niow et al., it has been shown that an effective method for mutual coupling compensation in antenna arrays can be based on mutual impedances between antenna elements and the active element input impedance. Consequently, Niow et al. have derived an equation for compensated excitation voltages, which allows the radiation pattern of an antenna array to be predicted accurately using the principle of pattern multiplication. In the current comment, the authors show that the effectiveness of those equations depends on the level of mutual coupling between radiating elements, and becomes lower for strong mutual coupling. The authors explain the reason for this deficiency and a corrected form of the equations was proposed for the compensated excitation voltages.