Decoupling Methods for the Mutual Coupling Effect in Antenna Arrays: A Review

Hon Tat Hui

Abstract

Mutual coupling is a common problem in the applications of antenna arrays. It significantly affects the operation of almost all types of antenna arrays. Over the past years, there have been many different kinds of methods suggested to decouple (or to compensate for) the mutual coupling effect in antenna arrays. The effectiveness of these methods varied and depended upon the types of antenna arrays being considered and the applications in which the antenna arrays were used. In this paper, a brief review of the decoupling methods for the mutual coupling effect in antenna arrays is presented. These include patented and non-patented methods. The methods are grouped under seven categories for antenna arrays in communications and four categories for antenna arrays in magnetic resonance imaging (MRI). The various methods will be first briefly described and their operation principles will be explained. Then some comments on their scopes of application and their comparisons or relations to other methods will be given. The problems associated with these methods will also be analysed. This is the first review on this topic and we believe that it helps to give an overview of the decoupling methods which have been so far proposed in the literature. We also believe that this review will help clarify some main differences and relations between the various decoupling methods and provide some information for future research on the problem of mutual coupling.

Keywords: Mutual coupling, decoupling method, compensation method, communication, magnetic resonance imaging (MRI), antenna array, MRI phased array, surface coil array, mutual impedance, receiving mutual impedance