Mutual Coupling Evaluation in Microstrip Arrays by Characteristic Modes

n this work, the Theory of Characteristic Modes in conjunction with Spectral Domain Moment Method is used for evaluation of the mutual coupling phenomenon between microstrip patch elements. Computed results are found to be in excellent agreement with calculated results obtained by standard MoM with subdomain basis functions. Because a small number of characteristic modes are necessary to yield a good approximation of the induced current on patches, the proposed method dramatically reduce the number of unknowns and the corresponding computational effort in the MoM solution of the problem.