A simple model applied to the analysis of E-plane and H-plane mutual coupling between microstrip antennas

The study of mutual coupling between microstrip patches is useful to design arrays of this kind of antennas, where the spacing between elements are less than a wavelength. Coupling between a patch and its neighbours must be computed to find the impedance matrix relating currents and voltages in the array. Microstrip patches are represented by magnetic current lines using the cavity model (CM). The theoretical model presented is useful to predict the coupling levels between microstrip antennas, and it has been developed for two basic configurations (E-plane and H-plane). The method shows enough accuracy when the substrate height is small in terms of wavelengths, as required by CM. The required computing time is very little in comparison with other methods (full-wave models, extended CM, reaction principle with exact Green´s functions), methods that don´t ensure total accuracy