ANALYSIS OF THE COUPLING BETWEEN DEGENERATE MODES OF ENCLOSED RECTANGULAR MICROSTRIP PATCHES

Coupling between the two degenerate modes of a square patch, caused by a square corner cutout, is examined. The effect of a corner cutout on the coupling between modes of two adjacent patches is also discussed. The problem is formulated using an integral equation in the spectral domain, and solved with the Method of Moments. Two types of basis func tions were used; full domain functions, with the edge condition, and s ubdomain basis functions. Placement of basis functions around the corn er cutout is discussed. Results are presented showing the coupling bet ween modes on a single patch, coupling between the modes on adjacent p atches, and the effects of gap coupling the patch to a 50 ohm feedline .