Studies on input impedance and coupling of a dual polarized two port microstrip antenna

Multiport analysis with a cavity model is used to investigate the dual-port, dual-polarized microstrip patch. Using the equations derived, the normalized driving point impedance and the coupling are determined for a square patch with a feed port located at the center of one side. From the results presented it is clear that for dual polarization the coupling port should be located exactly in the middle of the orthogonal side of the square. This gives the minimum coupling for the other port location. The results obtained using the analysis are compared with the experimental results available in the literature and are found to be in good agreement with theory.<>