Characteristic modes analysis for patch antenna

This paper shows a characteristic modes analysis for patch antenna. Characteristic modes analysis (CMA) solves scattering and radiation problems of metals approximately by using eigenvalue equations. Characteristic modes have the useful property of being orthogonal on the metal surface. The total current distribution is calculated by summation of the weighted eigencurrents. Therefore, it is applicable for radiation and scattering problems, pattern synthesis and antenna shape synthesis. In this paper, we compare the electromagnetic field distribution by a rectangular patch antenna calculated from theory of characteristic modes (TCM) and the magnetic wall model. We show that the mode of the patch antenna calculated by TCM closely approximates the mode of the magnetic wall model.