Optimization of Patch Antennas Feeding Point for Circular Polarization Applying the Theory of Characteristic Modes

The circular polarization of patch antennas or square patches can be achieved with a single feeding point, which, according to the state of the art, is located on the diagonal of the patch, without indicating more precision in its location. An analysis by means of the Theory of Characteristic Modes allows to corroborate this hypothesis, but at the same time, by testing several feeding points on the diagonal, it is possible to easily optimize its location achieving an appropriate circular polarization. Simulations are performed with the FEKO program.