Experimental study of the two-layer electromagnetically coupled rectangular patch antenna

Experimental results on the characteristics of two-layer electromagnetically coupled rectangular patch antennas are presented. In addition to the relatively large bandwidth region that occurs when the separation between the two layers is less than 0.15 wavelength, a high-gain region is found when the separation exceeds 0.3 wavelength. The relative sizes of the parasitic and fed patches are found to have significant effects on the resonant input resistance and bandwidth.