Enhanced transmission through a sub-wavelength aperture in a metal foil by using a complementary patch: Microwave optics analog

Experimental results show that a complementary metal patch located in front of a sub-wavelength aperture in a metal foil remarkably enhanced the microwave transmission. Without periodic pattern grooved over the sample, the transmission enhancement is not due to the conventional grating coupling of surface plasmons, but to peculiar resonating between the complementary patch and the aperture-excavated metal foil.