High-Gain and High-Aperture-Efficiency Cavity Resonator Antenna Using Metamaterial Superstrate

In this letter, a high-gain, aperture-efficient cavity resonator antenna using metamaterial superstrate is reported. Highly reflective compact metamaterial surface resonating at 10.15 GHz with measured 3-dB bandwidth stopband characteristic of 4.10 GHz from 8.1 to 12.2 GHz is proposed. Material property of the metasurface is studied by using the free-space technique. Next, the metasurface is used as a superstrate to a patch antenna operating at 10.09 GHz, forming Fabry–Perot cavity. Gain enhancement of 11.85 dB in H-plane and 12.5 dB in E-plane with improved cross-polarization level and front-to-back ratio is observed. The prototype cavity antenna shows calculated gain of 16.35 dB achieving 92.42% of maximum gain due to effective aperture area in H-plane.