Directive wideband cavity antenna with single-layer meta-superstrate

A new wideband and enhanced gain Fabry-Pérot cavity antenna is presented in this letter. The Fabry-Pérot cavity is established between a single-layer metamaterial-based partially reflective surface (PRS) and a simple feeding slot antenna. The unit cell of the PRS consists of printed and etched square rings on both sides of the superstrate. A 6 × 6 array of the unit cells is optimized to produce a positive reflection phase gradient required for the gain enhancement. Simulated results of the designed Ku-band antenna demonstrate an impedance bandwidth of 13.1-15.3 GHz (15.5%) with a gain enhancement up to 8.2 dB (i.e., 150% gain increase above the feeding antenna) and a 3 dB radiation bandwidth of 18.7%. Experimentally observed reflection and radiation responses of the fabricated prototype validate the simulated results.