Gain Improvement of Wideband Patch Antenna at Millimeter-wave Band Using Novel Metamaterial Superstrate

A new design of a patch antenna with a broad bandwidth and high gain is demonstrated in this work. The 32 GHz wideband highly-directive patch antenna is covered with a novel single layer metamaterial-based superstrate to attain a significant gain improvement over a wide bandwidth. A new multi-resonant dual face unit cell with four asymmetrical patches and apertures is used as a building block of the superstrate. The superstate performing as a frequency selective surface (FSS) offers a partial reflection that is based on the positive phase gradient concept. The results show a 10.5 dB increase in the gain which is about 210% enhancement over the single antenna gain at 32 GHz. The proposed antenna attains a broad impedance bandwidth of 32-43.1 GHz (29.6%), and a 3-dB radiation bandwidth of 12.6%.