A high-gain lens antenna based on Gradient-Index metamaterial

A high-gain lens antenna using Gradient-Index metamaterial unit cell is designed and demonstrated for 10 GHz-operating frequency. This lens consists of a cavity patch antenna and 8 layers of non-resonant metamaterial array elements separated with air gaps. The effective parameters of this unit cell are extracted, then its gradient refractive index is achieved through changing the size of unit cell. The obtained simulation results demonstrate that when the proposed GRIN lens is placed in the front of the feed aperture (F/D=0.4), a collimated beam is achieved. The maximum realized gain of this lens is 15.3 dBi and its 1 dB gain bandwidth is 1 GHz. In addition, it provides low side lobe levels in both planes in the obtained bandwidth.