High-Gain and High-Efficiency GRIN Metamaterial Lens Antenna With Uniform Amplitude and Phase Distributions on Aperture

A gradient index (GRIN) metamaterial lens antenna with extremely high gain and high aperture efficiency is presented. The proposed antenna is much more advantageous in terms of gain and aperture efficiency without compromising in simplicity and stability. The gain and aperture efficiency are improved by using a new method to design the GRIN lens for a hybrid mode, which possesses both uniform amplitude and phase distributions on the aperture. At the center of frequency band (14.25 GHz), the proposed antenna achieves a gain of 26.6 dBi, which corresponds to aperture efficiency greater than 90%.