Gain enhancement for planar Quasi-Yagi antenna with zero-index metamaterial

Abstract

A zero-index metamaterial (ZIM) structure is proposed for the gain enhancement of a planar Quasi-Yagi antenna on X-band. The zero permittivity point of the proposed ZIM structure is obtained at the frequency around 8.5 GHz. The ZIM unit cells are layout into the aperture of a planar Quasi-Yagi antenna to improve the gain performance. Two antennas are simulated and fabricated for a comparison, the planar Quasi-Yagi antenna loaded with the proposed ZIM cells and the conventional one. And the measurement results exhibit a gain enhancement of 0.5-2.14 dB in the frequency band of 8.7-11.5 GHz and the gain enhancement of the ZIM cells is confirmed.