High-directivity antenna using reconfigurable near-zero index metamaterial superstrates

Abstract

The near-zero refractive index metamaterials (ZIM) have attracted more and more attentions because of their novel properties. In this paper, a theoretical analysis of a patch antenna with different ZIM superstrates has been given, which gives an insight into the mechanism of directivity enhancement using three different ZIM metamaterials as the antenna's superstrates. It shows that double near-zero (permittivity and permeability are near zero, DNZ) metamaterial superstrate can converge the aperture E-field and H-field of the antenna simultaneously. The increase of 9.2dB of radiation directivity can be obtained.