Gradient Distribution of Metasurface based Antenna Performance Enhancement

In this paper, low-profile, high gain and wideband antenna loaded with a single metasurface layer is proposed. The metasurface is composed of a single layer of periodic square patches placed on a dielectric layer, where the metallic layer consists of an array distribution of 5x5 square patches in a gradient form symmetrically located around the central column, and the proposed antenna is fed by the aperture coupling technique. This metasurface based antenna preserves a low profile of 0.137 lambda o at a frequency of 6.47GHz. Furthermore, wideband characteristics for both the gain and impedance bandwidth have been simultaneously obtained. The -10dB impedance bandwidth of the proposed antenna is about 32% (6.29-8.69 GHz) and gain of 9.75dBi. The simulation results show that the metasurface based antenna design highly improves the overall performance compared to the same antenna without a metasurface layer.