Design Low Profile and Wideband Antenna Based on Metasurface

Abstract

In this article, high gain, low-profile and wide bandwidth antenna, loaded with a single metasurface (MS) layer is proposed. The metasurface layer is composed of two sizes of periodic patches distributed along two dimensions. The size of large unit is divided to small four parts, establishing an approach wo operate with a wide range of frequencies. Therefore, the variations in the unit cell size assist to widen the proposed antenna bandwidth and matching enhancement as well. This metasurface layer is added above the slot antenna, separated by a distance (hair). The parameter hair plays a vital role in determining the overall performance. Although the whole antenna consists of two layers, it still has low profile of 0.115 λo, where λo is the wavelength at centre frequency of 6.2 GHz. The most important achievement in our proposed antenna that it has wideband characteristics for both gain and impedance bandwidth simultaneously. The impedance bandwidth value is 5.8% ranged from 6.15GHz to 6.52GHz for the slot antenna alone, while the slot antenna loaded with the metasurface layer has the value of 40% impedance bandwidth from 5.62GHz to 8.43GHz. The peak gain attained in this research is 5.6dB, while it becomes 8.78 when adding the metasurface layer to the slot antenna. The gain enhancement is more than 3dB, considered as a good starting point to build antennas having high gains with no need to use antenna arrays which require special attention in their designs. Simulation results are as expected and provide a good comparison for the slot antenna before and after adding the metasurface to demonstrate the performance enhancement. The software used in all simulations is computer simulation technology CST.