Frequency-Reconfigurable Slot Antenna Using Metasurface

In this paper a metasurface (MS) based wide-band frequency reconfigurable slot antenna is proposed and studied. The proposed antenna is composed of a circular slot antenna and a circular MS. The MS placed atop the slot antenna consists of circular unit cells with square hole (like ancient Chinese coins). The antenna is compact with a height of 1.5mm and a diameter of 50mm. The equivalent relative permittivity of the MS is changed when the polarization direction of incident wave changes due to the anisotropy of the MS. Therefore, the resonant frequency of the antenna can be tuned by rotating the MS around the center with respect to the slot antenna. The proposed antenna provides a wide frequency tuning range of 2.58-4.0 GHz (43.2%) and an operation band (S-11< -10dB) from 2.31 to 4.42 GHz (61%), thus it can be applied to multiple wireless communication applications such as WLAN (2.4-2.4835 GHz) and WiMax (3.3-3.8 GHz). The antenna is designed and optimized using computer simulation and the simulated performances are presented.