Wideband and Low-Profile Multi-Polarization Reconfigurable Filtering Antenna Based on Nonuniform Metasurface

In this article, a wideband and low-profile multi-polarization reconfigurable filtering antenna based on metasurface (MS) is investigated. The proposed antenna consists of two layers, which are the feeding layer and the MS layer. The filtering function is achieved by utilizing a nonuniform MS and inserting a short via between the feedline and ground plane. Besides, by rotating the MS to change its surface current distribution, the antenna can switch among linear polarization (LP), left-hand circular polarization (LHCP), and right-hand circular polarization (RHCP). To demonstrate the simulated design, the proposed antenna is manufactured and measured. As the measured results show, when the antenna works in LP modes, it obtains an -10-dB overlapped impedance bandwidth of 22.4% and an in-band peak gain of 8.8 dBi. Furthermore, the antenna achieves 14 and 19-dB out-of-band radiation suppression levels for LP1 and LP2 modes, respectively. Whereas it operates in CP modes, the measured -10-dB overlapped impedance bandwidth and 3-dB axial ratio (AR) bandwidth of the antenna reach 26.5% and 22%, respectively. Meanwhile, its out-of-band radiation suppression level is more than 17.5 dB, with an in-band peak gain of 7.3 dBic. Hence, there illustrates a pretty good agreement between the simulated and measured results.