Low-profile multi-polarization and pattern reconfigurable antenna based on metasurface

In this letter, a low-profile metasurface (MS) antenna with multi-polarization and pattern reconfigurability is presented. The antenna mainly consists of two parts, including a loop antenna fed by balun, and a MS antenna excited by the coupled aperture. When switching the PIN diode and rotating the MS, the multi-polarization and pattern reconfigurable ability of the antenna is obtained. While the loop antenna is excited, a horizontally linear polarized (HLP) wave and omnidirectional pattern are obtained. Besides, when the MS is operated, due to the differential phase between the orthogonal surface impedance components, the antenna can be switched between vertical linear polarization (VLP), left-hand circular polarization (LHCP), and right-hand circular polarization (RHCP). Furthermore, the antenna could achieve a directional pattern. As the simulated and measured results shown, the proposed antenna has an overlapped impedance bandwidth (IMBW) of 24.7% for all polarization modes and a 3-dB axial ratio (AR) bandwidth of 11.8% for L/RHCP modes. Moreover, the antenna owns a low profile of 0.06 lambda (under the operating centre frequency).