A Circularly Polarized Reconfigurable Antenna Based on Compact Metasurface

A reconfigurable antenna with dual circularly polarized (CP) radiation and compact size is shown in this paper. The antenna consists of 4 square-ring unit cells as the primary radiator, a Y-shaped patch acting as the CP source, and a reconfigurable feeding network. Two PIN diodes are utilized and positioned at the feeding network to provide polarization switching operation. Here, dual CP, left-hand CP (LHCP) and right-hand CP (RHCP) can be realized by turning ON/OFF two pin diodes. It is worth noting that using a reconfigurable feeding network can avoid unwanted effects of the biasing circuit and the diodes on the antenna performance. This approach is different from the conventional approach of using reconfigurable radiating elements. The simulated results demonstrate that the proposed CP reconfigurable antenna exhibits good performance for both LHCP and RHCP modes with the broadside gain of 4.9 dBi.