A Microstrip Antenna Achieves Dual Polarization Conversion by Rotating Metasurface

To expand the channel capacity of a traditional single-polarization reconfigurable antenna, a design method for a dual-polarization reconfigurable microstrip antenna loaded with a passive metasurface was proposed. By utilizing the equivalent circuit method and characteristic modeling analysis, this method can provide guidance for designing an integrated antenna with adjustable dual-polarization. An antenna with an operating frequency of 3.5 GHz is designed, which is composed of four layers, from top to bottom: metasurface layer, radiation patch layer, feed layer, and reflector layer. By rotating the metasurface layer to adjust its relative position with other fixed layers, the designed antenna can achieve a mutual transformation between orthogonal dual-linear polarization (Horizontal polarization/Vertical polarization) and orthogonal dual-circular polarization (Left-handed circular polarization/Right-handed circular polarization), while ensuring antenna performance. The simulation and measurement results of the designed antenna demonstrate that it possesses competitive gain and polarization isolation performance, with a 3 dB axial ratio bandwidth reaching 17.4% in the dual-circular polarization state.