A Sequentially Rotated Array of Polarization-Conversion Patch Antenna Using Metasurface

In this paper, metasurface-based patch antennas are arrayed in a sequentially-rotated layout for a high gain and broadband circularly polarized (CP) radiation. The single element is a rectangular patch, which is incorporated with a metasurface composed of 4×4 rectangular loops with diagonal strip in order to convert linearly-polarized wave from the patch into a CP wave. The array is fed by a sequential phase network based on series-parallel strips. The ANSYS Electronic Desktop is used for the simulations through this work. The final design has been realized and tested. The prototype yields a measured |S11| < −10 dB at 8.6 – 10.5 GHz, which agreed rather closely with the simulated value of 8.45 – 10.5 GHz. Moreover, the antenna achieves a broadband right-hand CP radiation; i.e., it yields a 3-dB axial ratio bandwidth of 15.38% (8.88 – 10.36 GHz), the peak broadside gain of 11.8 dBic, and a radiation efficiency of > 80%.