A Broadband Circularly Polarized Antenna Using Transmissive Polarization Conversion Metasurface

ABSTRACT With the rapid development of modern wireless communication technology, antennas, as a core component of the wireless communication system, have become a research focus. The axial ratio (AR) of an antenna is particularly critical to its overall performance. Increasing AR bandwidth can ensure circular polarization performance, enhance system compatibility, and improve anti‐interference capabilities. This paper presents a design of a circularly polarized patch antenna based on metasurface technology. By incorporating a transmission‐type polarization conversion metasurface, copper plates embedded vertically in the ground plane, and n‐shaped parasitic patches, significant improvements in antenna performance are achieved. The tests show that the antenna achieves a 43.4% S 11 bandwidth within the frequency range of 4.94–7.68 GHz, and a 31.4% 3 dB AR bandwidth within the range of 4.83–6.43 GHz, demonstrating excellent performance. This study provides new technical support and design ideas for the field of wireless communication.