Wideband Circularly Polarized Antenna Based on a Non-Uniform Metasurface

This paper presents a non-uniform metasurface (MS)-based circularly polarized (CP) antenna that is able to perform with a wideband operation characteristic. A squared patch with truncated corners was chosen as a radiating CP source. Then, unlike the conventional CP MS antennas with a uniform MS, the proposed design employed a non-uniform MS placed above the driven patch. Apart from increasing the impedance bandwidth, the non-uniform MS was also capable of generating two additional CP bands in the high-frequency region, which contributed to significantly increasing the antenna's overall performance. For demonstration, an antenna prototype was fabricated and experimentally tested. The measured operating bandwidth of the fabricated antenna was about 30% and the broadside gain within this band was around 6.6 dBic. Compared to the other reported CP MS antennas in the open literature, the proposed design has the advantages of very wideband operation with a comparable size and gain.