Metasurface Designs for Wideband Circularly Polarized Patch Antennas: A Review and An Interpretative Study

A metasurface can enhance not only the impedance bandwidth of a circularly polarized patch antenna but widen the 3-dB axial ratio (AR) bandwidth in the boresight direction. This paper reviews design techniques using metasurfaces for wideband circularly polarized patch antennas. Furthermore, the authors summarized interpretative discussion to enhance the 3-dB axial ratio bandwidth using such techniques.