Broadband Circularly Polarized Antenna Based on Integrated Substrate Gap Waveguide

This paper proposes a new broadband circularly polarized (CP) antenna for 5G millimeter waves based on the integrated substrate gap waveguide (ISGW). The broadband circularly polarized antenna etches a rectangular slot on the PEC on the upper surface of the ISGW, and then adds two rectangular perturbation patches of different shapes on the rectangular slot, thereby realizing circularly polarized wave radiation. To expand the 10dB return loss bandwidth and axial ratio bandwidth of the slot circular polarization antenna based on the substrate integrated gap waveguide, a new dielectric plate is added above the ISGW, and a cross-shaped patch is added above the dielectric plate. This cross-shaped patch not only functions as a parasitic patch but also circularly polarized radiation, thereby achieving the purpose of expanding the 10dB return loss bandwidth and axial ratio bandwidth of the circularly polarized antenna.