Low-Profile Wideband Dual-Circularly Polarized Metasurface Antenna Array With Large Beamwidth

One low-profile wideband dual-circularly polarized metasurface antenna (MSA) with large beamwidths is proposed. The proposed MSA is constructed by an array of corner-truncated polarization-rotation metasurface (PRMS) cells, and excited by a novel dual-feeding structure through a cross-like slot, which are specifically designed to simultaneously realize wideband impedance matching for the right- and left-handed circular polarization (RHCP, LHCP). Furthermore, benefiting from wideband and widebeam PR property and good polarization independence of the PRMS cells, the proposed MSA exhibits good RHCP and LHCP performances in a low profile of 0.069 λ0, including large axial-ratio bandwidths ARBWs of over 12.4%, large AR beamwidths over 80°, and a high polarization isolation of over 15 dB. In addition, combined with a sequential phase network, the proposed MSA is extended to construct a 2 × 2 dual-circularly polarized antenna array with large ARBWs of over 22.4% and high gains of over 11 dBi.