Wideband Dual Circularly Polarized Open-Ended Waveguide Antenna

A wideband dual circularly polarized antenna element based on open-ended waveguides is proposed in this paper. It adopts a cross-shaped structure with two orthogonal staggered arms, and each arm corresponds to a rectangular open-ended waveguide. Feed waveguides are respectively arranged on the side of the wide walls of the two open-ended waveguide arms, and the left-handed circularly polarization (LHCP), as well as the right-handed circularly polarization (RHCP) are excited. This structure removes the high axial ratio from the working band, thus realizing a wider axial ratio bandwidth. It is shown from the simulated results that the proposed dual circularly polarization open-ended waveguide antenna has an LHCP axial ratio band-width of 27.3 % and an RHCP axial ratio bandwidth of 28.5 %. This design lays the foundation for the subsequent construction of large-size arrays.