Design of Wideband Multibeam Multimode Vortex Antenna

This paper presents a wideband antenna for generating multibeam multimode vortex beams. The proposed mirrored M-shaped element can achieve 31.7% (27.49-37.84 GHz). A wideband circularly polarized horn loaded with a dovetail substrate is designed to achieve an axial ratio bandwidth of 53.6% (23.6-40.9 GHz). Based on the aperture superposition method, a reflectarray of
$20\times 20$
elements is designed to simultaneously generate four vortex beams radiating in different directions with
$\pm 1$
and
$\pm 2$
orbital angular momentum modes in the wide frequency range of 27–37 GHz, providing a potential solution for the mode multiplexing of vortex electromagnetic waves in future wireless communications.