Polarized reconfigurable terahertz OAM antenna array based on 2D electromagnetic functional materials

A polarized reconfigurable vortex wave antenna array operating in the terahertz band is proposed. Based on three two-dimensional (2D) materials, namely, graphene, vanadium dioxide (VO₂), and perovskite, an antenna element with switching polarization modes was designed. By adjusting the electromagnetic parameters of different 2D materials, the antenna element can be reconstructed between wideband circular polarization and ultra-wideband non-circular polarization. Furthermore, a uniform circular array (UCA) was constructed using eight independent elements. In the wideband circular polarization mode, the impedance bandwidth (IBW) of the UCA is 5.28-9.06 THz (relative bandwidth was 52.7%), and the axial ratio bandwidth is 5.77-6.76 THz. In the ultra-wideband non-circular polarization mode, the IBW is 2.37-15.31 THz (relative bandwidth 146.4%). By specifying the azimuth angles of antenna elements at different positions to meet the feeding conditions of equal amplitude and equal phase difference of adjacent antenna elements, vortex beams with the mode number l=0, ±1, ±2, and ±3 can finally be generated. The proposed UCA has excellent application prospects in 6G communication.