Dual-Frequency Polarized Reconfigurable Terahertz Antenna Based on Graphene Metasurface and TOPAS

A hybrid dual-frequency polarized reconfigurable terahertz antenna is designed and studied. Graphene and TOPAS are employed as the polarization conversion metasurface and dielectric substrate, respectively, enabling tunable polarization conversion and circular polarization. TOPAS is a good substrate material for broadband THz components due to its low absorption. By adjusting the chemical potential of graphene between 0 eV and 0.5 eV, the polarization state in the band of 1 THz (0.76–1.02 THz) and 2.5 THz (2.43–2.6 THz) can be reconstructed. Thanks to the multilayer graphene structure and low absorption TOPAS, the graphene metasurface exhibits a broad bandwidth of 0.26 and 0.17 THz, respectively, in the band of 1 THz and 2.5 THz. The working state of the circularly polarized antenna and linearly polarized antenna can be switched in the bands around 1 THz (0.7–0.75 THz, 0.96–1.04 THz) and 2.5 THz (2.42–2.52 THz), respectively, without changing the physical geometry. Moreover, the graphene antenna, metasurface, and hybrid structure are tested, respectively, to verify that the components do not interfere with each other in performance. The hybrid antenna shows great potential in tunable terahertz devices and related applications.