Dual-band dual-polarization reconfigurable terahertz antenna enabled by graphene plasmonic high-impedance surface

A dual-band terahertz antenna with dynamically reconfigurable polarization states from linear to circular polarization through graphene-based active control is proposed. The design leverages a cross-polarization conversion mechanism in a graphene high-impedance surface supporting two orthogonal surface plasmon polariton (SPP) eigenmodes with distinct resonance frequencies. By strategically exploiting the phase difference among these orthogonal SPP modes under electrostatic gating control, we achieve continuous polarization transformation from linear polarization (LP) to circular polarization (CP) through Fermi energy modulation (0 to 1 eV). Remarkably, the antenna exhibits dual-band operation with independent polarization control: right-hand circular polarization at 0.71 THz and left-hand circular polarization at 1.03 THz when biased at 1 eV. Full-wave simulations demonstrate axial ratio tuning from >40 dB (pure LP) to <3 dB (high-purity CP) with 98.7% polarization conversion efficiency. This dual-band dual-polarization reconfigurability, coupled with 2.1-dBic gain variation across states, enables simultaneous transmit–receive functionality in multipath terahertz environments. The proposed architecture establishes a paradigm for active polarization control in terahertz systems.