Wide-Angle Reflective Terahertz Beam Steering Metasurface Based on Cross-Polarization Conversion
Résumé
The terahertz (THz) frequency range is considered an important spectrum for future six-generation communication. However, the high propagation losses and poor penetration inherent to THz waves restricted its development. Wavefront manipulation techniques for beam steering to redirect the propagation directions are essential for mitigating these limitations. In this article, cross-polarization conversion-based phase engineering for THz reflective beam steering is presented. This approach has the advantages of enabling quasi-linear phase response with sufficient phase-shifting range and maintaining high reflection magnitudes over a wide frequency band. Furthermore, a four-port equivalent circuit is developed to explain the design principle and verify the effectiveness of the polarizers. As a result, the metasurfaces composed of the proposed unit cells achieve stable wide-angle beam steering with high reflection intensity and have continuous frequency-scanning capability. In addition, the metasurfaces are verified to support the high-quality quadrature amplitude modulation with 16 states with an acceptable power penalty in a non-line-of-sight THz link.