Tri-band terahertz polarization reconfigurable reflective metasurface based on liquid crystal

Terahertz technology is poised to revolutionize next-generation wireless communication systems, such as 5G-A and 6G, by addressing the growing need for efficient electromagnetic wave modulation in the terahertz frequency band. In this study, we present a reflective metasurface comprising dual metal layers and a tunable liquid crystal medium, designed to achieve dynamic linear-to-circular polarization conversion. Experimental results demonstrate polarization conversion across three frequency bands: 248–254, 265–278, and 287–292 GHz. Furthermore, left-hand circular polarization (LHCP)-to-right-hand circular polarization (RHCP) switching is achieved at 248–254 and 287–292 GHz, with a stable RHCP state observed at 265–278 GHz. These findings validate the device's ability to dynamically control polarization states through applied bias voltage. By enabling precise and flexible modulation, this metasurface provides a scalable and efficient solution for reconfigurable intelligent surfaces, paving the way for advanced terahertz communication systems in future wireless networks.