Reconfigurable Broadband Transmissive-Type Polarization Converter Based on Liquid Crystal Metasurfaces

This letter presents a reconfigurable broadband transmissive-type linear cross-polarization converter (LCPC) based on liquid crystal (LC) metasurfaces. The proposed structure exhibits broadband linear cross-polarization conversion capabilities and asymmetric transmission (AT) effects, with the ability to tune the operational bandwidth by adjusting the applied bias voltage. Experimental results demonstrate that, without external biasing, the structure can achieve linear cross-polarization conversion functionality with polarization conversion ratio >0.97 over the frequency range of 107.8 GHz to 133.6 GHz. Additionally, the AT effect can be realized within the same frequency band. When a saturated bias voltage of 8 V is applied, the operational bandwidth shifts from 101.7 GHz to 129.3 GHz, resulting in a tuning rate of approximately 4.4%. Compared with traditional grating-based three-layer structures, the proposed design, features low cost, simple configuration, and tunable linear cross-polarization conversion and AT effects, providing new possibilities for practical applications that require flexible operation across varying frequency bands in fields such as wireless communication and imaging.