Manipulation of sub-terahertz waves using digital coding metasurfaces based on liquid crystals

This paper presents a novel sub-terahertz liquid crystal (LC) phase shifter based on digital coding metasurfaces. The proposed structure consists of metal gratings and resonant structures. They are both immersed in LC. The metal gratings function as reflective surfaces for electromagnetic waves and electrodes for controlling the LC layer. The proposed structure changes the state of the phase shifter by switching the voltage on every grating. It allows the deflection of LC molecules within a subregion of the metasurface structure. Four switchable coding states of the phase shifter are obtained experimentally. The phase of the reflected wave varies by 0 degrees, 102 degrees, 166 degrees, and 233 degrees at 120 GHz. Due to the presence of the transverse control electric field, modulation speed is approximately doubled compared to the free relaxation state. This work provides a novel idea for wavefront modulation of phase.

Automated summary

This paper presents a novel sub-terahertz liquid crystal (LC) phase shifter based on digital coding metasurfaces. The proposed structure changes the state of the phase shifter by switching the voltage on every grating, allowing the deflection of LC molecules within a subregion. Four switchable coding states of the phase shifter are obtained experimentally. This work provides a novel idea for wavefront modulation of phase.