Broadband terahertz reconfigurable metasurface based on 1-bit asymmetric coding metamaterial

Terahertz metasurface has always aroused extensive attention for many years. However, terahertz reconfigurable metasurface is still a significant challenge. The broadband terahertz reconfigurable metasurface based on 1-bit asymmetric coding metamaterial is presented in this paper. The asymmetric metamaterial breaks the charge balance and provides multiple resonances, which is conducive to expanding the operating bandwidth. Conventional coding metamaterials change phase by varying the shape or size of the patch. The proposed metamaterial only disconnects or connects the metal lines in the metamaterial to obtain 1-bit phase information, which is beneficial for designing reconfigurable coding metasurface. Both simulated and experimental results show that the asymmetric metamaterial efficiently reflects the normal incident waves at 0.34-0.49 THz with a relative bandwidth of 36%, and the reflection coefficients are measured to exceeds 80%. Furthermore, the simulation and experimental results of the metasurface show that the normal incident wave is reflected as a double beam of the expected angle by configuring metamaterials with different coding sequences. This work provides important potential applications for the development of valuable dynamic terahertz beam scanning devices.