Wideband Terahertz Metasurfaces with Beam Manipulations

A wideband terahertz (THz) reflective metasurface with reconfigurable beam manipulation operating at 0.1THz is proposed in this paper. A novel 1-bit reconfigurable unit cell is designed and analyzed. Owning to the characteristics of phase change material (PCM), GeTe, the electrical property of the unit cell can be changed to provide 0- and 180-degree phase tuning. To validate the performance of the proposed active element, a coded reflective metasurface is demonstrated by utilizing the geometric phase compensation technique. The proposed metasurface achieves switchable directional beams at 0 and 30 degrees through distinct coded patterns, while maintaining the wide operating bandwidth ranging from 100GHz to 120 GHz with the stable realized gains of 22 dBi. The obtained results indicated the effectiveness of controlling beam angle and directivity and the feasibility of integrating PCM into THz devices. Hence, the proposed THz reflective metasurface shows its potential for future implementation in 6G applications.