Broadband Terahertz Beam-Steering Metasurfaces with Graphene-Controlled EIR Structures

Abstract

We investigate a terahertz metasurface that uses graphene as an active element and exploits its properties to achieve beam control and broadband phase modulation by varying the voltage to control the Fermi energy level of graphene. The array uses an EIR (electromagnetically induced reflectivity) structure, which has two adjacent resonant frequencies making it easier to achieve a 180° phase shift in both states of graphene, which in turn is used as 1-bit encoding. The array ideally achieves a beam deflection of roughly 30° and an operating bandwidth of about 35 GHz.