Miniaturized meandered ring graphene-metal metasurface with wide angle control on the transmitted wave

In this paper, a miniaturized transmissive metasurface using graphene-metal in the 3.5 THz frequency range is proposed and designed to control the wavefront of the transmitted wave. The designed unit cell has four identical ultra-thin layers. Each layer contains a meandered ring-shaped slot carved in a metal sheet, which is partially filled with four graphene patches in symmetrical places. By employing the meandered shape slots, the lateral dimensions of the unit cells are reduced to 0.19 of the free space wavelength, which, to the best of our knowledge, is the most miniaturized designed structure among the existing transmissive metasurfaces in the literature. Full wave simulations confirmed that without any physical changes and by just altering the spatial distribution of the chemical potential of the graphene patches, wave-front control is achieved. The achievements include beam steering and beam splitting with numerous discrete angles up to 63° and beam focusing with optional focal lengths. It is envisaged that besides 6G wireless telecommunications, this structure could also be beneficial for THz imaging, nano-photonic and opto-electronic devices.