Graphene based metamaterial lens for terahertz applications

This paper introduces a graphene metamaterial transmitarray designed for terahertz applications. The unit-cell element is a multilayered metamaterial structure of a graphene split ring resonator (SRR) with two variable gaps with tunable conductivity. The metamaterial properties of the unit-cell element are investigated from 0.74 THz to 0.94 THz for different conductivities of the graphene material. A parametric study of the transmission properties of the metamaterial unit-cell element is investigated. The radiation characteristics of 169 unit-cell elements of the three layers graphene metamaterial lenses are analyzed for different applied DC voltages. The gain and side-lobe level of the proposed lens are improved by using an averaging process on the transmission phase used for array construction. The lens introduces a high gain of about 18.5 dB at frequencies 0.83 THz, 0.85 THz, and 0.86 THz for chemical potentials = 0.4eV, 0.5 eV, and 0.8eV, respectively. A full wave simulation is used to design and analyze the radiation characteristics of the graphene based metamaterial lens.