Metamaterial modeling in circuit level for THz wave manipulation

Leveraging both method and concept a two-layer THz absorber based on periodic arrays of graphene rings is proposed. The design methodology based on the equivalent circuit model is developed for the proposed absorber. The device is described as an impedance and also simulated by the FEM full-wave method to verify the circuit model accuracy. According to the simulation results, the proposed THz absorber can show perfect absorption from 0.5 THz to 3.5 THz while adjustability capability is obtained for different chemical potentials. Additionally, the sensitivity against geometrical parameters and different incident angels is investigated. Based on the provided results and the simplicity of the structure, the proposed absorber is an ideal candidate for several applications ranging from security to medical imaging.