Adjustable THz absorber exploiting nested graphene disk-ring

This work introduces a THz dual-band absorber with the capability of being tuned via external stimulation. A nested disk-ring graphene pattern is proposed on top of the lossless substrate while the other side of the substrate is coated by a thick layer of gold. The proposed absorber is modeled using an equivalent circuit model (ECM) and also simulated by the full wave method. A perfect match between the circuit model and numerical full wave simulation highlights the developed circuit modeling. Since the circuit modeling can reduce CPU time and need memory considerably. The impedance-matching concept interpretations are discussed in detail. Ample simulation results show the dual-band operation of the proposed absorber at 2 THz and 10 THz, while an interesting tuning capability is provided by changing chemical potentials. Such a simple and adjustable wave absorber is in demand for numerous applications ranging from medical imaging to indoor communication.