High-Q Dual-Band Graphene Absorbers by Selective Excitation of Graphene Plasmon Polaritons: Circuit Model Analysis

TL;DR

This paper introduces a circuit model-based design for dual-band terahertz graphene absorbers that selectively excite specific plasmon polaritons, validated by simulations showing accurate resonance predictions.

Contribution

It presents a novel analytical circuit model approach for designing dual-band graphene absorbers by selectively exciting specific plasmon polaritons, validated through full-wave simulations.

Findings

Analytical circuit model accurately predicts resonance frequencies.

Design method enables selective excitation of GPPs for dual-band absorption.

Simulation results confirm the validity of the analytical approach.

Abstract

This article presents the design of two dual-band graphene-based absorbers for terahertz frequencies. The absorbers are composed of two-dimensional (2D)arrays of ribbons and disks printed on a ground plane backed dielectric spacer. The design is based on the excitation of a specific plasmon polariton of the graphene patterned array at each resonance band. An analytical circuit model is used to derive closed-form relations for the geometrical parameters of the absorber and graphene parameters. The graphene patterned array appears as a surface admittance made of an infinite parallel array of series RLC branches. Each branch is equivalent to a graphene plasmon polariton (GPP) providing a distinct resonance mode. The design procedure is based on selectively exciting the first two GPPs. This means that two of the parallel RLC branches are selectively used in the circuit model analysis. The results obtained using the analytical solution are compared with the full-wave simulations in HFSS. The agreement between the results validates the developed design method.