Designing miniaturized metamaterial absorber with tunable multiband characteristics for THz applications

In this paper, a novel tunable metamaterial absorber having multiple bands is presented for solving sensing-related issues in THz applications. Initially, a zigzag shaped metamaterial absorber with multiband response is reported and then, a tunable absorber is proposed to cover a wide THz spectrum. The proposed tunable absorber has six ‘V’ shaped stubs with graphene at the edges to realize six absorption bands of 0.65, 1, 1.33, 1.45, 1.74 and 1.95 THz. The tuning of absorption bands is realized by varying the chemical potential of graphene by controlling the electrostatic gating and hence, provides tunable absorption characteristics in the optical regime. The absorber is designed with a polyimide substrate having a unit cell dimension of 0.14 × 0.14 λo, which is smaller when compared to similar literature. The simulation result shows a better absorption rate of > 90% over most of the operating bands. The influence of material on the absorption peak is analysed by using different types of conductors and dielectric materials.