Five-Band Terahertz Metamaterial Absorber Based on a Four-Gap Comb Resonator

A novel and simple design of five-band terahertz absorber is investigated. This absorber consists of a four-gap comb resonator and a dielectric slab on top of a metallic board. The simulation results show that the structure has five distinct absorption peaks, each with the absorption of over 98%. Multiband absorption property can be explained by the overlapping of the LC resonances, dipolar response, and high-order resonance of the structure. Moreover, the design gives considerable freedom to shift or change the frequencies of the absorber by varying the arm lengths of the comb. The proposed absorber has potential applications in detection, imaging, and sensing.