Quad-Band Terahertz Absorber Based on Dipolar Resonances of Metamaterial Resonator

A novel design of a quad-band metamaterial absorber, which consisted of only a metallic resonator on top of a dielectric spacing layer and a metallic board on the bottom, is presented in this paper. Four near-perfect resonance peaks are observed in this structure. The combination of four dipolar resonances in different sections of the resonator results in the quad-band absorption. The absorption performance, including the operating frequencies and number of the resonance peaks, of the metamaterial can be controlled by changing the parameters of the resonator. The quad-band absorption is very promising for highly integrated absorbing devices.