The design of a triple-band wide-angle metamaterial absorber based on regular pentagon close-ring

We present three implementation methods and structures using regular pentagon close-ring (PCR) to obtain the characters of triple-band wide-angle metamaterial (MTM) absorber. The proposed metamaterial absorbers are composed of a periodic array with single layer or multi-layer ultrathin dielectric substrates, PCRs, and metal ground. By parametric simulation and optimization, the metamaterial absorbers have significant achievements that perform three distinct absorption peaks for different resonant frequencies. All the absorption rates of emerging peaks with normal incidence are greater than 99% as well as absorptivity for wide incident angles are excellent in both simulated and experimental data. The method utilizing PCRs puts forward a flexible way to design and fabricate multi-band, wide-angle, and ultrathin metamaterial absorbers.