Frequency-Selective Absorbers With High Design Flexibility of Reflective Band

Two frequency-selective absorbers (FSAs) with one and two reflective bands are proposed in this letter. The first FSA realizes a single reflective band, which can be altered in a very wide range between two absorptive bands. Simulation results show that the center frequency of the reflective band with high selectivity and good flatness is adjusted from 5.7 GHz to 9.5 GHz by changing the dimension of the structure. The second FSA achieved two reflective bands which can be independently or simultaneously adjusted in wide frequency. Simulation results exhibit that in the band of 2.99 GHz to 13.15 GHz, three absorptive bands and two reflection bands appear alternately, and the first and the second reflective bands can be structurally adjusted from 5.38 GHz to 7.08 GHz and from 9.05 GHz to 11.17 GHz, respectively. The good agreement between the measurement and the simulation results verifies the design.