An Ultrawideband Frequency Selective Surface Absorber With High Polarization-Independent Angular Stability

An ultrawideband frequency selective surface (FSS) absorber with high angular stability and polarization independency applied in a microwave band is proposed. The absorber is composed of three identical Teflon layers and dual FSS layers with distinct patterns. The miniaturized FSSs with unique patterns demonstrate advantages of facile manipulation of the impedance and multiple resonances in an ultrawide frequency range. The use of identical dielectric substrate greatly reduces the complexity in the absorber design, compared with the conventional way that requires variable dielectric constants for a multilayer structure. Experimental results reveal that more than 90% absorption rate in the frequency range of 2.79–20.62 GHz for normal incidence is achieved. The absorption rate can still retain more than 80% in the range of 4.41–20.93 GHz for both TE and TM polarizations with an incidence of 60°.