Broadband microwave absorption properties of polyurethane foam absorber optimized by sandwiched cross-shaped metamaterial**Project supported by the National Key Research and Development Program of China (Grant No. 2017YFA0204600), the National Natural Science Foundation of China (Grant No. 51802352), and the Fundamental Research Funds for the Central Universities of Central South University, China (Grant No. 2018zzts355).

Abstract

The effect of a sandwiched cross-shaped metamaterial absorber (CMMA) on microwave absorption properties of the double-layered polyurethane foam absorber (PUFA) is investigated. Combining with the sandwiched CMMA, the bandwidth of −10-dB reflection loss for PUFA is broadened from 7.4 GHz to 9.1 GHz, which is attributed to the overlap of two absorption peaks originating from CMMA and PUFA, respectively. The values of the two absorption peaks located at 10.15 GHz and 14.7 GHz are −38.44 dB and −40.91 dB, respectively. Additionally, distribution of surface current, electromagnetic field and power loss density are introduced to investigate the absorption mechanism of the CMMA. The electromagnetic field distribution of the double-layered PUFA and the three-layered hybrid absorber are comparatively analyzed to ascertain the influence of CMMA. The results show that the proposed hybrid absorber can be applied to the anti-electromagnetic interference and stealth technology.