Broadband microwave absorption properties of polyurethane foam absorber optimized by sandwiched cross-shaped metamaterial<xref rid="cpb_27_12_127801fn1" ref-type="fn">*</xref><fn id="cpb_27_12_127801fn1"><label>*</label><p>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).</p></fn>

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).

He Long-Hui, Deng Lian-Wen^†, Luo Heng, He Jun, Li Yu-Han, Xu Yun-Chao, Huang Sheng-Xiang

(color online) (a) Real (ε′) and (b) imaginary (ε″) parts of complex permittivity of PUFA₂ filled with different mass fractions of short carbon fiber.