Ultrawideband metamaterial absorber for oblique incidence using characteristic mode analysis  

作　　者：KUN GAO XIANGYU CAO JUN GAO TONG LI HUANHUAN YANG SIJIA LI 

机构地区：[1]Shaanxi Key Laboratory of Artificially-Structured Functional Materials and Devices,Air Force Engineering University,Xi'an 710051,China

出　　处：《Photonics Research》2022年第12期2751-2759,共9页光子学研究（英文版）

基　　金：National Natural Science Foundation of China(62171460);Natural Science Basic Research Program of Shaanxi Province(2022JM-319,2022JQ-685,20210110,20200108,20220104,2020022)。

摘　　要：An ultrawideband,polarization-insensitive,metamaterial absorber for oblique angle of incidence is presented using characteristic mode analysis.The absorber consists of conductive meander square loops and symmetric bent metallic strips,which are embedded with lumped resistors.With the aid of modal currents and modal weighting coefficients,the positions of the lumped resistors are determined.After that,the equivalent circuit(EC)model and admittance formula are proposed and analyzed to further understand the working principle and ultrawide bandwidth.The proposed absorber measures an absorption bandwidth of 4.3–26.5 GHz(144.1%in fractional bandwidth)for 90%absorptivity under normal incidence.At the oblique angle of incidence of 45°,the bandwidth of 90%absorptivity is still 5.1–21.3 GHz(122.72%)for transverse electric(TE)polarization,and 6.8–29.5 GHz(125.07%)for transverse magnetic(TM)polarization.The good agreement among simulation,measurement,and EC calculation demonstrates the validity of the proposed method and indicates that the method can be applied to other microwave and optical frequency bands.The proposed metamaterial absorber can be widely applied in electromagnetic compatibility,electromagnetic interference,radar stealth,and biomedical detection.

关 键 词：POLARIZATION ABSORBER MODE 

分 类 号：O441.4[理学—电磁学] TB34[理学—物理]