抗方阻波动的超宽带轻薄频率选择表面吸波体  

Ultra-wideband thin frequency-selective surface absorber against sheet resistance fluctuation

作　　者：王东俊 孙子涵 张袁 唐莉[2] 闫丽萍 Wang Dong-Jun;Sun Zi-Han;Zhang Yuan;Tang Li;Yan Li-Ping(Chengdu Aircraft Industrial(Group)Co.LTD.,Chengdu 610073,China;College of Electronics and Information Engineering,Sichuan University,Chengdu 610065,China;School of Electronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu 611731,China)

机构地区：[1]成都飞机工业(集团)有限责任公司,成都610073 [2]四川大学电子信息学院,成都610065 [3]电子科技大学电子科学与工程学院,成都611731

出　　处：《物理学报》2024年第2期145-155,共11页Acta Physica Sinica

基　　金：国家自然科学基金区域创新发展联合基金(批准号:U22A2015)资助的课题。

摘　　要：满足宽带、极化和入射角度稳定、轻薄和强吸收等高性能要求的电阻膜频率选择表面(FSS)吸波体设计难度大,且易因加工中方阻波动导致吸波性能变化.为此,本文首先分析了方阻波动影响电阻膜FSS吸波体性能的机理,提出抗方阻波动的FSS吸波体设计方法.在此基础上,提出利用不同层FSS阻抗随频率变化互补的扩展带宽方法,结合弯折小型化设计,获得了超宽带、极化和角度稳定的轻薄型抗方阻波动FSS吸波体.该FSS吸波体在TE和TM极化下,90%吸波带宽为1.50—20.50 GHz(相对带宽173%),厚度仅为0.093λ_(L).TE极化波80%吸波的角度稳定性可达45°,而TM极化波90%吸波的角度稳定性可达70°.当每层FSS方阻在12—30Ω/sq范围内波动时,吸波体的90%吸波带宽仍保持在167.0%.实验测试结果与仿真结果基本吻合,证明了所提方法的有效性.The design of thin frequency selective surface(FSS)absorber based on resistive film that meets the requirements of broadband,polarization independence,incident angle stability,and strong absorption is a challenging task.Fabrication tolerance of resistive film can result in fluctuations in sheet resistance,which negatively affects the absorber performance.To tackle these problems,this work firstly investigates how sheet resistance fluctuations affect the absorbing performance of resistive film FSS absorber.The analysis of simulated surface current density distribution and impedance reveals that the diversity of current paths provides an effective way to mitigate the influence of sheet resistance fluctuation.This is achieved by enabling flexible variation of surface current in response to sheet resistance fluctuations.Consequently,the variation of input impedance of the FSS absorber due to the fluctuation of sheet resistance is suppressed within a small range.Then,a method of extending bandwidth is proposed by employing the complementary variation of FSS impedance with frequency at different layers.By combining this approach with a miniaturization design,a thin and light FSS absorber is developed that exhibits ultra-wide bandwidth,polarization independence and angle stability while mitigating the effects of sheet resistance perturbation.The proposed FSS absorber achieves a 90%absorption bandwidth from 1.50 GHz to 20.50 GHz,covering Ku,X,C,S bands and part of the L and K bands,with a relative bandwidth reaching 173%.The absorber has a thickness of 0.093λ_(L) for both transverse electric(TE)polarization and transverse magnetic(TM)polarization,yielding a figure of merit(FoM,the ratio of the theoretical minimum thickness to the actual thickness)of 0.95,indicating that the thickness is close to the theoretical limit.The absorber maintains over 90%absorption rate for TM polarization at an incidence angle of up to 70°,and 80%absorption for TE polarization at 45°.Furthermore,the 90%absorbance bandwidth of the absorber r

关 键 词：频率选择表面 吸波体 薄型 超宽带 方阻波动 

分 类 号：O441[理学—电磁学] TB34[理学—物理]