可共形透明宽带超材料吸波体设计与分析

Design and analysis of conformable transparent broadband metamaterial absorber

为解决传统吸波体吸收带宽窄和不可弯曲共形等问题,设计了一款柔性宽带超材料吸波体。该超材料由氧化铟锡(Indium tin oxide,ITO)电阻膜和聚对苯二甲酸乙二醇酯(Polyethylene Terephthalate,PET)组成,周期单元为ITO-PET-ITO三明治结构,通过表面电流和等效电路模型分析了结构单元的吸波机理。仿真结果表明,电磁波正入射时超材料在10~21.7 GHz频率范围内吸收率均高于90%,厚度仅为0.066λ_(0)(λ_(0)为最低截止频率对应的波长),结构单元的对称设计使其具有极化不敏感和较好的角度稳定性。将所提出的超材料进行实物加工和测量,实测结果与仿真结果基本吻合。该超材料具有柔性、透明、宽带、极化不敏感等特点,在电磁隐身和雷达吸波等领域具有潜在的应用价值。

A flexible broadband metamaterial absorber was designed to solve the problems of narrow absorption bandwidth and inflexibility of traditional absorber.This metamaterial is composed of indium tin oxide(ITO)resistance film and polyethylene terephthalate(PET)in periodic sandwich structure.The absorbing mechanism of structural unit was analyzed by the surface current and equivalent circuit model.The simulation results show that the absorptivity of the metamaterial is higher than 90%from 10 GHz to 21.7 GHz at positive incidence of electromagnetic waves,and the thickness is only 0.066λ_(0)(λ_(0) is the wavelength corresponding to the lowest cut-off frequency).Offered the polarization insensitivity and excellent angle stability of the metamaterial was enabled with the symmetrical design of structural unit.The proposed metamaterial was processed and measured,and the measured results were consistent with the simulation results.The metamaterial has the characteristics of flexibility,transparency,broadband and polarization insensitivity,and it has potential application value in the fields of electromagnetic stealth and radar absorption.