基于迭代反演的非磁性材料复介电常数测量及初值选取方法  

A method of measuring complex ermittivity of nonmagnetic materials and selecting its initial value based on iterative inversion

作　　者：覃维 安书悦 陈帅 龚荣洲[2] 王鲜[2] Qin Wei;An Shu-Yue;Chen Shuai;Gong Rong-Zhou;Wang Xian(No.710 R&D Institude,CSSC,Yichang 443003,China;School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]中国船舶重工集团有限公司第七一〇研究所,宜昌443003 [2]华中科技大学光学与电子信息学院,武汉430074

出　　处：《物理学报》2023年第7期34-40,共7页Acta Physica Sinica

摘　　要：复介电常数是反映材料宏观电磁性质的重要参数,电磁领域相关材料和器件的选取、设计及应用都必须基于材料在工作频段的电磁参数.数值迭代法是反演计算材料复介电常数的重要方法,但一直存在难以准确给出迭代初始值的问题.本文基于吸波材料介电常数与反射率的关系,提出了一种迭代法反演吸波材料介电常数的初值选取方法,以此为基础构建了一种利用反射参数反演计算单层吸波材料、多层材料中唯一未知层材料复介电常数的方法,并通过实例测试验证了方法的有效性.Complex permittivity is an important parameter to reflect the macroscopic electromagnetic properties of material.The selection,design,and application of related materials and devices in the electromagnetic field must be based on the electromagnetic parameters of materials in the working frequency band.The numerical iterative method is an important method to inverse and calculate the complex permittivity of material.But there always exists a difficult problem that the initial value of iteration is difficult to give accurately.Based on the relationship between the complex permittivity and the reflectivity of absorbing material,an initial value selecting method for iteration to invert permittivity of absorbing material is proposed in this work.For absorbing materials with arbitrary thickness at a certain frequency,the complex permittivity must be near the complex permittivity of perfect matching layer.Therefore,the permittivity of perfect matching layer can be used as the initial value of the iterative algorithm.On this basis,a method of calculating the complex permittivity of monolayer absorbing material by using the reflection parameter is constructed.The experimental results show that the complex permittivity of lossy material can be calculated more accurately at the frequency with absorbing performance.However a great error can be caused at the frequency where the reflectivity is close to zero.Based on the iterative solution of the complex permittivity of single-layer absorbing material,a new method of measuring the complex permittivity of material is constructed by combining multi-layer absorbing materials to enhance full-band reflectivity.Given the electromagnetic parameters of other layer materials,the permittivity of absorbing materials and low-loss materials can be obtained accurately.

关 键 词：吸波材料 反射率 复介电常数 S参数反演 

分 类 号：TB34[一般工业技术—材料科学与工程]