采用微扰法测试碳泡沫的电磁参数

利用网络分析仪连接矩形谐振腔组成材料电磁参数微扰法测试系统。由谐振腔微扰理论出发,得到以托管装载小样品测试时复介电常数和复磁导率的计算公式。对碳泡沫进行电磁参数测试。结果表明,随着碳泡沫电导率的增加,其介电常数缓慢增加,电损耗先增加后减小,而磁损耗不断增加。碳泡沫具有介电常数小、电损耗大、随电导率增加而增加的非本征磁损耗,这种独特的电磁损耗特征使得碳泡沫有用作宽频带高温结构吸波材料的可能性。

Measurement of Electro-Magnetic Parameters of Carbon Foams by Perturbation Method With Application of Network Analyzer ReplaceChar1('spanTitle');ReplaceChar('spanTitle');HanderTitle('enTitle','chTitle','enTitle');

Network analyzer was connected with rectangular resonant cavity to build up a perturbation measure-ment system for electro-maguetic parameters of materials. Based on perturbation theory, the measurement equations for the complex-permittivity and permeability of small volume materials loaded into sample holders for measurement were obtained. The electro-magnetic parameters of a novel radar absorbing material, carbon foams, were measured. It shows that the ε_r'and μ_r" value of carbon foams increase gradually with the increase of electric conductivity, while the ε_r"value increases firstly and then decreases. Carbon foams are characterized by small permittivity,large electric loss and extrinsical magnetic loss. The unique electro-magnetic loss characteristics of carbon foams make it possible to be used as structural radar absorbing materials with wide absorbing bandwidth at elevated temperatures.