改进的谐振腔微扰法测定电介质X波段介电常数

Improved cavity perturbation technique for permittivity measurement of microwave dielectric material at X-band

针对谐振腔微扰法对电介质材料介电性能进行测量时,要求测试过程满足微扰条件,即待测样品的介电常数或体积较小的情况,研究了谐振腔微扰法测试微波材料的原理,通过改变待测样品的体积及标定修正对应的微扰计算公式,使其满足对高介电常数材料的测量.对电介质块材与薄膜样品进行了测量,结果显示,谐振频率偏移小于100MHz,标定的计算公式精度较高.改进后的测量方法可以增大谐振腔微扰法的测量范围,适用于高介电常数陶瓷块材与薄膜的介电常数、介电损耗的微波频率测量.

The demand of perturbation condition must be satisfied when the cavity perturbation method was used for the permittivity （εt） measurement. The theory of cavity perturbation was investigated. The method was improved by changing the volume of the samples and the formula so that it can be used for the high permittivity measurement. The results of the measurement of the bulks and films show that the precision of the improved measurement methods is very high. This measurement is applicable for permittivity and loss tangent measurement of some high permittivity ceramic and film at microwave frequency.