基于探头导纳模型的复介电常数测量技术

基于开口同轴探头的导纳模型,建立被测材料复介电常数与反射系数之间的数值关系。使用矢量网络分析仪测量探头终端的矢量反射系数,利用虚拟仪器构建可视化界面,通过软件编程反演计算来确定被测介质的复介电常数,并对已知材料的测量值、HFSS软件仿真值、模型理论值对比,能够很好地吻合,验证了该模型的准确性。对一些常见介质及吸波材料进行了测量。本方法具有非破坏性,适于现场测量,而且具有设备简单、操作方便直观、测量精度高等优点。

Measurement Technique of the Complex Permittivity Based on Coaxial Probe Admittance Model

An admittance model based on the opened coaxial probe is proposed to obtain numerical relations between the complex permittivity and the reflection coefficients of the tested material.We obtain vector reflection coefficients of the ending of the probe through the vector network analyzer.Labview is used to construct the visual interface,and the complex permittivity is calculated by software programming.The measures and simulation results of HFSS tally well with the theoretical values,which validates the accuracy and non-destructive property of the proposed model.In addition,the proposed method has many merits such as simple device,easy operability,high measuring accuracy and so on.