互补开口谐振环微带传感器介电常数的测量  

Permittivity Measurement Using the Microstrip Sensor Loaded with a Complementary Split-Ring Resonator

作　　者：孙景芳[1] 李永倩[1] 胡佩佩 张淑娥[1] SUN Jingfang;LI Yongqian;Hu Peipei;ZHANG Shue(School of Electrical and Electronic Engineering,North China Electric Power University,Baoding Hebei 071003,China)

机构地区：[1]华北电力大学电气与电子工程学院,河北保定071003

出　　处：《传感技术学报》2019年第4期532-536,共5页Chinese Journal of Sensors and Actuators

基　　金：国家自然科学基金项目(61775057)

摘　　要：介电常数是材料的重要特性之一,采用互补开口谐振环微带传感器实现了不同厚度待测物质介电常数的无损测量。方形互补开口谐振环蚀刻在微带线接地平面上,与微带线耦合实现谐振,分析了谐振器的等效电路,讨论了介电常数与谐振频率之间的关系。通过有限元分析,谐振频率的负二次方与待测物质的介电常数实部值存在线性关系,且线性关系受待测物质的厚度影响;介电常数的虚部值对谐振频率的影响可忽略不计;最终建立了介电常数实部值与谐振频率和样本厚度之间的数学解析式。实验测试结果表明,当待测样品的厚度大于2 mm时,实部介电常数的相对测量误差小于3.5%。Permittivity is one of the most important parameters of materials;in this work,a microstrip sensor based on a complementary split-ring resonator(CSRR)is proposed for permittivity noninvasive measurement of materials with different thickness. The rectangular CSRR is etched in the ground plane of a microstrip line and is coupled with this line for resonance. The paper analyzes the equivalent circuit of the resonator,discusses the relationship between the permittivity and the resonant frequency. The finite element analysis shows that the negative squared resonant frequency varies linearly with the real permittivity,and the linear relationship is affected by the thickness of the material under test. The effect of the imaginary permittivity on resonant frequency can be ignored. A numerical model is developed for the calculation of the real permittivity as a function of resonant frequency and the thickness of material under test. The numerical model is experimentally verified for various reference samples,it is found that real permittivity measurement using proposed sensor is possible with the relative error of less than 3.5% when the thickness of the material under test is thicker than 2 mm.

关 键 词：微波测量技术 介电常数测量 互补开口谐振环 无损测量 谐振频率 

分 类 号：TM931[电气工程—电力电子与电力传动]