基于闭式谐振腔的一体化介电常数测量系统

Integrated permittivity measurement system based on closed resonant cavity

为替代矢量网络分析仪,形成一套专用于闭式谐振腔的测量系统,本文采用频谱分析仪模块和跟踪发生器模块,基于C++和VISA库函数进行系统控制,使两模块可以同步收发射频信号,实现闭式谐振腔谐振频率和Q值的测量功能,最终实现微波介质材料的介电常数的测量,形成一套一体化闭式谐振腔介电常数测量系统。该系统与矢量网络分析仪对比测量微波介质陶瓷材料K65,介电常数的相对误差为5.5×10^(-3),tanδ的相对误差为-3.74×10^(-2);对比测量材料K35,介电常数的相对误差为-1.69×10^(-3),tanδ的相对误差为1.08×10^(-1)。测量结果相对误差较小,介电常数的相对误差小于0.01,tanδ的相对误差小于0.5,说明一体化介电常数测量系统的测量结果准确,可用于闭式谐振腔方法下的介电常数测量,也可推广用于其他介电常数测量系统。

In order to form a set of measurement system dedicated to the closed resonant cavity to replace the vector network analyzer,the spectrum analyzer module and the tracking generator module are adopted to control the system based on the C++and VISA library functions and achieve the measurement function on the resonant frequency and the quality factor.Thereafter,the dielectric constant of the microwave dielectric material can be calculated,and a set of integrated closed cavity dielectric constant measuring system is formed.The system is employed to measure the microwave dielectric ceramic material K65 compared with the vector network analyzer.The relative error of the dielectric constant is5.5×10^(-3),the relative error of tanδ is -3.74×10^(-2).When measuring material K35,the relative error of the dielectric constant is -1.69×10^(-3),and the relative error of tanδ is 1.08×10^(-1).The relative error of the dielectric constant is less than 0.01,and the relative error of tanδ is less than 0.5,indicating that the measurement results of the integrated dielectric constant measurement system are accurate.It can be used for the dielectric constant measurement by the closed cavity method,and can also be extended to other dielectric constant measurement systems.