基于谐振腔微扰法测量薄膜复电磁参数的基本原理,使用微波网络分析仪和谐振腔,利用虚拟仪器技术,开发了薄膜电磁参数自动测量系统.利用测试系统对FeCo基纳米膜进行了测试,分析了散射参数、信号源频率与Q值、样品超薄特性、热环境和实验操作等因素对测量结果产生的影响,并由此提出了改进谐振腔法的实验方案.提高了测量的精度,复磁导率测试误差低于6%,复介电常数测试误差低于4%.
This research is based on the basic principle of measuring complex electromagnetic parameters of thin films. An automatic measurement system with virtual instrumentation consists of Vector Network Analyzer, personal computer and resonant cavities, was developed for electromagnetic parameters of thin films. A series of FeCo-based nanostructural thin films were measured in the automatic system by using cavity perturbation method. The effects of scattering parameters, such as the signal source frequencies, Q factor, nanostructural thicknesses, heat environment, and operation method, on the measurement results were analyzed. A schedule is proposed to improve cavity perturbation method. The results show that the measurement errors of complex permeability and complex permittivity are below 6 % and 4 %, respectively.