磁性薄膜复数磁导率的短路微带线法测试

Complex permeability measurement of magnetic thin film by shorted microstrip method

基于传输线理论提出了测试磁性薄膜复数磁导率的短路微带线法,利用磁性薄膜标准Lorentzian形式的复数磁导率频谱验证了短路微带线法的正确性。结果表明,短路微带线法在DC^5GHz的频率范围内具有较高的精确性。同时设计和制作了DC^5GHz的测试夹具,用其测试了NiFe磁性薄膜的复数磁导率并用标准Lorentzian形式磁谱对测试结果进行数据拟合。结果表明,从所设计的微带夹具测得的S11能够较为精确地获得磁性薄膜的复数磁导率。最后分析了该测试方法的测试误差来源。

The shorted microstrip method is proposed to test complex permeability of magnetic film based on transmission line theory, and was verified by using standard Lorentzian form complex permeability spectrum of magnetic thin film. The results show that the shorted microstrip method exhbits a high accuracy in DC-5GHz frequency range. A DC-5GHz test fixture was designed and fabricated,and was used to measure the complex permeability of NiFe magnetic thin film and the test tesults was fitted by standard Lorentzian form permeability spectrum. The results show that the test fixture can be used to extract the accurated permeability of the film from the measurement of S11. Also, possible error sources of the method were discussed.