Wideband Low-loss Dielectric Microwave Complex Permittivity Testing Technology

Low loss dielectric material is widely used in domestic and military technologies,it is necessary to know the broadband respones of complex permittivity of the low loss dielectric material. The paper analyzes the usual measurement methods of complex permittivity,according to the method of high Q cavity and the technology of multimode in one cavity.The broadband test cavity have been designed,and set up the broadband autotest system. Using the broadband test system and the automatic test software ,the samples are tested ,the complex permittivity of the samples are obtained.The test method of thin sample is analyzed. The measurement errors is analyzed in the paper.The error sources are defined according to the measurement theory,with the analysis of error theory,the measurement errors are obtained. The measurement range and measurement errors of the test system are as follows: Frequency: 7 18 GHz Measurement range: ε' = 2 ⁸ tanδ= 2 ×10^-4 5 ×10^-3 Measurement errors: /Δε'/ε'/≤2% /Δtan δ≤12%tanδ+5 ×10^-5...