Measurement Of The Dielectric Parameter Of Radio Frequency Material With The Coaxial Method

This dissertation mainly takes dielectric parameter as the research object, expounds the basic measuring principle of transmission/reflection method based on coaxial air line, analyzes the transmission/reflection method of traditional NRW algorithm, and with reference to the relevant literature, sorted out an improved algorithm. The method not only can effectively solve thickness resonance and multi-valued problems in traditional NRW transmission/reflection method, and reduce measurement error of S parameter, but also removed harsh requirements of sample thickness in traditional method. It can be applied to test system of waveguide fixture and coaxial fixture.This dissertation uses three-dimensional electromagnetic simulation software HFSS to solve the scatter parameter and field distribution map of coaxial air line, and then constructs coaxial air line model of filled PTFE and wax, and under the sample thickness range of 0.4cm-2.8cm and the order long is 0.4cm, filled coaxial air line model of two different material is solved by simulation, then the S parameter of different thickness under the condition of same materials and the S parameter of different materials under the same thickness respectively were compared, summed up some rules. Finally, the coaxial air line and coaxial air line filled of PTFE measured S parameter through the vector network analyzer (AV3620), after data processing, it can obtain dielectric parameters, and compared with the results that concluded by improved transmission/reflection method, so as to verify the correctness and reliability of the algorithm.