Microwave Material Electromagnetic Parameter Testing System Based on the Resonant Cavity Method

This paper presents a testing system for electromagnetic parameters of microwave materials based on resonant cavity. The system uses the split cylindrical resonant cavity. The electric field changes when the cavity is loaded with material, then the frequency shift and the quality factor of the resonator are changed. The system deduces the electromagnetic properties repeatedly and presented visualization by graph and list based on the mathematical relationship between the electromagnetic characteristics of the sample and the microwave parameters. The system designs the derivation algorithm of resonance frequency that is more convenient than in the past and simplifies the realization of the measurement process. The measure of multi-mode iteration also improves the measurement precision of material dielectric constant. Multi-threading and custom messages are designed in software, which realize the parallel execution of instrument control and data analysis, and improves the test efficiency. This paper mainly introduces the measurement principle and the implementation scheme and the problems and solutions encountered in the implementation process.