Complex Permittivity Test Of Power And Liquid Materials

Powder materials are widely used in the aerospace defense industry and bio-medicine with its unique physical and chemical properties. When required by the subject of microwave desulfurization, this paper researches on the wideband complex permittivity test technology of coal. The coal pulverized materials test, includes two types of material test: powdered materials and liquid materials. By comparing the wideband complex permittivity test methods, the network parameter method is adopted to test the coal pulverized materials, which of high microwave loss.Firstly, based on the physical properties of powder materials, this paper carries out the powder materials test technology research by using transmission and reflection method, combined with the logarithmic law of mixed materials. The wideband complex permittivity test method with slabline fixture is innovative proposed, for testing the powder and liquid materials. This test method not only improves the measurement accuracy, but also simplifies the process of preparation of the test sample. For electromagnetic materials, on the basis of the existing improved transmission and reflection method, the improved method with two standard sample completing test fixture calibration is innovative proposed, combined with the basic principles of traditional transmission and reflection method and matrix theory. The improved test method reduces the system error term, and theoretically improves the test accuracy.Then, this paper develops the coaxial test fixture, and the size of this fixture is the same as APC-7 connector. Furthermore, in the sample standards, the quality ratio of the two materials in mixed material is 2:1. In order to achieve the new wideband test method, this paper designs and produces the slabline test fixture, and designs the Teflon fixture and Teflon plate avoiding liquid materials leak. In the Teflon fixtures, the matching design improves the microwave performance of the test fixture. In the slabline text system, the first we should do is test the no-load slabline test fixture by using two-port calibrated vector network, and then adds the sample to the test fixture. This process reduces the requirements for the sample production, and the test and calibration process avoids the movement of microwave cable and the repeat demolition of microwave connector, improved the reproducibility of the test results.Finally, we use the two test systems to test several materials’ permittivity, such as paraffin, silica powder, coal, ethanol, purified water, chemical material 3-methylthiophene and biomimetic materials, and analysis the error of the test results. The two test systems both meet the following specifications:Test frequency: 0.2 ~ 18GHzTest material: ε_r~’=1~100tanδ=0.001~1Test error:|△ε_r~’/ε_r~’|≤8%|△tanδ|≤18%tanδ+0.005...