The Broadband Microwave Characteristic Parameters Of Dielectric Material Automated Test Improvements In Technology

The accurate measurement of the solid material’s complex permittivity is importantfor the widespread application of microwave dielectric material. The electricalcharacteristics of dielectric material are the indispensible information for investigationand application. There are many measure methods of complex permittivity, which is thebasic parameter of the characterization of the dielectric material. The thesis is focusedon the optimization and improvement with the high-Q cavity measurement systembased on GB/T5597-1999and the strip line measurement system based on GB/T12636-90.The principle of original GB/T5597-1999based on high-Q resonator with TE_01pmode is using a variable length cavity to fix the resonator before/after placing thesamples to calculate the complex permittivity. The theses introduces a multimode cavitymeasurement system with fixed length to achieve18⁴0GHz broadband. This work isbased on previous mode purifying research to improve suppress interference mode ofTE_01phigh-Q resonator. According to the field characteristics of TE_01pmode, the cavityused matured non-contact piston type divided into three parts: the main cavity, thepiston and the rear cavity with absorb material inside to further attenuate theinterferential mode. The simulation and optimization on the gap width G of thenon-contact piston cavity with the software HFSS and the coupling structure areanalyzed and discussed. The Q value measurement method was researched andimproved to improve the system’s accuracy. The automated testing software wasdesigned with SICL （Standard Instrument Control Library） by the C++language,applying the mode search and recognition technology. It’s automated, fast and accurate.Finally, a sapphire material sample was measured with the system and obtained asatisfied result.The strip line resonator theory and the principle of strip line measurement systembased on GB/T12636-90are analyzed. The fixture was re-designed to enhance theinterference rejection with external force. The improvement of coupling devices makethe coupling coaxial can be adjusted in two-dimension to adjust the coupling parameter, while the stability of the system was improved. The pressure sensor component wasoptimized with high precision weighing measurement analog to digital convertermodule, and embedded in measurement software interface shows the pressure using thecomputer’s serial communication with user convenience. The friendly automatedmeasurement software was finished with the Agilent’s SICL through VC++. The systemis used for measure the sample from a renowned institute, and the results indicated thesystem’s stability and repeatability excellent, corresponding the specification andsatisfactory.