Based Labwindows / Cvi Media Complex Permittivity Measurement System Design

This paper mainly studies the microwave permittivity measurement techniques of dielectric materials based on LABWINDOWS/CVI.As a main function parameter of dielectric material,the measurement methods of permittivity are diverse. This paper used the rectangular waveguide perturbation and short waveguide method to measure the dielectric materials.Firstly, based on the transmission line theory, the microwave theory and the rectan- gular waveguide theory, this thesis discusses the rectangular waveguide perturbation and the short waveguide method. The vector network analyzer is used in the processing of measurement. All kinds of errors existing in the measurement system could result in bias between measuring value and the true value. In order to remove the system errors, the Vector Network Analyzer (or VNA) must be calibrated before measuring the devices under test. The TRL (thru-reflect-line) method is used in this paper.The TRL is a method which uses the Thru,Reflect,Attenuation of network to get rid of the errors of the test network. as the same other methods, the S parameters is used to analyze the TRL. Secondly, based on the theory before, a test system is designed.This system is used to measure dielectric materials based on Labwindows/cvi. Then, the settings and how to using is offered. Some materials were test by using this system. Finally, the research work in the thesis is summarized, and the problems remain to be studied and improved further are pointed out.