Low-loss Material Complex Permittivity Testing, Separation Of Dielectric Resonator Method

Microwave dielectric materials have been widely used in information and communication domain, which are used in the systems of microwave communication, satellite communication, electronic countermeasure and so on. Therefore it is highly significant to measure the electromagnetic parameters of medium materials, as knowing the dielectric materials'microwave characteristics is the most important factor in applications.In this paper, the complex permittivity measurement of low-loss materials using dielectric resonator and split post dielectric resonator(SPDR) are researched. Based on analyzing theory of the measurement and deducing the formulas of the complex permittivity, a set of system is built .According to the frequency and the quality factor of the resonator unloaded and loaded, the system can calculate the permittivityεr' and the loss angle tangent tanδof the low-loss material which is tested.The main research work includes:1. Through analyses of the correlative measurement technology and consideration of the characteristic of the measured materials, the method using dielectric resonator and the SPDR is selected; Theory of the dielectric resonator is analyzed; The physical model of the dielectric resonator for measuring is settled; The formulas of the complex permittivity are deduced.2. Feasibility of test model is discussed. Measurement is done to all departments of the system. Finally, the whole system of measurement is built.3. The samples are measured by the system. Matlab is used for processing the frequency and the quality factor .And the error of the system is analyzed and discussed .The complex permittivity of low-loss material which is tested by the system indicates that the method is correct, and the test system is reliable. Therefore, the test technique of using dielectric resonator and the SPDR can be used for measurement of material parameters of dielectric medium, and it is also extraordinary practical.