System and method of testing complex dielectric constant of material based on gradient coaxial resonator

Abstract

The invention provides a system and method of testing complex dielectric constant of a material based on a gradient coaxial resonator. The system comprises the gradient coaxial resonator and a coupling device. The method comprises the steps: 1) testing and recording resonant frequency f0 and quality factor Q0 in a corresponding cavity working mode when no sample is loaded; 2) measuring diameter DSand thickness dS of a sample under test, placing the sample in a sample area, and testing and recording resonant frequency fS and quality factor QS in the corresponding cavity working mode when the sample is loaded; 3) using resonator perturbation theory to calculate complex dielectric constant of the material under test. The system and method have the advantages that high-precision testing of complex dielectric constant at normal temperature is achieved for a microwave dielectric material, required cavity size and sample size for low frequency testing can be reduced, a sealed-bottom tube clamp can also be used to test the complex dielectric constant of liquid and powdery materials.

Description

technical field [0001] The invention belongs to the technical field of testing the dielectric properties of microwave materials, and in particular relates to a testing system and method for the complex dielectric constant of dielectric materials based on a tapered coaxial resonant cavity. Background technique [0002] With the rapid development of high-speed signal processing, communication and other technologies, in military equipment, aerospace, radar stealth, microwave integrated circuits and many other fields, high-performance microwave materials are used as electromagnetic wave transmission media, and their applications are becoming more and more extensive. In the evaluation of the dielectric properties of microwave materials, the complex permittivity is an extremely important electrical performance parameter, and its accurate measurement is essential. Usually the complex permittivity adopts ε=ε 0 (ε'-jε")=ε 0 ε'(1-jtanδ), which are the two most basic characteristic p...

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Problems solved by technology

Japan's Ryotaro Inoue and Yasuhiko Odat et al. proposed a method for testing the complex permittivity of dielectric materials using a coaxial open resonator, but this method has high operating requirements for testers, and the sample is placed above the fixture. The random state has a great influence on the result

Bogdan A.Galwas et al. directly extend the length of the outer conductor of the coaxial line to achieve the effect of open circuit at the terminal, thus forming a λ / 4 coaxial resonant cavity for testing. This method requires a large lateral dimension, a narrow test frequency band, and the need Adding a piece of material with a known dielectric constant will increase the error term, which is difficult to deduct

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