Evolution and Analysis of Dielectric Properties of Typical Materials Under Strong Microwave Field

The complex dielectric constant is the intrinsic parameter of microwave material, and the accurate acquisition of its value is critical for its application. Generally, the dielectric properties of microwave materials are obtained under weak electromagnetic field. However, with the continuous development of high power microwave technology, the microwave field intensity around materials gradually increases, and the test results of the dielectric properties of materials under the weak electromagnetic field will not be able to characterize the test results under the high power environment. Therefore, a novel testing technology based on the resonator method is proposed, which provides an effective solution for the measurement and characterization of microwave dielectric properties of materials under strong microwave field. Based on the constructed system, the evolution rules of the microwave characteristics of four typical materials are obtained. In the experiment, the temperature of the samples is precisely monitored, and the evolution rules of the temperature characteristics of the dielectric properties of the samples under strong and weak microwave fields are compared. The comparison results demonstrate that the dielectric properties of materials under strong fields are related not only to the microwave heating effect but also to the mechanism of the non-thermal microwave effect.