A New Type 3D Printing Microwave Resonant Cavity for Materials Moisture Sensing

Regardless of agriculture, forestry, mining, animal husbandry, a high-precision, discerning material moisture content sensing system has a wide range of needs. With reference to the microwave detection technology for dielectric coefficient and moisture content of material, we designed a front-end microwave resonant cavity for measuring the moisture content of the material is realized by 3D printing technology, and its function is successfully measured. This article first analyzes the coaxial cavity TEM mode resonance conditions and the calculation method of quality factors. The electromagnetic simulation software (High Frequency Structure Simulator; HFSS) is used for simulation, and the adjustment of the relationship between the size of the resonant cavity and the frequency deviation and the theory of dielectric perturbation are explained. The simulated coaxial resonant cavity is realized by 3D printing technology, and it is loaded with soil with different moisture content to construct a relationship between moisture content and frequency deviation.