A Reentrant Cavity Sensor for Measuring Permittivity and Permeability of Magnetic Media Materials

Abstract

A reentrant cavity sensor for measuring the permittivity and permeability of magnetic medium materials, including a resonant cavity and a coplanar waveguide feeder. The resonant cavity is composed of four dielectric substrates stacked vertically, and each dielectric substrate is provided with a plurality of metallized through holes to form the metal boundary of the resonant cavity. The metal layers between the second and third dielectric substrates are etched with a long groove. A non-metal through hole is etched through each of the dielectric substrates as a dielectric constant sensing area, and a long groove is etched in each of the dielectric layers of the third and fourth dielectric substrates as a magnetic permeability sensing area. The powder sample is loaded in a polytetrafluoroethylene tube and placed in two sensing areas for measurement. The invention applies the folding technology to the substrate-integrated waveguide re-entrant resonant cavity, reduces the size, and improves the quality factor of the resonant cavity through weak coupling feeding, and introduces a complex permeability sensing area in the strong magnetic field area of ​​the resonant cavity, A compact, easy-to-process and integrated multifunctional sensor that fully characterizes the magnetic and dielectric properties of magnetic powders is obtained.

Description

technical field [0001] The invention belongs to the field of sensors, in particular to a microwave passive sensor suitable for measuring the complex permittivity and complex permeability of magnetic powder. Background technique [0002] With the development of microwave technology in many fields (military, medical, food, metallurgy, etc.), various high-frequency devices have been developed and applied, and a variety of new magnetic dielectric materials have emerged in various industries, and the demand for the measurement of magnetic and electrical characteristics of materials has continued to increase Big. The ferroalloy industry has always been a high-energy-consuming industry. The traditional metallurgical ironmaking method has low thermal efficiency and produces a lot of environmental pollution. As a new metallurgical technology, the microwave heating reduction of metal oxide ore has the advantages of high energy utilization rate, fast reaction rate and less environment...

AI Technical Summary

Problems solved by technology

However, the multifunctional sensors reported so far still have the problem that the separation effect of the electric field and the magnetic field is not good, and the measurement of the dielectric constant of the magnetic material is affected by its own high magnetic loss, resulting in a large error.

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