Differential humidity sensor based on substrate integrated waveguide doublere-input resonant cavities

Abstract

A differential humidity sensor based on the substrate integrated waveguide double re-input resonant cavities is characterized in that two re-input resonant cavities are longitudinally combined together, the two cavities are respectively used as a sensing resonant cavity and a reference resonant cavity, and a sensitive material capable of adsorbing the water molecules in the wet air is deposited in a groove area of the sensing resonant cavity; water molecules are diffused into the sensitive material, so that the internal characteristics of the sensitive material are changed, and the interaction between a strong induction electric field and the moisture absorption material is excited in the sensing resonant cavity. In the reference resonant cavity, the interaction between the strong induction electric field and a moist air medium is excited, and by utilizing the metal grid meshes corresponding to the two cavities, a middle air filling type medium substrate and a capacitor column metallization through hole, a high-sensitivity and high-resolution humidity sensor which is compact in structure, through which moist air can freely enter and exit, and by which the up-down circulation performance is strong, water molecules of the moist air can be enriched in the cavity and fully react with the moisture absorption material, and components of the humidity sensor are mutually independent, is obtained.

Description

technical field [0001] The invention belongs to the field of sensors, in particular to a microwave passive sensor suitable for detecting air relative humidity. Background technique [0002] Humidity is an important indicator in environmental quality monitoring. Humidity detection is of great significance in various laboratory and industrial applications, such as electronic equipment manufacturing, food processing, medical storage, pharmaceutical manufacturing, and large-scale equipment operation. higher requirements. Therefore, the development of high-performance humidity sensors has high practical value in many fields. [0003] Traditional humidity sensors such as resistive sensors, capacitive sensors, and piezoelectric sensors work at relatively low frequencies and cannot be directly applied to modern radio frequency sensing and detection systems. In order to solve this problem, researchers have proposed the design scheme of microwave passive humidity sensor in recent ye...

AI Technical Summary

Problems solved by technology

[0005] The invention proposes a differential humidity sensor based on a substrate-integrated waveguide dual-entry resonant cavity, which solves the problem of humid air flowing up and down in the two resonant cavities, keeps the high quality factor characteristics of the resonant cavity well, and realizes the relative humidity of the air. high-resolution detection of

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