Microwave sensor based on double-reentrant cavity and microfluidics technology

Abstract

The invention discloses a microwave sensor based on double-reentrant cavity and microfluidics technology. The microwave sensor comprises a substrate integrated waveguide double-reentrant cavity and amicrofluidic chip embedded in the resonant cavity; the resonant cavity is composed of an upper cover plate or a lower baseplate in lamination; each of the upper cover plate and the lower baseplate comprises a top metal layer, a middle medium layer and a bottom metal layer; the middle medium layer of each of the upper cover plate and the lower baseplate comprises a plurality of metal through holesfor connecting the top metal layer and the bottom metal layer; an annular groove is formed on the lower baseplate, two symmetric capacitive posts are arranged in the groove. The microfluidic chip is embedded into the substrate integrated waveguide double-reentrant resonant cavity, the tested liquid-state dielectric medium is precisely loaded in the microfluidic, and a non-intrusive, reusable and high-sensitive multi-band liquid-state medium dielectric characteristic sensor which is easily nitrated with other plane circuit is realized by utilizing a mutual mechanism of action of the resonant-cavity-excited three-band strong-induced electric field and the dielectric medium polarization.

Description

Technical field [0001] The invention belongs to the field of sensors, and particularly relates to a microwave sensor suitable for detecting liquid media. Background technique [0002] Current microwave sensing and detection methods for liquid media are usually divided into non-resonant transmission method and resonance method. Compared with non-resonant transmission method, resonant method has significant advantages such as high Q value and controllable resonance frequency. By using its resonance frequency The point shift and the phase amplitude change of the scattering parameters can realize the accurate measurement of the dielectric constant of the medium. Therefore, the detection technology scheme based on the microwave resonance mechanism has become a research hotspot and has attracted wide attention from scholars at home and abroad. [0003] However, with the continuous development of modern detection technology, microwave sensing test systems tend to be miniaturized and inte...

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Problems solved by technology

For the single-frequency point measurement method, because different mixtures may have the same frequency shift, the measurement at a fixed frequency can only distinguish chemicals by frequency shift, which limits the reliability of measurement identification, that is, because different chemicals in the same Measurements within a frequency band may have the same frequency shift, so it is not reliable to judge chemicals based only on the shift of frequency points within a frequency band

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