Microwave differential sensor based on substrate integrated waveguide reentrant resonant cavity and microfluidic technology

Abstract

The invention discloses a microwave differential sensor based on a substrate integrated waveguide reentrant resonant cavity and a microfluidic technology. The microwave differential sensor comprises two resonant cavities and a microfluidic chip, and each of the two cavities consists of an upper-layer cover plate and a lower-layer bottom plate which are overlapped. The middle dielectric layers of the upper layer cover plate and the lower layer bottom plate respectively comprise a plurality of metal through holes which are connected with the top layer metal layer and the bottom layer metal layer, and the bottom layer metal of the second layer plate and the top layer metal of the third layer plate are etched with feeder lines with gradually changing appearances. An annular groove is formed in each cavity, and a capacitance column is formed in the middle of each cavity and corresponds to a chip micro-channel. And the two cavities are respectively used as a sensing resonant cavity and a reference resonant cavity. According to the sensor, two reentrant resonators are ingeniously and longitudinally combined, a metal wall naturally existing between resonant cavities and a special excitation mode are utilized, and the advantages that the electric fields of the resonant cavities are highly concentrated and the micro-fluidic chip can accurately control trace fluid are combined, the microwave differential sensor which is compact in structure, is not interfered by factors such as temperature and humidity, has mutually independent components, and can be used for liquid dielectric characterization is formed.

Description

technical field [0001] The invention belongs to the field of sensors, and specifically relates to a microwave differential sensor combined with resonant cavity and microfluidic technology. Background technique [0002] With the rapid development of microwave technology in many industries (such as military, medical, food, chemical and meteorology, etc.), various types of radio frequency microwave devices have been gradually developed and applied. The electromagnetic properties of magnetic media materials greatly affect the performance parameters of equipment devices, so the research on the electromagnetic properties of magnetic media materials is very important. [0003] There are many methods used to measure the dielectric constant, which are mainly divided into resonance method and non-resonance method. The most typical method in the resonance method is the resonant cavity method. Most material characterization sensors convert the change in the dielectric constant of the s...

AI Technical Summary

Problems solved by technology

In the existing differential microwave sensors based on the principle of resonance, there are basically the following deficiencies: the coupling between the two sensing elements reduces the sensitivity to small disturbances; most of the resonators are combined in the horizontal direction; in order to The method of expanding the distance between components to avoid coupling between sensing elements makes the relative size of the overall structure larger and makes the structure not compact enough

[0004] In addition, simply placing the two resonant cavities used as reference and sensing vertically is difficult to solve the feeding problem, because the common coplanar waveguide feeder line cannot provide equal power to the two cavities at the same time longitudinally, which will cause the two cavities themselves to be unstable. Balanced, and the direct use of stripline, the actual process can not get a better transmission response

Images