High-sensitivity microwave microfluidic sensor based on improved defected ground structure

Abstract

The invention discloses a high-sensitivity microwave micro-fluidic sensor based on an improved defected ground structure. The high-sensitivity microwave micro-fluidic sensor is a dual-port device. The substrate comprises a top layer, a middle layer and a bottom layer; the top layer comprises a microstrip line, two 50-ohm resistor elements and two SMA connectors, the microstrip line is provided with two notches, the notches are welded by the 50-ohm resistor elements, the microstrip line is provided with an input port and an output port, the input port and the output port are connected with the microstrip line and are used for being connected with the SMA connectors respectively, and the input port and the output port are connected with the SMA connectors respectively. The SMA connector is communicated with the vector network analyzer; the middle layer is a dielectric plate; the bottom layer comprises an improved defected ground structure, the improved defected ground structure comprises a spiral line and a DGS structure, a square ring is arranged between the spiral line and the edge of the DGS structure, a spiral line structure is arranged in the middle of the DGS structure, and PDMS with a microfluid channel formed inside is arranged on the spiral line structure. The sensor is high in sensitivity, wide in measurement range and small in detection error.

Description

Technical field [0001] The present invention relates to the field of microwave technologies, and is specifically based on high sensitivity microwave microwate control sensors that improve defective structures. Background technique [0002] In recent years, microwave sensors have been applied in many measurement and characterization platforms: such as mechanical displacement and rotary sensors, medical applications biosensor, structural health monitoring, solid dielectric properties, and dielectric constant measurements of liquid chemicals. The main advantages compared to other similar products such as optical or microsystems (MEMS) devices are passive, low cost and provide non-invasive detection. The re-dielectric constant is an important physical characteristic, which describes electrical behavior when the material is exposed to an external electromagnetic field, and can be obtained by microwave technology. When the type or concentration of the sample in the sensing area changes...

AI Technical Summary

Problems solved by technology

Because the disturbance will cause the change of the resonant frequency and the quality (Q-factor) factor, we can adjust the position of the sample to control the sensitivity. It is usually easy to achieve high sensitivity, but we can only achieve detection at discrete resonant frequency points

In the off-resonance scenario, changes in transmission and reflection reveal changes brought about by the sample over broadband, but sample and device preparation is rigorous, implying increased cost

Images