Stimulation and vibration pick integrated pressure sensor of electric heating stimulation-piezoresistance vibration pick resonance beam

Abstract

The invention discloses a stimulation and vibration pick integrated pressure sensor of an electric heating stimulation-piezoresistance vibration pick resonance beam, which comprises a pressure sensing membrane, a two-end fixed and supported resonance beam, a stimulation-vibration pick resistor and a phase-locked closed-loop circuit, wherein a measured pressure directly acts on the lower surface of the pressure sensing membrane and enables the pressure sensing membrane to deform. The deformation of the pressure sensing membrane causes an internal stress of the two-end fixed and supported resonance beam fixed on the upper surface of the pressure sensing membrane to change, and then a first-order natural frequency of the resonance beam is changed. The measured pressure can be measured through tracking the change of the first order natural frequency of the resonance beam. According to the stimulation and vibration pick integrated pressure sensor, a stimulation resistor and a vibration pick resistor are combined into the simulation-vibration pick resistor, thus the structure is simplified, and the vibration pick signal frequency is three times of the stimulation signal frequency, a vibration pick signal and a stimulation signal are separated in a frequency domain, the problem of co-frequency capacitance coupling interference is better solved, and the natural frequency drift of the resonance beam due to a resistor electrocaloric effect is greatly reduced.

Description

technical field [0001] The invention belongs to the technical field of micro-electromechanical systems, and relates to an electrothermal excitation-piezoresistive vibration pickup resonant beam pressure sensor that combines excitation and vibration pickup. Background technique [0002] Silicon microresonant pressure sensors are widely used in industrial automation, instrumentation and other fields due to their excellent resolution, stability, repeatability and easy interface with computers, especially for aviation atmospheric pressure test systems. figure 1 It is a schematic diagram of the sensitive structure of a typical electrothermal excitation-piezoresistive pickup resonant beam pressure sensor, which mainly includes a pressure sensitive diaphragm 1, a double-end fixed support resonant beam 2, an excitation resistor 5 and a pickup resistor 6. The measured pressure acts on the pressure-sensing diaphragm 1 and causes it to deform. The deformation of the pressure-sensing di...

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Problems solved by technology

[0004] The technical solution problem of the present invention is: in order to solve the same-frequency capacitive coupling interference problem of the excitation resistance to the vibration pickup resistance in the existing electrothermal excitation-piezoresistive vibration pickup resonant beam pressure sensor and reduce the natural frequency drift of the resonance beam caused by the resistance electrothermal effect, However, the excitation resistor and the vibration pickup resistor are combined to propose an electrothermal excitation-piezoresistive vibration pickup resonant beam pressure sensor that combines excitation and vibration pickup.

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