Research On Optimal Design And Temperature Decoupling Of Pressure Sensors Based On Surface Acoustic Wave Technology

At present,in systems with a high degree of automation and complexity,such as aeroengine and aircraft design,the accuracy,reliability,and dynamic response sensitivity of pressure sensors are getting higher and higher.Surface Acoustic Wave(SAW)pressure sensors rely on surface acoustic wave technology,which has the advantages of high sensitivity,high reliability,and strong adaptability to the environment,and can be used for passive wireless monitoring,so it is widely used in various fields in.However,due to the high temperature environment,the detection performance of the surface acoustic wave pressure sensor itself will cause detection errors due to the temperature drift effect,thereby affecting the accuracy of the detection results.Therefore,in response to the above problems and the urgent need for surface acoustic wave pressure sensors in practical applications,this article optimizes the design of surface acoustic wave pressure sensors to improve their adaptability to high temperature(150～500℃)environments and high stability(frequency temperature).Coupling coefficient TGF<20ppm/℃),to improve the temperature-to-temperature error caused by the pressure sensor’s monitoring results,has important research significance.First,according to the basic structure and working conditions of the SAW sensor,the basic parameters such as the structure and film structure of the sensor,the interdigital transducer and the acoustic reflection grid were selected;a three-dimensional model of a single pair of interdigital electrodes was established through COMSOL Multiphysics,The resonant frequency simulation was carried out,and the resonant frequency and resonant mode diagram of the sensor were obtained,which verified the propagation characteristics of surface acoustic waves;at the same time,based on this model,different piezoelectric layers,electrode layers and substrate thicknesses and interdigital electrode metallization were studied.The change of the sensor’s detection performance caused by the rate is analyzed,and its influence on the SAW sensor’s resonant frequency is analyzed.According to the analysis,the structural parameters of the SAW sensor are optimized.Then,combined with the optimized mechanism parameters,a three-dimensional model of the surface acoustic wave sensor sensor chip is established,and its resonance frequency is simulated,and its resonance frequency,energy,and stress distribution are obtained;based on this model,different temperatures and The pressure conditions were analyzed,and the coupling effect between temperature and pressure was studied;the temperature drift effect caused by temperature on the sensor chip was analyzed,and the Si O2 film layer was added to correct the temperature frequency coefficient by means of temperature compensation.The different positions and thicknesses are analyzed separately,which effectively reduces the influence of temperature on the performance of the sensor itself.Finally,combining the optimized parameters and the structure after adding temperature compensation,by analyzing the structure of the pressure sensitive membrane and the pressure transmission mechanism,combined with the working principle of the pressure sensor,a three-dimensional model of the basic structure of the SAW sensor is established;by analyzing the stress and Strain distribution,combined with perturbation theory and surface acoustic wave propagation theory,calculated and analyzed the initial frequency and pressure sensitivity of the sensor model,and then constructed a temperature-pressure coupling formula,obtained the pressure sensor detection results in a specific temperature environment,and carried out Specific solution verification.