Study On High Temperature Pressure SAW Sensor Based On LGS

This paper presents a3 5 14 La Ga SiO(LGS) based Surface Acoustic Wave(SAW) high temperature pressure sensor for the high temperature pressure measurement. In theory, this study combines the electro elastic perturbation theory and finite element method, calculated the stress and strain field of LGS piezoelectric substrate under the pressure by the finite element method, then obtained the effective material constants and additional material constants of the LGS piezoelectric substrate in the temperature partial load condition and the pressure perturbation condition by using the results of stress and strain field, finaly obtained the pressure sensitivity of the LGS piezoelectric substrate by appling the result of effective material constants and additional material constants to electro elastic perturbation equation with partial load. According to the solved pressure sensitivity of the(0,0,x) cut LGS electric substrate of each SAW propagation direction on temperature of 300℃, the LGS substrate with Euler angles for(0, 0, 90) was selected as the high temperature pressure sensor substrate. And the calculated double channel pressure sensitivity of the sensor in theory is 278ppm/MPa. Based on the above theoretical analysis, a(0, 0, 90) cut LGS based high temperature pressure SAW sensor of point type pressure transfer structure was made.And the study also builded high temperature pressure test environment, tested the pressure response of sensor in the temperature range of-55℃ to 320℃. The experimental results agree well with the theoretical analysis...