Study Of Inertial Devices Based On Surface Acoustic Wave Effect

Gyroscope is an important part in the field of vehicle navigation and weapon guidance.The inertial device based on surface acoustic wave gyroscope has the advantages of high impact resistance,high reliability and low cost compared with the traditional MEMS vibratory gyroscope.In this paper,the variation law of surface acoustic wave in the material under the action of inertia force is studied.The resonator structure of the surface acoustic wave gyroscope is simulated by COMSOL software,and the surface acoustic wave gyroscope is fabricated and the performance is measured by the lithography technology.The following conclusions are obtained:Firstly,study on surface acoustic wave characteristics.Through theoretical analysis and MATLAB simulation,it is found that the velocity of surface acoustic wave decreases with the increase of rotation angle.Secondly,based on the COM model,the structure of the interdigital transducer is analyzed,and the admittance characteristics are obtained by using the COM parameter and the P matrix.Secondly,according to the relationship between the velocity and rotation angular velocity,based on the above analysis,the finite element analysis software is used to model and simulate the multi domain coupling of the surface acoustic wave resonator structure based on 128°YX-LiNbO3,The symmetrical mode deformation and antisymmetric mode deformation are obtained,the phase velocity of surface acoustic wave at 128° YX-LiNbO3 is calculated to be 3917m/s,and the electromechanical coupling coefficient is about 4.71%.Analysis of frequency characteristics of surface acoustic wave resonator at 128 YX-LiNb03.It is found that With the increase of the proportion of the interdigital transducer,the characteristic frequency of the symmetric mode and the antisymmetric mode decreases gradually.The thickness of the piezoelectric substrate has little influence on the characteristic frequency when the piezoelectric substrate is larger than one wavelength.The thickness of the metal electrode increases with the variation of 10nm and the thickness of the 1nm,and the characteristic frequency of the symmetric mode is kept constant and the characteristic frequency of the antisymmetric mode is changed 0.002MHz.Secondly,through the frequency response analysis,the relationship between conductance and frequency is obtained.By adding angular velocity,the linear relationship between the frequency and the rotation rate is obtained.Finally,the average thickness of the metal film prepared by photolithography and magnetron sputtering is 150nm,the width of the metal electrode is 12.555?m,and the frequency response is 81.6MHz.The sensitivity of the new type of surface acoustic wave gyroscope along the X axis is 100.44 Hz/deg/s.