Analysis and comparison of langasite versus quartz for a thickness shear vibratory gyroscope

In our previous work an AT-cut quartz plate with lateral tines was proposed as an angular velocity sensor. The plate itself formed the driving component while the lateral tines formed the angular velocity sensors. The separation of the driving component from the sensing component allowed for a wider variety of tine geometries and modes for detecting angular velocity. In this work we analyze and compare the use of langasite versus quartz for the gyroscope. Since the langasite has a higher (2.17 times) mass density, and a higher (2.26 times) electromechanical coupling constant than those of quartz, the lateral tines were found to be more sensitive to a given angular acceleration. Our analysis showed that the material langasite was better suited for the thickness shear mode angular velocity sensor. Another important advantage for using langasite would be when the gyroscope was needed to operate at a high temperature environment unsuitable for quartz. Strong gyroscopic responses are also a function of the tine geometry. A careful selection of the tine geometry will yield stronger responses to angular velocities. Responses to angular velocities about the three axes (X-, Y-, and Z-axes) could be obtained by using different tine geometries. Hence it is possible for the thickness shear vibratory gyroscope to sense angular velocities about the three axes using multiple tines of various geometries.