Finite Element Analysis of the Distribution Parameters of a Metal Dot Array in a SAW Gyroscope

Abstract

A surface acoustic wave (SAW) gyroscope has many unique advantages, but a low detection sensitivity limits its development. Previous studies have shown that adding a metal dot array to the acoustic wave propagation path of the SAW delay line can enhance the Coriolis force and further improve sensitivity. Therefore, in order to optimize the detection sensitivity performance of the sensor, 128°YX-LiNbO3, ST-X Quartz and X112°Y-LiTaO3 piezoelectric substrates were selected by finite element method to analyze the influence of the metal dot array size on the SAW gyroscopic effect in this paper. The most suitable metal dot size for 128°YX-LiNbO3 and X112°Y-LiTaO3 obtained by simulation are 5/16λ and 1/16λ, respectively; for example, when the normalized angular velocity is 1 × 10−3, the SAW gyroscopic effect factor g of the two piezoelectric substrates distributing the optimum size metal dots can reach 22.4 kHz and 5.2 kHz. For ST-X quartz, there is a threshold between the rotation speed of the substrate and the optimum size of the metal dot. When the rotating speed is lower than the threshold, the SAW gyroscopic effect is strongest when the metal dot size is 3/16λ; otherwise, the SAW gyroscopic effect is strongest when the size is 11/16λ. These research results provide new ideas for improvement of the SAW gyroscope.