Ge Fei, Zhao Liye, Zhang Yang
School of Instrument Science and Engineering, Southeast University, Nanjing 210096, China.
Micromachines (Basel). 2021 Nov 30;12(12):1485. doi: 10.3390/mi12121485.
Surface acoustic wave gyroscopes (SAWGs), as a kind of all-solid-state micro-electro-mechanical system (MEMS) gyroscopes, can work normally under extremely high-impact environmental conditions. Among the current SAWGs, amplitude-modulated gyroscopes (AMGs) are all based on the same gyro effect, which was proved weak, and their sensitivity and intensity of the output are both lower than frequency-modulated gyroscopes (FMGs). However, because FMGs need to process a series of frequency signals, their signal processing and circuits are far less straightforward and simple than AMGs. In order to own both high-sensitivity and simple signal processing, a novel surface acoustic traveling wave gyroscope based on amplitude modulation is proposed, using one-dimensional phononic crystals (PCs) in this paper. In view of its specific structure, the proposed gyroscope consists of a surface acoustic wave oscillator and a surface acoustic wave delay line within a one-dimensional phononic crystal with a high-Q defect mode. In this paper, the working principle is analyzed theoretically through the partial wave method (PWM), and the gyroscopes with different numbers of PCs are also designed and studied by using the finite element method (FEM) and multiphysics simulation. The research results demonstrate that under a 1 V oscillator voltage output, the higher sensitivity of -23.1 mV·(rad/s) in the linear range from -8 rad/s to 8 rad/s is reached when the gyro with three PC walls, and the wider linear range from -15 rad/s to 17.5 rad/s with the sensitivity of -6.7 mV·(rad/s) with only one PC wall. Compared with the existing AMGs using metal dots to enhance the gyro effect, the sensitivity of the proposed gyro is increased by 15 to 112 times, and the linear range is increased by 4.6 to 186 times, even without the enhancement of the metal dots.
表面声波陀螺仪（SAWGs）作为一种全固态微机电系统（MEMS）陀螺仪，能够在极高冲击的环境条件下正常工作。在当前的表面声波陀螺仪中，幅度调制陀螺仪（AMGs）均基于相同的陀螺效应，而该效应已被证明较弱，并且它们的灵敏度和输出强度均低于频率调制陀螺仪（FMGs）。然而，由于频率调制陀螺仪需要处理一系列频率信号，其信号处理和电路远不如幅度调制陀螺仪直接和简单。为了兼具高灵敏度和简单的信号处理，本文提出了一种基于幅度调制的新型表面声波行波陀螺仪，该陀螺仪采用一维声子晶体（PCs）。鉴于其特定结构，所提出的陀螺仪由一个表面声波振荡器和一个位于具有高Q缺陷模式的一维声子晶体内的表面声波延迟线组成。本文通过分波法（PWM）从理论上分析了其工作原理，并使用有限元法（FEM）和多物理场仿真对具有不同数量声子晶体的陀螺仪进行了设计和研究。研究结果表明，在1V振荡器电压输出下，具有三个PC壁的陀螺仪在-8rad/s至8rad/s的线性范围内达到了更高的灵敏度，为-23.1mV·(rad/s)，而仅具有一个PC壁的陀螺仪在-15rad/s至17.5rad/s的较宽线性范围内，灵敏度为-6.7mV·(rad/s)。与现有的使用金属点来增强陀螺效应的幅度调制陀螺仪相比，即使没有金属点的增强，所提出的陀螺仪的灵敏度提高了15至112倍，线性范围提高了4.6至186倍。
