横向电场激励的LiNbO3压电谐振器的仿真分析

Simulation Analysis of LiNbO3 Piezoelectric Resonators Excited by Lateral Electric Fields

该文对横向电场激励下的(yxl)-58°LiNbO3压电谐振器的高频振动进行了研究。首先,基于Mindlin一阶板理论,计算了压电谐振器的模态频谱关系,得到晶体基板长厚比;然后,利用有限元分析软件COMSOL Multiphysics建立了谐振器的三维有限元模型,通过增加厚度方向网格扫掠层数的方法,验证了仿真模型的网格无关性;其次,通过特征频率计算与频域计算得到了谐振器一阶厚度剪切模态频率值;最后,通过改变电极与晶体板质量比以及电极间距的大小,获得了不同尺寸参数对谐振器高频振动特性的影响规律。仿真分析结果表明,电极与晶体板的质量比同谐振器谐振频率成负相关,质量比越大,谐振频率越小;电极间距值与谐振频率成负相关,间距值越大,谐振频率越小。

In this paper, the high-frequency vibrations of ( yxl )-58°LiNbO 3 lateral electric fields(LFE) resonators are studied. Firstly, based on Mindlin’s first-order plate theory, the modal spectrum relationship of piezoelectric resonator is calculated, and the length-thickness ratio of crystal substrate is obtained. Then, the three-dimensional finite element model of the resonator is established by using the finite element analysis software COMSOL Multiphysics. By increasing the thickness direction grid to sweep the layer number, the grid-independence of the simulation model is verified. Besides, the characteristic frequency calculation and frequency domain calculation are carried out to obtain the first-order thickness-shear mode vibrations frequency value. Finally, by changing the mass ratio of the electrode to the crystal plate and the size of the electrode spacing, the influence of different size parameters on the high-frequency vibration characteristics of the resonator is obtained.