横向场激励的压电体声波器件高频振动分析

发布时间：2018-05-16 14:16

本文选题：横向场激励 + 谐振器　；参考：《宁波大学》2017年硕士论文

【摘要】：横向场激励是一种新的激励模式,不同于传统的厚度场激励模式,其电极位于晶体板的同一表面上。这种新型激励模式相比于厚度场激励模式具有很多优势,如品质因数值高、频率稳定性好、晶体老化率低等特点。有关横向场器件声波振动分析方法的研究成果还非常缺乏,直接影响到器件最佳设计参数的确定。本文中以横向电场激励的非理想电极慢剪切模态石英晶体谐振器为研究对象。主要完成了以下工作:基于Mindlin板理论推导了横向场激励的板方程,对方程组进行截断,忽略掉高阶位移与电势,保留零阶与一阶项,得到考虑能量耗散的横向场激励石英晶体的一阶板方程;利用横向场激励的一阶板方程对晶体板的自由振动进行了分析,得到其电极区和非电极区的色散关系;考虑厚度扭曲振动与面剪切振动的耦合,求得了横向场激励石英晶体板振动时的频谱关系,即频率和板长/厚比的关系;对横向场激励的石英晶体板进行了受迫振动分析,得到其动态电容与谐振频率的关系;通过分析各谐振模态的厚度扭曲与面剪切振动耦合情况,确定了符合良好能陷特性的谐振模态;最后分析了不同器件参数,如电极间距值、电极尺寸、电极质量比R等对器件振动特性的影响。然后设计并制作横向场器件,通过测试器件的阻抗特性,对理论结果进行了验证。研究结果可为横向场激励石英体声波器件的尺寸参数设计提供理论依据,对利用横向场器件研制高性能谐振器和传感器具有积极促进作用。
[Abstract]:Transverse field excitation is a new excitation mode, which is different from the traditional thickness field excitation mode, and its electrode is located on the same surface of the crystal plate. Compared with the thickness field excitation model, this new excitation mode has many advantages, such as high quality, good frequency stability and low aging rate. The research results on acoustic vibration analysis of transverse field devices are still very scarce, which directly affect the determination of the optimum design parameters of the devices. The slow shear mode quartz crystal resonator with non-ideal electrode excited by transverse electric field is studied in this paper. The main works are as follows: based on the Mindlin plate theory, the plate equation of transverse field excitation is derived, the equations are truncated, the higher-order displacement and potential are ignored, and the zero-order and first-order terms are retained. The first order plate equation of quartz crystal excited by transverse field with energy dissipation is obtained, the free vibration of crystal plate is analyzed by the first order plate equation excited by transverse field, and the dispersion relation between the electrode region and the non electrode region is obtained. Considering the coupling of thickness torsional vibration and plane shear vibration, the frequency spectrum relation of quartz crystal plate excited by transverse field is obtained, that is, the relation between frequency and length / thickness ratio, and the forced vibration of quartz crystal plate excited by transverse field is analyzed. The relationship between the dynamic capacitance and the resonant frequency is obtained. By analyzing the coupling of thickness distortion and plane shear vibration of each resonant mode, the resonant mode with good energy trapping characteristics is determined. Finally, different device parameters, such as electrode spacing, are analyzed. The effect of electrode size and electrode mass ratio R on the vibration characteristics of the device. Then the transverse field devices are designed and fabricated, and the theoretical results are verified by testing the impedance characteristics of the devices. The results can provide a theoretical basis for the design of dimension parameters of quartz bulk acoustic devices excited by transverse field, and can promote the development of high performance resonators and sensors using transverse field devices.
【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN65

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