钽酸锂单晶材料的横向场激励特性

Lateral field excitation properties of LiTaO_3 single crystal

用(yxl)-16.51°切型的钽酸锂(LiTaO3)加工制作两个电极在同一基板平面的横向场激励器件来验证该材料的横向场激励特性。理论上用扩展的Christoffel-Bechmann方法计算了LiTaO3材料的横向场激励机电耦合系数,其c模式值最大为37.9%。实验结果表明在空气中横向场激励在5.257MHz频率附近引起了一个明显的谐振主峰,谐振处阻抗为727Ω;在液体中由于液体模拟电极的作用而形成了厚度场激励,使其在5.695MHz附近产生了另外一个谐振主峰。通过对声波相速度和谐振频率的计算也验证了实验结果。

Lateral field excitation （LFE） properties of LiTaO3 single crystal were investigated by using a （yxl）- 16.51° LiTaO3 LFE device with the two electrodes on one major plane of plate and no electrode in other side. The piezoelectric coupling factor of （yxl）-16.51° LiTaO3 was calculated by using the extended Christoffel-Bechmann method and its maximum value of 37.9% for the c mode was achieved in theory. The experiment result shows that there is a significant major peak observed at the frequency of about 5. 257MHz caused by LFE with its impedance being 727Ω in air. However, there is another resonance peak appeared nearly at the frequency of 5. 695MHz in liquid due to the influence of the analogy electrode which is formed by liquid. The above results are also verified by the calculated resonance frequency together with the acoustic wave phase velocity.