IDT在YZ-LiNbO_3基片上的体声波激励研究

Research on IDT Excitation of Bulk Waves on YZ LiNbO 3 Substrate

具有广泛应用前景的声板波液体密度传感器采用了叉指换能器（ＩＤＴ）在基片上的体声波（ＢＡＷ）激励效应。文章针对常见的ＹＺ－ＬｉＮｂＯ３基片，研究了ＩＤＴ激励ＢＡＷ的响应与激励频率之间的关系。压电基片表面的ＩＤＴ激励的ＢＡＷ在基片内来回反射，选择恰当的ＩＤＴ激励频率，可得到极大的ＢＡＷ响应。实验结果和理论分析表明，ＢＡＷ的极大响应与发射接收ＩＤＴ的间距、基片厚度和激励频率有确定关系。

An APM (acoustic plate mode) liquid density sensor with vast application prospects employs the excitation effects of bulk acoustic waves (BAW) on the substrste In the present paper, the relations between BAW excitation rsponse by interdigital transduce (IDT) and BAW excitation frequency are studied for the commonly used substrate: YZ LiNbO 3 BAW excitation by IDT positioned on the surface of the substrate is reflected back and forth in the substrate, and the maximum response of BAW can be obtained by properly choosing the excitation frequency The experimental results and theoretical analysis show that there exist definite relations among the distance of two IDTs, the thickness of the substrate and the excitation frequency