中文摘要：

研究了BT-切石英横向场激励（LFE）的耦合特性、声波相速度及其传感器在液体中的敏感性能。理论计算表明，当横向场方向与晶轴z方向垂直时，b模式的LFE耦合系数达到最大值6．68％，a和c模式的LFE耦合系数为0，此时激发的声波相速度也达到最大值5079m／s。实验发现，器件在液体中，具有较高的机械及电特性灵敏度。结果表明，在b一模式LFE耦合系数为0的方向上，器件实际上工作在伪横向场激励模式。

英文摘要：

A BT- cut quartz sensor excited by lateral electric field was studied. Its lateral field excitation（LFE） coupling factor and acoustic wave phase velocity were calculated and its performance for sensing application in liquid was examined. It is found that when the lateral field direction is normal to the crystallographic x-axis, b-mode lateral coupling factor reaches its maximum of 6. 68% while the a- and c-mode LFE coupling factors are zero,and bmode acoustic wave phase velocity is the maximum of 5 079 m/s. Experiments have shown that BT- cut devices have superior mechanical and electric properties in liquid environment. The study suggests that with the b- mode lateral coupling factor being zero, the device is in fact operating in a pseudo- LFE mode.