乐甫波器件适于液体检测，但在工程上经常因为激发效率较低而影响应用。与“压电基底-非压电薄膜”的单压电结构乐甫波器件相比，双压电结构的特点是薄膜也选用压电材料，以期增大器件整体的压电效应。在建立理论模型的基础上，通过空气中和液体检测时双压电结构乐甫波与声表面波、单压电结构乐甫波的机电耦合系数仿真并对比，表明对于某些压电基底和薄膜，双压电结构具有更高的乐甫波激发效率。并且，以液体介电常数检测为例，仿真结果还表明了双压电结构乐甫波比单压电结构具有更高的灵敏度。%Love wave device is suitable for liquid measurement,but its low excitation efficiency in the liquid envi⁃ronment hinders its engineering applications. Compared with the“piezoelectric substrate-non-piezoelectric film”Love wave device with single piezoelectric structure,the peculiarity of the Love wave device with double piezoelec⁃tric structure is to use the piezoelectric film besides the piezoelectric substrate,which might enhance the piezoelec⁃tric effect of the device. Based on the establishment of the Love wave theoretical model in the air and with liquid loading,we compare the electromechanical coupling coefficient of the Love wave in the double piezoelectric struc⁃ture with that in the single piezoelectric structure and the corresponding surface acoustic wave,which shows that the device with double piezoelectric structure utilizing some certain piezoelectric substrate and film has higher excita⁃tion efficiency. Moreover,the simulation results also show that the Love wave device with double piezoelectric struc⁃ture has higher sensitivity in the case of liquid dielectric constant measurement.
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