压电晶体-液体界面上IDT对入射声体波的接收

Detection of Acoustic Bulk Waves by Inte rdigital Transducer at an Interface of Piezoelectric Crystal and L iquid

压电晶体－液体－压电晶体分层结构可用于液体声传感器的研制，两个叉指换能器（ＩＤＴ）分别位于两个相向的压电晶体－液体界面上，一个ＩＤＴ向液体中激励声体波，另一个ＩＤＴ接收液体中的声体波。文章通过采用恰当的压电晶体－液体界面上的边界条件，研究了ＩＤＴ对声体波的接收，给出了ＩＤＴ的输出电功率与声体波入射角、晶体取向之间的关系曲线；此外，还探讨了负载对ＩＤＴ电输出的影响。文章所得结果，为研制液体声传感器奠定了理论基础。

The layered structure c onsisting of piezoelectric crystal liqui d piezoelectric crystal can be employed to develop the acoustic sensor for liqui d.Two interdigital transducers(IDTs)are positione d face to face at the piezoelectric crys talliquid interfaces.The acoustic bulk w aves(ABWs) propagating through the liqui d layer are excited by one IDT,and detec ted by another one.On the basis of the a ppropriate boundary condition of the pie zoelectric crystal liquid interface,we a nalyze the detection of ABWs by IDT and give the relationship curves of the IDT output electrical power versus the ABW incident angle and crystal orientation.M oreover,the influence of the load on the IDT output has also been discussed.The article result lays the theoretical foun dation for developing the applied acoust ic sensor of liquid.