压电晶体表面有限孔径源所产生声表面波的衍射场

到目前为止,声表面波有限孔径叉指换能器产生的衍射场一般是用角谱理论来进行唯象分析的,该标量理论的主要近似是忽略了问题的矢量性质,象在光学中那样,假定波场可以用一个标量来描述。
在本文中,利用我们发展起来的压电晶体中弹性波场表面激发的严格矢量理论,给出了声表面波衍射场的全面严格的表叙。
作为例子,对YZ-LiNbO₃进行了数值计算,所得结果跟角谱理论作了比较讨论。

SAW diffraction field generated by a source with finite aperture on a piezoelectric crystal surface

So far, the diffracted SAW field generated by an IDT with finite aperture on a piezoelectric crystal surface is usually analyzed phenomenologically by angular spectrum theory. The main approximation of this scalar theory is ignoring the vector nature of the field and assuming that the wave field can be represented by a scalar as in optics. In this paper, the rigorous vector theory developed previously of the surface excitation of elastic wave field in piezoelectric crystal is used to obtain the SAW diffraction field strictly. As an example, numerical results for YZ-LiNbO₃ are calculated and compared with those obtained from angular spectrum theory.