中文摘要：

普通单电极叉指换能器由于相邻两个电极反射的波会同相位加强,它的指边缘反射明显,从而在声表面波器件中形成电极内反射干扰。为了尽量减小这种二阶效应,可以采用分裂指叉指换能器（亦称双电极换能器）。该文从场理论出发,得到叉指表面电荷分布函数,通过对电荷分布函数进行傅里叶变换,得到分裂指叉指换能器的一种新的数学解析模型。它可以准确地反映考虑临近效应后分裂指叉指换能器基频和谐振频率响应。

英文摘要：

The strip edge reflections of the ordinary single-electrode interdigital transducer are quite obvious because of the in-phase of the scattered waves induced from two adjacent electrodes. The wave reflections may result in the electrode interaction perturbations in the surface acoustic wave device. The split finger interdigital transducer （also called double finger transducer） can be used to minimize this second-order effect. In this paper, a new algorithm based on the Fourier transform of the surface charge distribution is proposed to analyze the characters of the split finger interdigital transducer. The surface charge distribution is obtained through the field theory. The model can accurately reflect the harmonic as well as the fundamental frequency response of the split finger interdigital transducer with considering neighbor interactions.