声表面波器件PSPICE仿真研究

Study on PSPICE Simulation of Surface Acoustic Wave Device

声表面波(SAW)器件难以直接采用PSPICE仿真,对设计包含SAW器件的电子系统带来障碍,该文研究了应用PSPICE仿真SAW器件的原理,它将叉指换能器1个周期段等效电路的复阻抗采用LC串并联网络等效,应用阻抗理论推导LC串并联网络各L、C值,将各周期段等效电路声学端级联、电端并联,结合输入和输出叉指换能器电端外围连接特性,同时考虑压电基片自由表面SAW损耗小特点导出了自行研制的Y型SAW器件的宏等效电路模型,并给出了PSPICE仿真电路描述语句,该器件幅度特性仿真结果与实测结果基本相近。

As it is difficult to simulate directly surface acoustic wave device（SAWD） through circuit simulators , there is a great obstacle to design electric system involving SAWD. In this paper ,a method to simulate SAWD using PSPICE is proposed, in which complex impedances of equivalent circuits for a pair of interdigital transduce electrodes are equaled by LC networks valued by Forster＇s impedance theory. Considering peripheral circuit of input and output interdigital transducers and less loss of surface acoustic wave in free piezoelectric material surface, Y type SAW device macro model is obtained by cascading acoustic port ,paralleling electrical port of equivalent circuit for a pair of interdigital electrodes. PSPICE description of Y type SAW device is attached and its simulating results are near to measurements.