SAW-IDT波传播分析

Analysis of Propagation or Surface Acoustic Wave Within Interdigital Transducers

分析了声表面波（SAW）叉指换能器（IDT）中波的传播问题。从产生SAW的静电荷分布出发，结合压电材料的各向异性，推导出了叉指上SAW的电势分布及波角谱表达式，引入了波传播损耗因子与修正脉冲响应函数。对具带通频率响应的加权SAW-IDT进行了模拟计算，包括波传播损耗因子与叉指声孔径大小及相互间距离的关系，修正脉冲响应及其频率响应，波传播对等效电路模型参数的影响。最后得到结论。

This paper analyses the propagation of surface acoustic wave within the interdigital transducer, and deduces the distribution of potential distribution and angular spectrum on the IDT, which is based on the distribution of electrostatic fields taking into account of parameters of piezoelectric material. And a loss factor and modified impulse response are proposed. The simulations of a apodized bandpass SAW-IDT are given, including loss factor for different IDT aperture and distance, frequency response of practical impulse response, the parameters of equivalent circuit. At last, the conclusions are given.