Development of High-Level Design System for Raising the Performance of Surface-Acoustic-Wave Devices

声表面波（surface acoustic wave）器件设计CAD系统的性能受到仿真程序精度的限制。SAW器件的精确模拟必须考虑纯电、声学和混合电声效应。本课题的目的是为各种SAW器件开发一个高层次的设计系统。实验结果如下：1。本文提出了一种基于有限元法的任意形状周期SAW波导的数值分析方法，该方法经常出现在实际的SAW器件中，如SAW数字间换能器（IDT）、SAW反射器和SAW谐振器。建立了等效网络理论和耦合模式理论，用于分析SAW- idt的激励特性和SAW qratings的反射特性。等效网络的电路参数和耦合模式方程的耦合系数和转导系数可以通过对电短路或开路IDT对应的无限阵列应用有限元法从理论上确定。本文还采用有限元法计算了一对IDTs.3的静电容。提出了一种基于有限元法的静磁波在YIG薄膜中传播的统一数值方法。

The performance of a CAD system for the design of SAW (surface acoustic wave) devices is limited by the accuracy of the simulation procedure. A precise simulation of SAW devices must take into account pure electric, acoustic, and mixed electroacoustic effects. The purpose of this project is to develop an high-level design system for various SAW devices. Results obtained are as follows:1. A numerical approach based on the finite element method has been developed for the analysis of arbitrarily shaped periodic SAW waveguides which frequently appear in the actual SAW devices, such as SAW interdigital transducer (IDT), SAW reflector, and SAW resonator.2. An equivalent network theory and a coupled mode theory are developed for the analysis of excitation characteristics of SAW-IDT and of reflection characteristics of SAW qratings. Circuit parameters of equivalent networks and coupling and transduction coefficients of coupled mode equations can be theoretically determined by applying the finite element method to an infinite array corresponding to an electrically shorted or open IDT. The finite element method is also used to calculate the static capacitance for one pair of IDTs.3. A unified numerical approach based on the finite element method is developed for the magnetostatic wave propagation in a YIG film.