表面横波谐振器的仿真与设计

Simulation and Design of Surface Transverse Wave Resonators

针对现有表面横波谐振器设计软件仿真精度不够的问题,通过引入中间栅P矩阵模拟其对声波的反射和声速的调制作用,计算不同占空比栅阵的耦合模参数,在仿真中加入了中间栅周期、分布和换能器占空比等变量,实现了对中间栅、占空比的优化设计。利用寄生电路计算模块,分析了封装寄生参数的影响,进一步提高了仿真精度。利用该法设计了中心频率315 MHz、插入损耗12 dB、品质因数7 000的谐振器。经实验证实,仿真误差小于0.5%,仿真精度满足设计需要。

In order to improve the precise of the design software of surface transverse wave resonator（STWR）,a center grating P matrix was introduced to simulate the effect of center gratings on wave reflection and the modulation of velocity;the coupling-of-modes parameters were computed for different metallization ratios gratings.Then,the variables of center grating period,location and IDT metallization ratio were included in the simulation to optimize their values.The precise of simulation was improved by using parasitic circuits to include the influence of encapsulation.Using the software,a STWR with center frequency of 315 MHz,insertion loss of 12 dB,loaded Q of 7 000 was designed.Experiment results showed that the errors of simulation were less than 0.5%,and the precise of simulation can satisfy the need of device design.