ZnO/蓝宝石结构声表面波频散特性数值计算

Numerical Calculation of SAW Dispersion Properties Based on ZnO/Sapphire Structure

从理论上计算出ZnO/蓝宝石结构声表面波相速度和机电耦合系数k2色散曲线。计算显示,在ZnO膜厚和声表面波器件波长之比h/λ=0.48时,IDT/ZnO(c面)/蓝宝石(c面)结构西沙瓦波1次模式的k2最大值为2.705%,理论声速为4 982m/s;在h/λ=0.3时,IDT/ZnO(a面)/蓝宝石(r面)结构西沙瓦波1次模式的k2最大值为4.34%,理论声速为5 509m/s。结果表明,IDT/ZnO(a面)/蓝宝石(r面)结构西沙瓦波1次模式的k2和声速较大,适于研制高频低损耗声表面波滤波器。

The dispersion curves such as the phase velocity and electromechanical coupling coefficient（k2）were calculated theoretically in this paper.The result shows that Sezawa wave mode 1on ZnO（c plane）/sapphire（c plane）structure has maximal k2 value of 2.705% and phase velocity 4 982m/s at h/λ=0.48,and Sezawa wave mode 1on ZnO（aplane）/sapphire（r plane）structure has maximal k2 value of 4.34% and phase velocity 5 509 m/s at h/λ=0.3,which means IDT/ZnO（aplane）/sapphire（r plane）structure has higher maximal k2 value and phase velocity of Sezawa wave mode 1.In other words,IDT/ZnO（aplane）/sapphire（r plane）structure is the better choice for designing high frequency and low loss SAW filter.