Title :
Exact analysis of dispersive SAW devices on ZnO/diamond/Si-layered structures
Author :
Wu, Tsung-Tsong ; Chen, Yung-Yu
Author_Institution :
Inst. of Appl. Mech., Nat. Taiwan Univ., Taipei, Taiwan
Abstract :
In this paper, a formulation for calculating the effective permittivity of a piezoelectric layered SAW structure is given, and the exact frequency response of ZnO/diamond/Si-layered SAW is calculated. The effective permittivity and phase velocity dispersion of a ZnO/diamond/Si-layered half space are calculated and discussed. The frequency response of an unapodized SAW transducer is calculated, and the center frequency shift caused by the velocity dispersion is explained. In addition, the electromechanical coupling coefficients of the ZnO/diamond/Si-layered half space based on two different formulas are calculated and discussed. Finally, based on the results of the study, we propose an exact analysis for modeling the layered SAW device. The advantage of using the effective permittivity method is that, not only the null frequency bandwidth, but also the center frequency shift and insertion loss can be evaluated.
Keywords :
diamond; frequency response; interdigital transducers; permittivity; piezoelectric thin films; silicon; surface acoustic wave devices; surface acoustic wave transducers; ultrasonic dispersion; zinc compounds; IDT SAW transducer; ZnO; ZnO-C-Si; ZnO/diamond/Si layered structures; center frequency shift; dispersive SAW devices; effective permittivity; electromechanical coupling coefficients; exact frequency response; insertion loss; null frequency bandwidth; phase velocity dispersion; piezoelectric layered SAW structure; unapodized SAW transducer; Bandwidth; Dispersion; Equations; Frequency response; Permittivity; Piezoelectric transducers; Surface acoustic wave devices; Surface acoustic waves; Tensile stress; Zinc oxide;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
