Design of Double Mode SAW Filters Using IDT/(100) ZnO/(111) Diamond Structure

Abstract

Propagation characteristics of surface acoustic waves (SAWs) in interdigital transducers (IDT)/(100) ZnO/diamond structures are investigated in this study using the finite element method. The effects of electrodes on phase velocity, coupling coefficient, and reflectivity of SAWs in the layered structures are illustrated. The extracted coupling-of-mode parameters are then applied to calculate frequency responses of double mode SAW filters using the transmission matrix method. Simulation results show a tailored filter applicable for wideband code division multiple access systems can be achieved.

Keywords:

• Surface acoustic wave
• finite element method
• coupling coefficient
• reflectivity
• filter

Acknowledgment

The authors would like to express their gratitude to the National Science Council of R.O.C. for their financial support of this research under contract no. NSC 98-2221-E-214-019 and no. NSC 98-2221-E-002-195.