Analysis on saw device of LiNbO<inf>3</inf> film with multi-layered media

In this paper, the propagation of the surface acoustic wave (SAW) in LiNbO3 structure with multi-layered media is introduced. The SAW devices with LiNbO3 structure are simulated by finite element methods, symmetry and anti-symmetry resonance modes of vibration with the corresponding resonant frequency are obtained. The effects of interdigital transducer (IDT)parameters on the performance of the device are analyzed; the changes in resonance frequency of SAW device due to the electrical loading are studied for various metallization ratios and thickness of the interdigital transducer. According to the simulation results and technological conditions, the optimum parameters areselected for the design of the gas sensor. With the concentration - frequency coefficient is approximately 1.412 ppm/Hz, which has an excellent linear relationship.