High temperature stable super high electromechanical coupling SAW substrates and application for SAW devices

In this study, in order to improve the temperature coefficient of frequency (TCF), the propagation characteristics of SiO/sub 2//rotated Y-cut, X-propagating LiNbO/sub 3/ leaky surface acoustic wave (SAW) substrates with a large electromechanical coupling coefficient (k/sup 2/), zero attenuation and zero TCF are theoretically investigated. The results showed a large k/sup 2/ of more than 0.2 (zero k/sup 2/ of Rayleigh mode), zero TCF and zero propagation attenuation for leaky SAW in the case of a short boundary at a thin film thickness of H//spl lambda/=0.15/spl sim/0.22 (H=SiO/sub 2/ film thickness, /spl lambda/=SAW wavelength). The experimental results agreed with the theoretical ones.