Patent ID: 6791237
Filing Date: 2004-09-14
Classification: H03H

Abstract:
A surface acoustic wave substrate, comprising:a piezoelectric or electrostrictive substrate having large electromechanical coupling coefficient; and a thin SiO2, film formed on said substrate and having variation characteristics of frequency of a surface acoustic wave relative temperature variation opposite to that of said substrate, wherein said substrate is a LiNbO3 substrate having a cut angle of rotated Y plate within a range greater than or equal to âˆ’10Â° and smaller than or equal to +30Â° and propagating a piezoelectric leaky surface wave having a propagation velocity higher than that of a Rayleigh type surface acoustic wave along X-axis directon or within a range of Â±5Â° with respect to X-axis direction, and a value of H/&lgr; falls within a range from 0.05 to 0.35, where H is the film thickness of said thin SiO2 film, and &lgr; is the wavelength of operating center frequency of said piezoelectric leaky surface wave.