| 摘要 |
Disclosed is a surface acoustic wave substrate including: a piezoelectric or electrostrictive substrate having large electromechanical coupling coefficient; and a thin film formed on the substrate and having variation characteristics of frequency of a surface acoustic wave relative temperature variation opposite to that of the substrate. The substrate is a LiNbO3 substrate having a cut angle of rotated Y plate within a range from -10° to +30° and propagating a piezoelectric leaky surface wave having a propagation velocity higher than that of a Rayleigh type surface acoustic wave along X-axis direction or within a range of ±5° with respect to X-axis direction. A value of H/lambda falls within a range from 0.05 to 0.35, where H is the film thickness of the thin film, and lambda is the wavelength of operating center frequency of the piezoelectric leaky surface wave.
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