Surface acoustic wave devie suitable for use in GHz band

摘要

IDT electrodes (13) are formed by a Cu alloy. When the wavelength of a SAW propagating in the direction of the X axis of a piezoelectric substrate (12) is indicated by λ, and when the thickness of the IDT electrodes is indicated by H, the standardized thickness H/λ of the IDT electrodes ranges from 0.045 to 0.070, and the piezoelectric substrate is a rotated Y-cut LiTaO3 substrate whose rotational cut angle θ from the Y axis to the Z axis around the X axis ranges from 52.0° to 58.0°. With this arrangement, the reflection coefficient S11 becomes 0.88 or higher.