Patent ID: 6838807

Claim:
A surface acoustic wave device comprising: a piezoelectric substrate; an electrode unit for exciting a surface acoustic wave on a surface of said piezoelectric substrate; and reflectors for reflecting the surface acoustic wave at said reflectors, wherein: said electrode unit comprises interdigital electrodes including a thin-film layer formed of copper or a copper alloy, and a connecting electrode connected to each of the interdigital electrodes; and when a wavelength of the surface acoustic wave is indicated by λ, and when a thickness of the interdigital electrodes is indicated by H, a standardized thickness H/λ of the interdigital electrodes ranges from 0.045 to 0.070, and said piezoelectric substrate is a rotated Y-cut LiTaO 3 substrate whose cut angle θ from a Y axis to an Z axis around an X axis ranges from 52.0° to 58.0°, the surface acoustic wave propagating in a direction of the X axis of said piezoelectric substrate.