| 摘要 |
An elastic wave device includes a piezoelectric substrate, an IDT electrode disposed on a piezoelectric device, a first dielectric layer disposed on the piezoelectric substrate such that it covers the IDT electrode, and a second dielectric layer disposed over the first dielectric layer. The second dielectric layer propagates transverse waves faster than that on the first dielectric layer. When a film thickness of the second dielectric layer is greater than a wave length of a major wave excited by the IDT electrode, a cut angle of the piezoelectric substrate in indication of Euler angles (φ,θ,Φ) is set toφ≠0°,θ≠0°, andΦ≠0°. This suppresses deterioration of device characteristics.
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