Patent ID: 8264122

Claim:
An acoustic wave device comprising: a piezoelectric substrate made of LiNbO 3 ; a dielectric layer laminated on the piezoelectric substrate; an IDT electrode disposed at an interface of the piezoelectric substrate and the dielectric layer, φ and θ of Euler angles expressed by (φ, θ, ψ) of LiNbO 3 substrate satisfying φ=about 0° and 80°≦θ≦130° respectively, the acoustic wave device using an acoustic wave primarily having an SH wave; wherein ψ is set to satisfy 5°≦ψ≦30°; the dielectric layer is SiO 2 ; the acoustic wave device is a surface acoustic wave device that utilizes an SH type surface acoustic wave as an acoustic wave; and θ of the Euler angles of LiNbO 3 is in the range of 80°≦θ≦90°.