Patent ID: 9425766
Filing Date: 2016-08-23
CPC Classification: H03H

Claim Text:
1. An acoustic wave device comprising: a piezoelectric substrate made of a lithium niobate material having Euler angles (φ, θ, ψ), the Euler angles satisfying conditions of −20°≦φ≦20°, −100°≦θ≦−60°, 1.193φ−2°≦ψ≦1.193φ+2°, and either ψ≦−2φ−3° or −2φ+3°≦ψ, the conditions simultaneously suppressing spurious transmissions derived from a Rayleigh wave and from a fast transverse wave excited in the piezoelectric substrate, the fast transverse wave being a fastest wave of transverse waves produced in the acoustic wave device; an inter-digital transducer (IDT) electrode disposed on the piezoelectric substrate and configured to excite a major acoustic wave of a wavelength λ; and a protective layer disposed on the piezoelectric substrate and covering the IDT electrode, the protective layer having a thickness greater than 0.27λ.