Acoustic wave device, radio-frequency front-end circuit, and communication apparatus

Abstract

An acoustic wave device includes an IDT electrode provided on a piezoelectric substrate. The IDT electrode includes a crossing area including a central area, and first and second low-acoustic-velocity areas on both sides in a direction perpendicular or substantially perpendicular to an acoustic wave propagating direction. First and second high-acoustic-velocity areas are provided outside the first and second low-acoustic-velocity areas. Mass adding films are laminated in respective portions of first and second electrode fingers, the respective portions being positioned in the first and second low-acoustic-velocity areas. In at least one of the mass adding films, a width of a first end portion and a width of a second end portion are narrower than a width of a central portion, and a protruding portion protrudes from at least one of the first and second end portions.