Acoustic wave device

An acoustic wave device comprising:

• a piezoelectric substrate;
• and
• an IDT electrode on the piezoelectric substrate;
• wherein
• the IDT substrate includes a first busbar and a second busbar facing each other, a plurality of first electrode fingers extending toward the second busbar from the first busbar, and a plurality of second electrode fingers extending toward the first busbar from the second busbar;
• an intersection region in which the first electrode fingers and the second electrode fingers overlap each other in an acoustic wave propagation direction includes a central region at a center in an extending direction of the first electrode fingers and the second electrode fingers, and a first low acoustic velocity region and a second low acoustic velocity region outside the central region on respective sides in the extending direction of the first electrode fingers and the second electrode fingers;
• acoustic velocities in the first low acoustic velocity region and the second low acoustic velocity region are lower than an acoustic velocity in the central region;
• the first busbar and the second busbar each include a plurality of cavities arranged in the acoustic wave propagation direction;
• a portion on an intersection region side of the plurality of cavities in the first busbar and a portion on an intersection region side of the plurality of cavities in the second busbar are a first inner busbar portion and a second inner busbar portion, respectively;
• a portion on a side opposite to the intersection region of the plurality of cavities in the first busbar and a portion on a side opposite to the intersection region of the plurality of cavities in the second busbar are a first outer busbar portion and a second outer busbar portion, respectively;
• the first inner busbar portion and the second inner busbar portion are connected to the first outer busbar portion and the second outer busbar portion by a plurality of connecting portions;
• and
• at least one of the plurality of connecting portions is a wide width connecting portion with a dimension in the acoustic wave propagation direction larger than a dimension of each of remaining ones of the plurality of connecting portions.