Acoustic wave device, acoustic wave filter, and multiplexer

An acoustic wave device comprising:

• a piezoelectric substrate;
• an interdigital transducer electrode on the piezoelectric substrate;
• and
• a reflector electrode on the piezoelectric substrate and adjacent to the interdigital transducer electrode in a first direction;
• wherein
• the interdigital transducer electrode includes a plurality of comb electrode fingers extending in a second direction intersecting the first direction;
• the reflector electrode includes a plurality of reflector electrode fingers extending in the second direction;
• among the plurality of comb electrode fingers, a comb electrode finger closest to the reflector electrode is defined as a first end-side electrode finger, and the comb electrode fingers arranged in a direction from the first end-side electrode finger toward a center of the interdigital transducer electrode are sequentially defined as nth end-side electrode fingers, where n is a natural number;
• among electrode fingers of the plurality of comb electrode fingers and the plurality of reflector electrode fingers, a center-to-center distance in the first direction between the electrode fingers adjacent to each other in the first direction is defined as a pitch, and a pitch between an nth end-side electrode finger and an (n+1)th end-side electrode finger is defined as an nth end-side pitch;
• among pitches arranged from the first end-side electrode finger to a comb electrode finger located in the center of the interdigital transducer electrode, an mth end-side pitch is smaller than an average of pitches of the plurality of comb electrode fingers except for the mth end-side pitch;
• and
• in a region where the interdigital transducer electrode is provided, when a region from the first end-side electrode finger to the mth end-side electrode finger is defined as an end region, the interdigital transducer electrode includes a thinned electrode in the end region.