Surface acoustic wave resonator, surface acoustic wave filter, and multiplexer

A surface acoustic wave resonator comprising:

• a substrate including a piezoelectric layer;
• at least one first electrode on the substrate and including a first interdigital transducer (IDT) electrode;
• and
• a plurality of first load layers spaced apart from each other on the substrate or in the substrate and including a dielectric;
• wherein
• the at least one first electrode includes a plurality of first electrode fingers arranged along a first axis on the substrate and each extending along a second axis perpendicular or substantially perpendicular to the first axis;
• each of the plurality of first load layers at least partially overlaps at least one corresponding first electrode finger of the plurality of first electrode fingers in plan view of the substrate;
• a number of first electrode fingers overlapping the plurality of first load layers among the plurality of first electrode fingers in a first sub-region and a number of first electrode fingers overlapping the plurality of first load layers among the plurality of first electrode fingers in a third sub-region are each larger than a number of first electrode fingers overlapping the plurality of first load layers among the plurality of first electrode fingers in a second sub-region;
• the first sub-region, the second sub-region, and the third sub-region are obtained by equally dividing, in a direction of the first axis, a region in which the plurality of first electrode fingers are located on the substrate;
• the second sub-region is located between the first sub-region and the third sub-region;
• and
• the plurality of first load layers include two or more first load layers overlapping the first electrode fingers located in the first sub-region and two or more first load layers overlapping the first electrode fingers located in the third sub-region.