Multiplexer

A multiplexer comprising:

• a common terminal, a first terminal, and a second terminal;
• a first filter in a first path connecting the common terminal and the first terminal, a pass band of the first filter being a first frequency band;
• and
• a second filter in a second path connecting the common terminal and the second terminal, a pass band of the second filter being a second frequency band, the second frequency band being in a lower frequency range below the first frequency band;
• wherein
• the first filter includes a longitudinally coupled acoustic wave resonator including an interdigital transducer electrode group including a plurality of interdigital transducer electrodes along an acoustic wave propagation direction;
• the interdigital transducer electrode group has an asymmetric shape with respect to a center line that passes through a center of the interdigital transducer electrode group and is perpendicular or substantially perpendicular to the acoustic wave propagation direction;
• and
• of the plurality of interdigital transducer electrodes, an aggregate average of electrode finger pitches of the interdigital transducer electrodes connected to the first path on a common terminal side when seen from the longitudinally coupled acoustic wave resonator is smaller than an aggregate average of electrode finger pitches of the interdigital transducer electrodes connected to the first path on a first terminal side, and a sum of numbers of pairs of electrode fingers of the interdigital transducer electrodes connected to the first path on the common terminal side is less than a sum of numbers of pairs of electrode fingers of the interdigital transducer electrodes connected to the first path on the first terminal side.