Multiplexer, high frequency front-end circuit, and communication apparatus

A multiplexer comprising:

• a common terminal, a first input-output terminal, and a second input-output terminal;
• a first filter electrically connected to the common terminal and the first input-out terminal;
• and
• a second filter having a pass band different from a pass band of the first filter, and electrically connected to the common terminal and the second input-output terminal;
• wherein
• the first filter includes a plurality of series arm resonators provided on a path connecting the common terminal and the first input-output terminal, and a plurality of parallel arm resonators provided between the path and ground;
• each of the plurality of series arm resonators and the plurality of parallel arm resonators is an acoustic wave resonator including an interdigital transducer (IDT) electrode provided on a substrate having piezoelectricity;
• a capacitance element is electrically connected in parallel to at least one of a first series arm resonator, which is a series arm resonator connected most proximately to the common terminal among the plurality of series arm resonators, and a first parallel arm resonator, which is a parallel arm resonator connected most proximately to the common terminal among the plurality of parallel arm resonators, and the IDT electrode included in the at least one of the first series arm resonator and the first parallel arm resonator does not include a thinning electrode;
• and
• the IDT electrode included in at least one of the series arm resonators excluding the first series arm resonator among the plurality of series arm resonators and the parallel arm resonators excluding the first parallel arm resonator among the plurality of parallel arm resonators, includes a thinning electrode.