Filter and multiplexer

A filter comprising:

• a filter circuit defining a first signal path connecting a first terminal and a second terminal;
• and
• an additional circuit that is connected to a first node located between the first terminal and the filter circuit on the first signal path and a second node located between the second terminal and the filter circuit on the first signal path;
• wherein
• the additional circuit defines a second signal path connecting the first node and the second node;
• the additional circuit includes, on the second signal path:
• a resonator group including a plurality of inter digital transducer (IDT) electrodes located adjacent to or in a vicinity of each other in an acoustic wave propagation direction;
• a capacitive element;
• a multilayer wiring board where a pattern conductor is provided;
• and
• a piezoelectric substrate which is provided on one main surface of the multilayer wiring board and at which the plurality of IDT electrodes and a wiring electrode are provided;
• the resonator group and the capacitive element are defined by the IDT electrode;
• the first inductance element is defined by the wiring electrode;
• the second inductance element is defined by the pattern conductor;
• and
• the first inductance element and the second inductance element are located in a region where the first inductance element and the second inductance element at least partly overlap each other when the multilayer wiring board and the piezoelectric substrate are viewed in plan.

A multiplexer, comprising:

• a multilayer wiring board;
• a piezoelectric substrate;
• a connection electrode that connects the multilayer wiring board to the piezoelectric substrate;
• a pattern conductor that is provided in the multilayer wiring board and that defines at least one first inductor;
• a plurality of inter digital transducer (IDT) electrodes provided on a surface of the piezoelectric substrate that faces the multilayer wiring board;
• a wiring electrode that is provided on the surface of the piezoelectric substrate that faces the multilayer wiring board and that defines at least one second inductor.