Composite filter device

A composite filter device comprising:

• a piezoelectric substrate;
• a first filter that is a band pass filter and that includes a longitudinally coupled resonator acoustic wave filter provided on the piezoelectric substrate;
• a second filter that includes at least one resonator and an inductor connected to a reference potential;
• and
• a reference potential wiring line that is a wiring line provided on the piezoelectric substrate and connected to the reference potential, that has a substantially annular portion having an annular shape including a gap, and that surrounds, in the substantially annular portion, the longitudinally coupled resonator acoustic wave filter;
• wherein
• the substantially annular portion of the reference potential wiring line includes a first end portion and a second end portion that face each other across the gap, and a reference potential connection portion that extends with the first end portion as a starting point and that connects the longitudinally coupled resonator acoustic wave filter to the reference potential;
• the inductor includes one parallel wiring portion that extends in parallel or substantially in parallel with the reference potential connection portion in plan view, or two or more parallel wiring portions that extend in parallel or substantially in parallel with the reference potential connection portion and are arranged in a direction perpendicular to a direction in which the reference potential connection portion extends in plan view such that currents flowing through the two or more parallel wiring portions have a same direction;
• and
• when a region including an area from a parallel wiring portion positioned on a side closest to one side in a direction perpendicular to a direction in which the parallel wiring portion extends to a parallel wiring portion positioned on a side closest to another side in the direction perpendicular to the direction in which the parallel wiring portion extends is defined as a parallel wiring portion region, the parallel wiring portion region and the reference potential connection portion overlap with each other in plan view, and a direction of a current flowing through the parallel wiring portion and a direction of a current flowing through the reference potential connection portion are same.