MATCHING CIRCUIT, MATCHING CIRCUIT ELEMENT, AND COMMUNICATION DEVICE

摘要

A matching circuit includes first and second input/output ports; first, second, and third coils; and a capacitor. The first coil is connected in series between the first and second input/output ports, and the second coil is connected in shunt between a ground and an input/output line between the first and second input/output ports. The first and second coils are magnetically coupled to each other, the third coil is magnetically coupled to at least one of the first and second coils, the capacitor is directly or indirectly connected to the third coil, and a closed circuit including the capacitor and the third coil is provided.