Impedance converting circuit and amplifier module

An impedance converting circuit comprising:

• a first primary line that has a first node at one end and a third node at an opposite end, and that is configured to transmit a first radio-frequency signal between the first node and the third node;
• a second primary line that has a second node at one end and a fourth node at an opposite end, and that is configured to transmit a second radio-frequency signal between the second node and the fourth node;
• a first secondary line that is connected to the second node and that is electromagnetically coupled to the first primary line;
• a second secondary line that has an end portion connected to the first node, that has an opposite end portion connected to an end portion of the first secondary line not connected to the second node, and that is electromagnetically coupled to the second primary line;
• and
• a first capacitor connected in parallel to a part of the second primary line or a part of the second secondary line.