There are provided: a first capacitor connected between first and second input/output terminals; a second capacitor connected between the first input/output terminal and a third input/output terminal; a first inductor having one end connected to the first input/output terminal; a second inductor having one end connected to the second input/output terminal and another end connected to another end of the first inductor; a third inductor having one end connected to the first input/output terminal; a fourth inductor having one end connected to the third input/output terminal and another end connected to another end of the third inductor; a first transistor having a drain terminal connected to said another ends of the first and second inductors and a source terminal that is grounded; and a second transistor having a drain terminal connected to said another ends of the third and fourth inductors and a source terminal that is grounded.