Patent ID: 8203396

Claim:
A thin film balun comprising: an unbalanced transmission line having a first line portion and a second line portion; a balanced transmission line having a third line portion and a fourth line portion which are arranged so as to face the first line portion and the second line portion, respectively, the third line portion and the fourth line portion magnetically coupling with the first line portion and the second line portion, respectively; an unbalanced terminal connected to the first line portion; a ground terminal connected to the second line portion via a C component; a first balanced terminal connected to the third line portion; and a second balanced terminal connected to the fourth line portion, wherein: the first line portion has a first coil portion, the second line portion has a second coil portion, the third line portion has a third coil portion, the fourth line portion has a fourth coil portion, and the C component is provided in an area where the first coil portion and the third coil portion are overlapped or the second coil portion and the fourth coil portion are overlapped in a plan view.