Patent ID: 8648667

Claim:
A thin film balun comprising: an unbalanced transmission line including a first coil portion and a second coil portion, the first coil portion and the second coil portion each include a coil formed in a planar shape, and are arranged side-by-side such that the coils extend in the same plane; a balanced transmission line including a third coil portion and a fourth coil portion that are positioned facing the first coil portion and the second coil portion and magnetically coupled to the first coil portion and the second coil portion, respectively; an unbalanced terminal connected to the first coil portion; a ground terminal connected to the second coil portion via a C component; and an opposite electrode connected to the ground terminal and facing a part of the second coil portion, the part being inset from and not abutting an edge of the second coil portion in a cross-sectional view, and the part not forming any terminal portion of the second coil portion, wherein the C component is formed by the opposite electrode and the part of the second coil portion.