To provide a balun mounted device capable of matching the impedance of a transmission line balun.
A balun mounted device includes a layered balun configured by opposing two balanced signal transmission lines 30, 35 and an unbalanced signal transmission line 50 via a dielectric layer 24. One ends of the balanced signal transmission lines 30, 35 are a balanced signal output/input terminal 30a, 35a, respectively, and the other ends thereof are a ground terminal 30b, 35b, respectively. The balanced signal transmission lines 30, 35 are provided independently electrically. One end of the unbalanced signal transmission line 50 is an unbalanced signal input/output terminal 50a; and the other end thereof is an open terminal 50b. In the balun mounted device, an inductor 120 is connected in series with the unbalanced signal transmission line 50. One end of the inductor 120 is conducted to the unbalanced signal input/output terminal 50a; and the other end is conducted to an unbalanced signal input/output terminal part 59 for inputting/outputting an unbalanced signal to/from the layered balun. The inductor 120 is disposed in a central space part E2 of a plane spiral part 50d at a side of the unbalanced signal transmission part 50, having the unbalanced signal input/output terminal 50a.
AIZAWA TAKUYA
NAKAO SATORU
Tadashi Takahashi
Takashi Watanabe