To solve the problem that conventionally the frequency band which can be used by a balanced transformer is not able to be adjusted once the balanced transformer is manufactured and the transformer must be redesigned, when the usable frequency band is changed according to the type mobile communication equipment, and then the balanced transformer must be disposed as a defective balanced transformer, when the line width constituting a coil fluctuates and desired characteristic is not obtained.
The balanced transformer is constituted, by alternately laminating insulating layers and conductor layers upon another and providing first and second coils which are connected between a terminal for unbalance and a dummy terminal and have the same number of turns and third and fourth coils, which are connected between paired terminals for unbalance and have the same number of turns in the laminated bodies of the insulating layers. The first and second coils are connected electromagnetically to the third and fourth coils, respectively. The junction between the third and fourth coils is grounded via a grounding terminal. The terminal for unbalance, dummy terminal, paired terminals for unbalance, and grounding terminal are formed on the side faces of the laminated body. At forming of the terminals, the size of the dummy terminal is made different from those of the other terminals.
SAKAKURA MITSUO
KOMIYAMA SHIGERU
