Patent ID: 7256663

Claim:
A balance filter device comprising: a filter unit formed by laminating a plurality of dielectric substrates; and a balun device comprising: a pair of ground (GND) electrodes formed on respective dielectric layers; an unbalanced resonance electrode formed on a dielectric layer; a balanced resonance electrode formed on a dielectric layer, the unbalanced resonance electrode and the balanced resonance electrode being disposed between the pair of ground (GND) electrodes by laminating the dielectric layers; and an intermediate electrode disposed between one of the unbalanced resonance electrode or the balanced electrode and the ground (GND) electrode near the one of the unbalanced resonance electrode or the balanced electrode wherein the intermediate electrode is formed larger than the ground (GND) electrode, the filter unit being connected to the unbalanced resonance electrode of the balun unit, wherein the filter unit and the balun unit are formed of the same dielectric material.