COMMON MODE FILTER

PROBLEM TO BE SOLVED: To provide a highly integrated common mode filter capable of obtaining a filter characteristic for practical use.SOLUTION: The common mode filter for use in a transmission circuit, which propagates differential signals on a first transmission line and a second transmission line to transmit a signal, includes a pair of inductors 11, 21 and a plurality of capacitors. The inductors are formed in an arrangement of being mutually magnetically coupled. The common mode filter includes: a first layer having a formed conductor pattern to be the capacitor; a third layer having a formed conductor pattern to be the capacitor and the inductor; and a second layer composed of a dielectric material sandwiched by the first layer and the third layer in the thickness direction. The capacitor is constituted by the conductor patterns disposed to face each other across the second layer.SELECTED DRAWING: Figure 10 【課題】実用可能なフィルタ特性と高集積化が可能なコモンモードフィルタを提供する。【解決手段】第１の伝送線路と第２の伝送線路に差動信号を伝播させて信号を伝送する伝送回路に用い、一対のインダクタ１１、２１と複数のキャパシタとから構成され、インダクタが相互に磁気的に結合される配置として形成される。キャパシタとなる導体パターンを形成した第１層と、キャパシタとなる導体パターン及びインダクタとを形成した第３層と、第１層と第３層とにより厚さ方向に挟まれた、誘電体材からなる第２層とから形成され、キャパシタは、第２層を挟んで対向配置されている導体パターンによって構成される。【選択図】図１０