Alps Electric Co., Ltd.

Hiroyuki Ishiwata

Akiyuki Yoshisato

Takashi Tanemura

Masami Miyazaki

A diplexer contains a common terminal connected to an antenna, a first input/output terminal for inputting/outputting signals of a plurality of high frequency bands higher than a predetermined frequency, and a second input/output terminal for inputting/outputting signals of low frequency bands lower than the predetermined frequency. Between the common terminal and the first input/output terminal, a high pass filter and low trap circuits for attenuating the low frequency bands respectively are interposed in series, and, between the common terminal and the second input/output terminal, a low pass filter and high trap circuits for attenuating the high frequency bands respectively are interposed in series.

Diplexer

A plurality of conductive patterns constituting first, second, and third inductors are formed in a multi-layer wiring board. A fifth dielectric layer is disposed between second to fourth dielectric layers having the first inductor and a seventh dielectric layer having the second inductor. First and second electrode layers are disposed facing each other across the fifth dielectric layer so as to constitute a capacitor. The capacitor is disposed between the first and third inductors and the second inductor. The first electrode layer, i.e., one electrode of the capacitor, is a ground layer.

Growing community of inventors

Fukushima-ken, Japan

Hiroyuki Ishiwata