Murata Manufacturing Co., Ltd.

Akihito Masuda

Takashi Kawanami

Toshihiro Makino

Takekazu Okada

Yoshihiko Ashida

A method of manufacturing a nonreciprocal circuit device is performed such that matching capacitors are formed of single-board-type capacitors including capacitor electrodes formed so as to be opposed to each other on both main surfaces of a dielectric substrate with the substrate in between. An outer peripheral edge of a ground electrode (or another connected electrode), to which a capacitor electrode of the single-board-type capacitor is connected, is positioned inwardly from an outer peripheral edge of the capacitor electrode.

Method of manufacturing a nonreciprocal circuit device

A nonreciprocal circuit device is provided which prevents the center conductors thereof from interfering with each other when folded toward a magnetic body even when the magnetic body has a rectangle shape in plan view, and which thereby increases the reliability of the bonding portion between the center conductor coupling portion and capacitors or input/output terminals, and a communication device using the same is further provided. A ferrite having a rectangle shape in plan view is placed on the coupling portion of the center conductors, and a magnetic assembly is constructed by folding the center conductors extending from the coupling portion outward so as to wrap the ferrite. At this time, the port portions of the center conductors extending from the coupling portion outward substantially line-symmetrically are formed asymmetrically with each other so as not to mutually interfere when these center conductors are folded toward the magnetic body.

Nonreciprocal circuit device and communication apparatus

A nonreciprocal circuit device requires less layout space when single-board capacitors are used, and meets demands for a smaller and lighter configuration. An isolator (nonreciprocal circuit device) comprises a ferrite, a permanent magnet applying a direct current magnetic field to the ferrite, a plurality of central electrodes respectively having ports disposed on the ferrite and a single-based matching capacitor with capacitor electrodes formed on both surfaces of a dielectric substrate such that the capacitor electrodes are opposed to each other and sandwich the dielectric substrate. In various embodiments, the permanent magnet and/or; the ferrite has a square shape and the capacitor electrodes of the matching capacitors are arranged at an angle of 60 to 90 degrees with respect a mounting surface and the matching capacitors are disposed so as to surround the sides of the ferrite.

Nonreciprocal circuit device

In the disclosed nonreciprocal circuit device, which employs a single-board-type capacitor, the problem of electrode peeling can be avoided. The nonreciprocal circuit device has characteristics such that attenuation is small in the direction of signal transmission and attenuation is large in the reverse direction and has matching capacitors disposed in signal input/output ports. The matching capacitors are formed of single-board-type capacitors including capacitor electrodes formed so as to be opposed each other on both main surfaces of a dielectric substrate with the substrate in between. An outer peripheral edge of a grounding electrode (or another connected electrode), to which a capacitor electrode of the single-board-type capacitor is connected, is positioned inwardly from an outer peripheral edge of the capacitor electrode.

A nonreciprocal circuit device that avoids the problems of increased loss and narrowed frequency bandwidth when used with a low power supply voltage. An isolator (nonreciprocal circuit device) has a plurality of center electrodes (2 through 4) disposed so as to intersect and having a ferrite (5) disposed in alignment with the point of intersection, to which a DC magnetic field HDC is applied. An impedance conversion circuit (6) is added to the port of any one of center electrodes (2 through 4), setting the input impedance Zi to 2&lt;Zi&lt;12.5 ohms.

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Kanazawa, Japan

Akihito Masuda