Hitachi Metals, Ltd.

Hitchi Metals, Ltd.

Shinichirou Takeuchi

Yasushi Kishimoto

Hideto Horiguchi

Shinji Yamamoto

Hiroyuki Itoh

Shigeru Takeda

Youichi Takahashi

Yukinori Arita

Manabu Yumoto

A high-frequency circuit for use in a multiband wireless apparatus for switching the connection between an antenna and transmission/reception circuits depending on signals for pluralities of communications systems, comprising a single-pole, multi-throw switch circuit comprising FET switch circuits between a common port connected to an antenna-side circuit and pluralities of single ports connected to the transmission/reception circuits, and a first matching circuit connected to the common port; the first matching circuit comprising a first inductance element connected in series to a signal path between the antenna and the common port, and a first capacitance element connected to the first inductance element on the antenna side and grounded; the first inductance element making the impedance of the single-pole, multi-throw switch circuit inductive when the single port is viewed from the antenna side; and the first capacitance element adjusting impedance matching between the antenna-side circuit and the transmission/reception circuits.

High-frequency circuit, high-frequency device, and multiband communications apparatus

A two-port isolator comprising a thin ferrite plate, a permanent magnet for applying a static magnetic field to the thin ferrite plate, first and second central conductors disposed substantially in a center portion of the thin ferrite plate and crossing each other with electric insulation, first and second input-output terminals each connected to an end of each of the first and second central conductors, a common terminal connected to the other ends of the first and second central conductors, a first matching capacitor connected between the first input-output terminal and the common terminal, a second matching capacitor connected between the second input-output terminal and the common terminal, and a resistor connected between the first input-output terminal and the second input-output terminal, wherein the DC resistance of the resistor is set, such that with loss in a high-frequency signal entering into the first input-output terminal and exiting from the second input-output terminal defined as insertion loss, and with loss in a high-frequency signal entering into the second input-output terminal and exiting from the first input-output terminal defined as isolation loss, the insertion loss is smaller than the isolation, and that the isolation loss increases as a static magnetic field applied to the two-terminal isolator from outside increases.

Two-port isolator and method for evaluating it

An irreversible circuit module includes a permanent magnet for providing a DC magnetic field for a magnetic member; an assembly having a magnetic member provided with a plurality of conductors being common on one end and serving as input and output terminals for high-frequency signals on the other end; a plurality of load capacitors connected to the conductors, the load capacitors being formed in a laminate having a conductor layer: a first transmission line connected to any of the conductors; and a second transmission line coupled magnetically to the first transmission line. The first transmission line and the second transmission line are included in the laminate. The assembly is received in a hole in the middle of the laminate.

Irreversible circuit module including a directional coupler

Growing community of inventors

Tottori-ken, Japan

Shinichirou Takeuchi