Abstract: An amplifier circuit includes: a transistor provided between an input terminal and an output terminal and having a gate connected to the input terminal, a source connected to a ground, and a drain connected to the output terminal; an inductor connected between the source and the ground; an inductor connected between the gate and the input terminal, and switches connected to at least one of the inductors and configured to change a mutual inductance of the inductors.

Abstract: A magnetic sensor senses a magnetic field in a predetermined magnetic sensing direction. The magnetic sensor includes a chip on which at least one magnetic device is provided. The length of the chip in the magnetic sensing direction is twice or more the length of the chip in an orthogonal direction that is orthogonal or substantially orthogonal to the magnetic sensing direction.

Abstract: An amplifier circuit includes: a transistor provided between an input terminal and an output terminal and having a gate connected to the input terminal, a source connected to a ground, and a drain connected to the output terminal; an inductor connected between the source and the ground; an inductor connected between the gate and the input terminal, and switches connected to at least one of the inductors and configured to change a mutual inductance of the inductors.

Abstract: A current sensor includes a substrate including a through-hole and at least one groove around the through-hole, a primary conductor extending into the through-hole and through the substrate, and through which a current to be measured flows, at least one magnetic sensor that is mounted on a first surface of the substrate and detects a strength of a magnetic field generated by the current to be measured flowing through the primary conductor, and at least one magnetic body surrounding the primary conductor and including a portion extending in the at least one groove to be fixed to the substrate.

Abstract: A magnetic sensor senses a magnetic field in a predetermined magnetic sensing direction. The magnetic sensor includes a chip on which at least one magnetic device is provided. The length of the chip in the magnetic sensing direction is twice or more the length of the chip in an orthogonal direction that is orthogonal or substantially orthogonal to the magnetic sensing direction.

Abstract: A conductor includes a first flow path portion and a second flow path portion through which a current as a measurement target flows in a branched manner at a halfway position in a lengthwise direction of the conductor. The first flow path portion and the second flow path portion are located with a space therebetween in the width direction of the conductor when viewed from the thickness direction of the conductor. A region surrounded by the first flow path portion and the second flow path portion is provided when viewed from the width direction of the conductor. At least a portion of a substrate is located in the region and opposes at least one of the first flow path portion and the second flow path portion when viewed from the width direction of the conductor. The first magnetic sensor and the second magnetic sensor are arranged in the space.

Abstract: A current sensor includes a primary conductor in which a current flows, a magnetic sensor that detects a strength of a magnetic field produced by the current, and a magnetic body that surrounds a periphery of the primary conductor and the magnetic sensor. Output characteristics of the magnetic sensor include a low-output region in which a measured voltage value lower than a virtual output voltage proportional to a value of the current is outputted. Magnetization characteristics of the magnetic body include a magnetic saturation region in which permeability decreases in ranges where an absolute value of the current is no less than a threshold. An output of the magnetic sensor is corrected such that the measured voltage value increases as a result of a magnetic field leaking from the magnetic body that is within the magnetic saturation region acting on the magnetic sensor that is in the low-output region.

Abstract: A conductor includes a first flow path portion and a second flow path portion through which a current as a measurement target flows in a branched manner at a halfway position in a lengthwise direction of the conductor. The first flow path portion and the second flow path portion are located with a space therebetween in the width direction of the conductor when viewed from the thickness direction of the conductor. A region surrounded by the first flow path portion and the second flow path portion is provided when viewed from the width direction of the conductor. At least a portion of a substrate is located in the region and opposes at least one of the first flow path portion and the second flow path portion when viewed from the width direction of the conductor. The first magnetic sensor and the second magnetic sensor are arranged in the space.

Abstract: An electric current sensor includes a primary conductor through which an electric current to be measured flows, and at least one magnetic sensor. The magnetic sensor includes a first magnetic sensor area, the output sensitivity of which is decreased when a magnetic field is applied to include a magnetic field component in a first direction along a sensitivity variation axis, and a second magnetic sensor area, the output sensitivity of which is increased when the magnetic field is applied to include a magnetic field component in a second direction that is opposite to the first direction.

Abstract: An electric current sensor includes a primary conductor through which an electric current to be measured flows, and at least one magnetic sensor. The magnetic sensor includes a first magnetic sensor area, the output sensitivity of which is decreased when a magnetic field is applied to include a magnetic field component in a first direction along a sensitivity variation axis, and a second magnetic sensor area, the output sensitivity of which is increased when the magnetic field is applied to include a magnetic field component in a second direction that is opposite to the first direction.

Abstract: A current sensor includes a substrate including a through-hole and at least one groove around the through-hole, a primary conductor extending into the through-hole and through the substrate, and through which a current to be measured flows, at least one magnetic sensor that is mounted on a first surface of the substrate and detects a strength of a magnetic field generated by the current to be measured flowing through the primary conductor, and at least one magnetic body surrounding the primary conductor and including a portion extending in the at least one groove to be fixed to the substrate.

Abstract: A current sensor includes a primary conductor in which a current to be measured flows, at least one magnetic sensor that detects a strength of a magnetic field produced by the current flowing in the primary conductor, and a magnetic body that surrounds a periphery of the primary conductor and the magnetic sensor. Output characteristics of the magnetic sensor include a low-output region in which a measured voltage value lower than a virtual output voltage proportional to a value of the current is outputted. Magnetization characteristics of the magnetic body include a magnetic saturation region in which permeability decreases in ranges where an absolute value of the current is no less than a threshold. An output of the magnetic sensor is corrected such that the measured voltage value increases as a result of a magnetic field leaking from the magnetic body that is within the magnetic saturation region acting on the magnetic sensor that is in the low-output region.

Abstract: A busbar module including a busbar through which current of a measurement subject flows and a hold portion that holds the busbar and has a recess portion), the busbar and the hold portion being integrally formed; and a magnetic sensor module including a magnetic sensor that detects an intensity of a magnetic field generated by the current flowing through the busbar, and being able to be selectively assembled with the busbar module by housing the magnetic sensor module to the recess portion of the hold portion are included.

Abstract: A busbar module including a busbar through which current of a measurement subject flows and a hold portion that holds the busbar and has a recess portion), the busbar and the hold portion being integrally formed; and a magnetic sensor module including a magnetic sensor that detects an intensity of a magnetic field generated by the current flowing through the busbar, and being able to be selectively assembled with the busbar module by housing the magnetic sensor module to the recess portion of the hold portion are included.

Abstract: A non-reciprocal circuit device includes a ferrite arranged to receive a direct-current magnetic field from a permanent magnet, a first central electrode and a second central electrode arranged on the ferrite. The non-reciprocal circuit device further includes matching capacitors and a terminating resistor. When high frequency signals flow in a reverse direction, power consumption at the first central electrode is increased by decreasing an equivalent parallel resistance Rp of the first central electrode, in relation to power consumption at the terminating resistor.

Abstract: A nonreciprocal circuit device attenuates unnecessary waves having a higher frequency than that of a fundamental wave, without increasing insertion loss. The nonreciprocal circuit device in the form of a 2-port type isolator includes a ferrite on which a first central electrode and a second central electrode are arranged to cross each other and so as to be electrically insulated from each other. A bypass circuit including a phase shifter and a filter is provided between an input port and an output port, and the bypass circuit does not allow signals in the fundamental wave band to pass through and also attenuates harmonics.

Abstract: A non-reciprocal circuit element (for example, a 2-port isolator) includes a tabular yoke, permanent magnets, a ferrite to which a direct current magnetic field is applied from the permanent magnets, a first center electrode and a second center electrode disposed on the ferrite, and a circuit board. The tabular yoke is disposed on the upper surface of a ferrite magnet assembly with a dielectric layer therebetween. For example, the dielectric layer could be an adhesive agent layer made of an epoxy-based resin. The above arrangement provides a non-reciprocal circuit element having a simplified structure, a stable electrical characteristic, and a high reliability is provided.

Abstract: A nonreciprocal circuit device attenuates unnecessary waves having a higher frequency than that of a fundamental wave, without increasing insertion loss. The nonreciprocal circuit device in the form of a 2-port type isolator includes a ferrite on which a first central electrode and a second central electrode are arranged to cross each other and so as to be electrically insulated from each other. A bypass circuit including a phase shifter and a filter is provided between an input port and an output port, and the bypass circuit does not allow signals in the fundamental wave band to pass through and also attenuates harmonics.

Abstract: A non-reciprocal circuit device includes a ferrite arranged to receive a direct-current magnetic field from a permanent magnet, a first central electrode and a second central electrode arranged on the ferrite. The non-reciprocal circuit device further includes matching capacitors and a terminating resistor. When high frequency signals flow in a reverse direction, power consumption at the first central electrode is increased by decreasing an equivalent parallel resistance Rp of the first central electrode, in relation to power consumption at the terminating resistor.

Abstract: A nonreciprocal circuit device includes a permanent magnet, a ferrite to which the permanent magnet applies a direct-current magnetic field, first and second central electrodes arranged on the ferrite, and a circuit board. The first central electrode includes electrode layers provided on main surfaces of the ferrite connected by an electrode provided on a top surface of the ferrite. A second central electrode includes electrode layers provided on the main surfaces of the ferrite connected by electrodes arranged on top and bottom surfaces of the ferrite. The second electrode is wound at least about three turns around the ferrite. A width dimension of the outermost electrode layers of the second central electrode is greater than a width dimension of the inner electrode layers of the second central electrode.