Patents by Inventor Kazuhiko Ishimoto
Kazuhiko Ishimoto has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11880218Abstract: A current output circuit includes an input circuit that outputs a second current in response to a first current when the first current is inputted, an output circuit that outputs a third current in response to the second current, and a control circuit that causes the output circuit to output a current when a control signal is inputted before the first current is inputted to the input circuit. The output circuit includes transistors of a first group and the input circuit includes transistors of a second group.Type: GrantFiled: May 25, 2021Date of Patent: January 23, 2024Assignee: MURATA MANUFACTURING CO., LTD.Inventor: Kazuhiko Ishimoto
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Publication number: 20230216454Abstract: A current control circuit controls a bias current that is supplied to an amplifier transistor that amplifies a radio-frequency signal and includes a node, a constant current source circuit that supplies a first current to the node, and a variable current source circuit that supplies a second current to the node, based on a result of comparison between a potential of the node and a reference potential. The node outputs a control current including the first current and the second current for controlling the bias current.Type: ApplicationFiled: March 13, 2023Publication date: July 6, 2023Inventor: Kazuhiko ISHIMOTO
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Patent number: 11489493Abstract: A current control circuit controls a base current of a first transistor included in a bias circuit outputting a bias current to a power amplifier based on a base-collector voltage of the first transistor. The current control circuit includes a first circuit that outputs a signal associated with the base-collector voltage of the first transistor, and a second circuit that, based on the signal, provides electrical continuity between a base of the first transistor and a reference potential.Type: GrantFiled: February 4, 2020Date of Patent: November 1, 2022Assignee: MURATA MANUFACTURING CO., LTD.Inventors: Mikiko Fukasawa, Kazuhiko Ishimoto
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Publication number: 20210278871Abstract: A current output circuit includes an input circuit that outputs a second current in response to a first current when the first current is inputted, an output circuit that outputs a third current in response to the second current, and a control circuit that causes the output circuit to output a current when a control signal is inputted before the first current is inputted to the input circuit. The output circuit includes transistors of a first group and the input circuit includes transistors of a second group.Type: ApplicationFiled: May 25, 2021Publication date: September 9, 2021Inventor: Kazuhiko ISHIMOTO
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Publication number: 20210234523Abstract: There is provided a power amplifier circuit with improved operation speed of the protection function against overcurrent or overvoltage. The power amplifier circuit includes an amplifier configured to amplify a radio frequency signal and output the radio frequency signal, a bias current supply circuit configured to supply a bias current to the amplifier, a detection circuit configured to detect whether the current or voltage of the amplifier is equal to or greater than a predetermined threshold; and a draw circuit configured to, when the detection circuit detects that the current or voltage is equal to or greater than the predetermined threshold, draw at least a part of the bias current supplied to the amplifier.Type: ApplicationFiled: April 14, 2021Publication date: July 29, 2021Inventors: Fuminori MORISAWA, Kazuhiko ISHIMOTO, Fumio HARIMA
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Publication number: 20200252029Abstract: A current control circuit controls a base current of a first transistor included in a bias circuit outputting a bias current to a power amplifier based on a base-collector voltage of the first transistor. The current control circuit includes a first circuit that outputs a signal associated with the base-collector voltage of the first transistor, and a second circuit that, based on the signal, provides electrical continuity between a base of the first transistor and a reference potential.Type: ApplicationFiled: February 4, 2020Publication date: August 6, 2020Inventors: Mikiko FUKASAWA, Kazuhiko ISHIMOTO
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Patent number: 9240760Abstract: A power amplifier module includes a first amplification transistor that amplifies and outputs a radio frequency signal, a second amplification transistor that is connected in parallel to the first amplification transistor and that has a smaller size than the first amplification transistor, a bias circuit that supplies a bias voltage or a bias current to the first and second amplification transistors, a current detector circuit that detects a current flowing in the second amplification transistor, and a bias control circuit that controls the bias voltage or the bias current supplied from the bias circuit to the first and second amplification transistors depending on the detection result of the current detector circuit.Type: GrantFiled: November 13, 2014Date of Patent: January 19, 2016Assignee: MURATA MANUFACTURING CO., LTD.Inventors: Kazuhiko Ishimoto, Takashi Soga
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Publication number: 20150070092Abstract: A power amplifier module includes a first amplification transistor that amplifies and outputs a radio frequency signal, a second amplification transistor that is connected in parallel to the first amplification transistor and that has a smaller size than the first amplification transistor, a bias circuit that supplies a bias voltage or a bias current to the first and second amplification transistors, a current detector circuit that detects a current flowing in the second amplification transistor, and a bias control circuit that controls the bias voltage or the bias current supplied from the bias circuit to the first and second amplification transistors depending on the detection result of the current detector circuit.Type: ApplicationFiled: November 13, 2014Publication date: March 12, 2015Inventors: Kazuhiko Ishimoto, Takashi Soga
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Patent number: 7332966Abstract: A high frequency power amplifier circuit includes amplifying devices whose control terminals (gate or base terminals) are supplied with a bias voltage. The high frequency power amplifier circuit keeps constant the bias voltage so that the amplifying devices operate in a saturation region. The high frequency power amplifier circuit controls an operating power supply voltage supplied to the amplifying devices in accordance with an output request level to control output power. A device (diode) having temperature dependency is provided for an operating power supply voltage control circuit that controls the operating power supply voltage for the amplifying devices in accordance with the output request level. The operating power supply voltage control circuit is configured to generate the operating power supply voltage corresponding to the device's temperature characteristics and supply it to the amplifying devices.Type: GrantFiled: March 9, 2006Date of Patent: February 19, 2008Assignee: Renesas Technology Corp.Inventors: Tomio Furuya, Kazuhiko Ishimoto, Hiroyuki Tanaka
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Patent number: 7271658Abstract: An RF power module in which operating voltage is controlled by a control signal based on amplitude information includes a temperature detecting device which is provided over a semiconductor chip formed with an amplifying transistor or a semiconductor chip formed with a power source circuit; and a detector having a hysteresis characteristic which is provided over the semiconductor chip formed with the device or a different semiconductor chip, applies a bias to the temperature detecting device to compare the state of the device at two reference levels, outputs a signal indicating abnormality when judging that the temperature of the semiconductor chip formed with the temperature detecting device is above a predetermined temperature, and outputs a signal indicating normality when judging that the temperature of the semiconductor chip is below a second predetermined temperature lower than the predetermined temperature.Type: GrantFiled: June 10, 2005Date of Patent: September 18, 2007Assignees: Renesas Technology Corp., Hitachi Hybrid Network, Co., Ltd.Inventors: Kouichi Matsushita, Kenichi Shimamoto, Kazuhiro Koshio, Kazuhiko Ishimoto, Takayuki Tsutsui
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Publication number: 20060214729Abstract: A high frequency power amplifier circuit includes amplifying devices whose control terminals (gate or base terminals) are supplied with a bias voltage. The high frequency power amplifier circuit keeps constant the bias voltage so that the amplifying devices operate in a saturation region. The high frequency power amplifier circuit controls an operating power supply voltage supplied to the amplifying devices in accordance with an output request level to control output power. A device (diode) having temperature dependency is provided for an operating power supply voltage control circuit that controls the operating power supply voltage for the amplifying devices in accordance with the output request level. The operating power supply voltage control circuit is configured to generate the operating power supply voltage corresponding to the device's temperature characteristics and supply it to the amplifying devices.Type: ApplicationFiled: March 9, 2006Publication date: September 28, 2006Inventors: Tomio Furuya, Kazuhiko Ishimoto, Hiroyuki Tanaka
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Publication number: 20050280471Abstract: An RF power module in which operating voltage is controlled by a control signal based on amplitude information includes a temperature detecting device which is provided over a semiconductor chip formed with an amplifying transistor or a semiconductor chip formed with a power source circuit; and a detector having a hysteresis characteristic which is provided over the semiconductor chip formed with the device or a different semiconductor chip, applies a bias to the temperature detecting device to compare the state of the device at two reference levels, outputs a signal indicating abnormality when judging that the temperature of the semiconductor chip formed with the temperature detecting device is above a predetermined temperature, and outputs a signal indicating normality when judging that the temperature of the semiconductor chip is below a second predetermined temperature lower than the predetermined temperature.Type: ApplicationFiled: June 10, 2005Publication date: December 22, 2005Inventors: Kouichi Matsushita, Kenichi Shimamoto, Kazuhiro Koshio, Kazuhiko Ishimoto, Takayuki Tsutsui