Patents by Inventor Nobuhiro Matsudaira
Nobuhiro Matsudaira 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: 6885246Abstract: The present invention provides a high frequency amplifier using a power supply voltage regulate circuit for the purpose of compensating for variations in power supply voltage. The high frequency amplifier comprises three-stage power amplifiers which amplify an input signal and output the amplified signal, a bias circuit which supplies bias voltages for controlling these power amplifiers, a regulate circuit which compensates for variations in noise or gain with respect to the variations in the power supply voltage for driving the power amplifiers, etc. The regulate circuit holds constant an output voltage Vddc with respect to variations in power supply voltage Vdd and outputs the constant-held output voltage Vddc as a power supply voltage for the power amplifiers.Type: GrantFiled: February 21, 2003Date of Patent: April 26, 2005Assignee: Renesas Technology Corp.Inventors: Takayuki Tsutsui, Hiroyuki Nagamori, Kouichi Matsushita, Nobuhiro Matsudaira
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Publication number: 20040212436Abstract: A multistage high frequency power amplifier-circuit device has a plurality of semiconductor amplification elements connected in a cascade. The circuit device is provided with a bias control circuit used to control the bias voltage or bias current of the output semiconductor amplification element in each stage so as to reduce the variation of the output power with respect to the power control signal voltage in an area around the threshold voltage of the semiconductor amplification elements. This realizes a high frequency power amplifier circuit device provided with excellent controllability of the output power and high efficiency at the time of low power output realized with use of such a control voltage as a power control signal.Type: ApplicationFiled: May 21, 2004Publication date: October 28, 2004Applicants: Renesas Technology Corp., Hitachi Communications Systems, Inc.Inventors: Yoshikuni Matsunaga, Toshihiko Shimizu, Tomio Furuya, Nobuhiro Matsudaira, Koichi Matsushita
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Publication number: 20040212435Abstract: The present invention provides a high frequency power amplifier of an open-loop type, which outputs a signal having a level corresponding to an output level required under control of a power supply voltage for each output power FET, based on a control signal for the output level. The high frequency power amplifier is provided with a bias voltage generating circuit which generates a gate bias voltage of each output power FET according to an output voltage of a power control circuit for controlling the power supply voltage for the output power FET, based on the control signal for the output level.Type: ApplicationFiled: May 19, 2004Publication date: October 28, 2004Applicant: Renesas Technology Corp.Inventors: Satoshi Arai, Tsuyoshi Shibuya, Hitoshi Sekiguchi, Nobuhiro Matsudaira, Tomio Furuya, Masashi Maruyama, Yasushi Ohyama
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Publication number: 20040164808Abstract: A module including a bias circuit that generates gate bias voltages by resistance dividers creates a problem in that the values of the resistances constituting the bias circuit must be finely adjusted, and accordingly extra trimming tasks are required. The present invention provides current generators that generate currents varying with desired characteristics responsive to a control voltage, independent of variations in transistor threshold voltages, connects output resistors to parallel transistors in respective stages to form current mirror circuits, and supplies currents from the current generators thereto to drive them, instead of supplying dividing voltages.Type: ApplicationFiled: February 25, 2004Publication date: August 26, 2004Applicants: RENESAS TECHNOLOGY CORP., HITACHI COMMUNICATION SYSTEMS, INC.Inventors: Kouichi Matsushita, Tomio Furuya, Fuminori Morisawa, Takayuki Tsutsui, Nobuhiro Matsudaira
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Patent number: 6759906Abstract: A multistage high frequency power amplifier circuit device has a plurality of semiconductor amplification elements connected in a cascade. The circuit device is provided with a bias control circuit used to control the bias voltage or bias current of the output semiconductor amplification element in each stage so as to reduce the variation of the output power with respect to the power control signal voltage in an area around the threshold voltage of the semiconductor amplification elements. This realizes a high frequency power amplifier circuit device provided with excellent controllability of the output power and high efficiency at the time of low power output realized with use of such a control voltage as a power control signal.Type: GrantFiled: June 14, 2002Date of Patent: July 6, 2004Assignees: Renesas Technology Corp., Hitachi Communication Systems, Inc.Inventors: Yoshikuni Matsunaga, Toshihiko Shimizu, Tomio Furuya, Nobuhiro Matsudaira, Koichi Matsushita
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Patent number: 6756850Abstract: A module including a bias circuit that generates gate bias voltages by resistance dividers creates a problem in that the values of the resistances constituting the bias circuit must be finely adjusted, and accordingly extra trimming tasks are required. The present invention provides current generators that generate currents varying with desired characteristics responsive to a control voltage, independent of variations in transistor threshold voltages, connects output resistors to parallel transistors in respective stages to form current mirror circuits, and supplies currents from the current generators thereto to drive them, instead of supplying dividing voltages.Type: GrantFiled: May 17, 2002Date of Patent: June 29, 2004Assignees: Renesas Technology Corp., Hitachi Communication Systems, Inc.Inventors: Kouichi Matsushita, Tomio Furuya, Fuminori Morisawa, Takayuki Tsutsui, Nobuhiro Matsudaira
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Patent number: 6753735Abstract: The present invention provides a high frequency power amplifier of an open-loop type, which outputs a signal having a level corresponding to an output level required under control of a power supply voltage for each output power FET, based on a control signal for the output level. The high frequency power amplifier is provided with a bias voltage generating circuit which generates a gate bias voltage of each output power FET according to an output voltage of a power control circuit for controlling the power supply voltage for the output power FET, based on the control signal for the output level.Type: GrantFiled: November 15, 2002Date of Patent: June 22, 2004Assignee: Renesas Technology Corp.Inventors: Satoshi Arai, Tsuyoshi Shibuya, Hitoshi Sekiguchi, Nobuhiro Matsudaira, Tomio Furuya, Masashi Maruyama, Yasushi Ohyama
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Patent number: 6741125Abstract: The present invention provides a high frequency power amplifier of an open-loop type, which outputs a signal having a level corresponding to an output level required under control of a power supply voltage for each output power FET, based on a control signal for the output level. The high frequency power amplifier is provided with a bias voltage generating circuit which generates a gate bias voltage of each output power FET according to an output voltage of a power control circuit for controlling the power supply voltage for the output power FET, based on the control signal for the output level.Type: GrantFiled: January 8, 2003Date of Patent: May 25, 2004Assignee: Hitachi, Ltd.Inventors: Satoshi Arai, Tsuyoshi Shibuya, Hitoshi Sekiguchi, Nobuhiro Matsudaira, Tomio Furuya, Masashi Maruyama, Yasushi Ohyama
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Publication number: 20040075501Abstract: The present invention provides a high frequency amplifier suitable for use in a wireless communication system which performs detection of an output level necessary for feedback control by a current detection system, wherein control sensitivity in an area low in transmit request level is lowered so that an output level can be controlled over the whole control range with satisfactory accuracy. There is provided a high frequency power amplification electric part constituting a wireless communication system, which performs detection of an output level necessary for feedback control of output power by a current detection system, compares the output level detected signal and an output level designation signal and generates a bias voltage for a high frequency power amplifier according to the difference therebetween to thereby control gain, wherein an nth root converter or a logarithm converter is provided between a current detector and a current-voltage converter.Type: ApplicationFiled: October 10, 2003Publication date: April 22, 2004Inventors: Kyoichi Takahashi, Nobuhiro Matsudaira, Hitoshi Akamine
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Publication number: 20030184382Abstract: The present invention provides a high frequency amplifier using a power supply voltage regulate circuit for the purpose of compensating for variations in power supply voltage. The high frequency amplifier comprises three-stage power amplifiers which amplify an input signal and output the amplified signal, a bias circuit which supplies bias voltages for controlling these power amplifiers, a regulate circuit which compensates for variations in noise or gain with respect to the variations in the power supply voltage for driving the power amplifiers, etc. The regulate circuit holds constant an output voltage Vddc with respect to variations in power supply voltage Vdd and outputs the constant-held output voltage Vddc as a power supply voltage for the power amplifiers.Type: ApplicationFiled: February 21, 2003Publication date: October 2, 2003Inventors: Takayuki Tsutsui, Hiroyuki Nagamori, Kouichi Matsushita, Nobuhiro Matsudaira
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Patent number: 6605999Abstract: A wireless communication apparatus, which is designed to control the output power without using the power control signal sent from the base station, comprises a high-frequency power amplifier for transmission, a detection means which measures the output power of the power amplifier, and an automatic power control circuit which controls the output power of the power amplifier based on information provided by the detection means. The power amplifier includes an amplifying system which has multiple amplifying stages and is connected between the input and output terminals, and bias circuits which supply bias voltages to transistors of the respective amplifying stages. The bias circuits, which supply the bias voltages to the multiple amplifying stages excluding the last amplifying stage, are each made up of multiple resistors.Type: GrantFiled: October 31, 2001Date of Patent: August 12, 2003Assignees: Hitachi, Ltd., Hitachi Communication Systems, Inc.Inventors: Kouichi Matsushita, Tomio Furuya, Tetsuaki Adachi, Hitoshi Akamine, Nobuhiro Matsudaira
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Publication number: 20030137347Abstract: The present invention provides a high frequency power amplifier of an open-loop type, which outputs a signal having a level corresponding to an output level required under control of a power supply voltage for each output power FET, based on a control signal for the output level. The high frequency power amplifier is provided with a bias voltage generating circuit which generates a gate bias voltage of each output power FET according to an output voltage of a power control circuit for controlling the power supply voltage for the output power FET, based on the control signal for the output level.Type: ApplicationFiled: January 8, 2003Publication date: July 24, 2003Applicant: Hitachi, Ltd.Inventors: Satoshi Arai, Tsuyoshi Shibuya, Hitoshi Sekiguchi, Nobuhiro Matsudaira, Tomio Furuya, Masashi Maruyama, Yasushi Ohyama
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Publication number: 20030107433Abstract: The present invention provides a high frequency power amplifier of an open-loop type, which outputs a signal having a level corresponding to an output level required under control of a power supply voltage for each output power FET, based on a control signal for the output level. The high frequency power amplifier is provided with a bias voltage generating circuit which generates a gate bias voltage of each output power FET according to an output voltage of a power control circuit for controlling the power supply voltage for the output power FET, based on the control signal for the output level.Type: ApplicationFiled: November 15, 2002Publication date: June 12, 2003Inventors: Satoshi Arai, Tsuyoshi Shibuya, Hitoshi Sekiguchi, Nobuhiro Matsudaira, Tomio Furuya, Masashi Maruyama, Yasushi Ohyama
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Publication number: 20030016082Abstract: A multistage high frequency power amplifier circuit device has a plurality of semiconductor amplification elements connected in a cascade. The circuit device is provided with a bias control circuit used to control the bias voltage or bias current of the output semiconductor amplification element in each stage so as to reduce the variation of the output power with respect to the power control signal voltage in an area around the threshold voltage of the semiconductor amplification elements. This realizes a high frequency power amplifier circuit device provided with excellent controllability of the output power and high efficiency at the time of low power output realized with use of such a control voltage as a power control signal.Type: ApplicationFiled: June 14, 2002Publication date: January 23, 2003Inventors: Yoshikuni Matsunaga, Toshihiko Shimizu, Tomio Furuya, Nobuhiro Matsudaira, Koichi Matsushita
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Publication number: 20030001676Abstract: A module including a bias circuit that generates gate bias voltages by resistance dividers creates a problem in that the values of the resistances constituting the bias circuit must be finely adjusted, and accordingly extra trimming tasks are required. The present invention provides current generators that generate currents varying with desired characteristics responsive to a control voltage, independent of variations in transistor threshold voltages, connects output resistors to parallel transistors in respective stages to form current mirror circuits, and supplies currents from the current generators thereto to drive them, instead of supplying dividing voltages.Type: ApplicationFiled: May 17, 2002Publication date: January 2, 2003Inventors: Kouichi Matsushita, Tomio Furuya, Fuminori Morisawa, Takayuki Tsutsui, Nobuhiro Matsudaira
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Publication number: 20020057131Abstract: A wireless communication apparatus, which is designed to control the output power without using the power control signal sent from the base station, comprises a high-frequency power amplifier for transmission, a detection means which measures the output power of the power amplifier, and an automatic power control circuit which controls the output power of the power amplifier based on information provided by the detection means. The power amplifier includes an amplifying system which has multiple amplifying stages and is connected between the input and output terminals, and bias circuits which supply bias voltages to transistors of the respective amplifying stages. The bias circuits, which supply the bias voltages to the multiple amplifying stages excluding the last amplifying stage, are each made up of multiple resistors.Type: ApplicationFiled: October 31, 2001Publication date: May 16, 2002Applicant: Hitachi, Ltd.Inventors: Kouichi Matsushita, Tomio Furuya, Tetsuaki Adachi, Hitoshi Akamine, Nobuhiro Matsudaira
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Patent number: 5371755Abstract: An optical transmitter can communicate at a transmission speed exceeding Gb/s with a low bit error rate. An optical transmission module includes a semiconductor module having a semiconductor laser and an impedance matching element, a driver circuit for driving the semiconductor laser to emit an optical signal, and an optical fiber for transmitting the optical signal. The impedance matching element matches an impedance of the semiconductor laser module to an impedance of the driver circuit. The optical transmission module includes an impedance element for reducing an input impedance of the semiconductor laser module as viewed from the driving circuit in order to reduce a fall time of the optical signal. Impedance matching elements and are added to remove possible mismatching between the module and the driver circuit caused by a manufacturing error and to improve the yield of the module.Type: GrantFiled: March 5, 1993Date of Patent: December 6, 1994Assignees: Hitachi, Ltd., Hitachi Communication System Inc.Inventors: Atsushi Murata, Nobuhiro Matsudaira, Yuuki Sato