Patents by Inventor Taizo Yamawaki

Taizo Yamawaki 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).

  • Patent number: 12177790
    Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.
    Type: Grant
    Filed: February 21, 2023
    Date of Patent: December 24, 2024
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Satoshi Tanaka, Kiichiro Takenaka, Takayuki Tsutsui, Taizo Yamawaki, Shun Imai
  • Patent number: 11856525
    Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.
    Type: Grant
    Filed: May 2, 2023
    Date of Patent: December 26, 2023
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Satoshi Tanaka, Kiichiro Takenaka, Takayuki Tsutsui, Taizo Yamawaki, Shun Imai
  • Publication number: 20230276372
    Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.
    Type: Application
    Filed: May 2, 2023
    Publication date: August 31, 2023
    Inventors: Satoshi TANAKA, Kiichiro TAKENAKA, Takayuki TSUTSUI, Taizo YAMAWAKI, Shun IMAI
  • Publication number: 20230199671
    Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.
    Type: Application
    Filed: February 21, 2023
    Publication date: June 22, 2023
    Inventors: Satoshi TANAKA, Kiichiro TAKENAKA, Takayuki TSUTSUI, Taizo YAMAWAKI, Shun IMAI
  • Patent number: 11611942
    Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.
    Type: Grant
    Filed: February 23, 2022
    Date of Patent: March 21, 2023
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Satoshi Tanaka, Kiichiro Takenaka, Takayuki Tsutsui, Taizo Yamawaki, Shun Imai
  • Publication number: 20220256477
    Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.
    Type: Application
    Filed: February 23, 2022
    Publication date: August 11, 2022
    Inventors: Satoshi TANAKA, Kiichiro TAKENAKA, Takayuki TSUTSUI, Taizo YAMAWAKI, Shun IMAI
  • Patent number: 11386321
    Abstract: A neural network circuit having a plurality of analog-to-digital multipliers generates an analog product-sum voltage corresponding to the sum of charge signals of each of the analog-to-digital multipliers.
    Type: Grant
    Filed: May 14, 2019
    Date of Patent: July 12, 2022
    Assignee: HITACHI, LTD.
    Inventors: Takashi Oshima, Atsutake Kosuge, Taizo Yamawaki
  • Patent number: 11290964
    Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.
    Type: Grant
    Filed: April 13, 2021
    Date of Patent: March 29, 2022
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Satoshi Tanaka, Kiichiro Takenaka, Takayuki Tsutsui, Taizo Yamawaki, Shun Imai
  • Publication number: 20210235392
    Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.
    Type: Application
    Filed: April 13, 2021
    Publication date: July 29, 2021
    Inventors: Satoshi TANAKA, Kiichiro TAKENAKA, Takayuki TSUTSUI, Taizo YAMAWAKI, Shun IMAI
  • Patent number: 11050345
    Abstract: A power supply apparatus that can realize ripple reduction, and an electronic control unit including the power supply apparatus are provided. In view of this, a PWM controller generates a PWM signal, and a PFM controller generates a PFM signal having a phase independent of the PWM signal. A level-fixed period generating circuit sets a level-fixed period having a start timing at a selection timing set to an edge of the PFM signal. A mode selecting circuit selects, at the selection timing and as a switching control signal, the PWM signal instead of the PFM signal, and controls a logic level of the switching control signal in the level-fixed period starting at the selection timing, such that the logic level becomes a fixed logic level.
    Type: Grant
    Filed: April 24, 2018
    Date of Patent: June 29, 2021
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Ming Liu, Taizo Yamawaki, Atsushi Arata, Yasushi Sugiyama, Ryusuke Sahara
  • Patent number: 11006371
    Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.
    Type: Grant
    Filed: August 11, 2020
    Date of Patent: May 11, 2021
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Satoshi Tanaka, Kiichiro Takenaka, Takayuki Tsutsui, Taizo Yamawaki, Shun Imai
  • Publication number: 20210126527
    Abstract: A power supply apparatus that can realize ripple reduction, and an electronic control unit including the power supply apparatus are provided. In view of this, a PWM controller generates a PWM signal, and a PFM controller generates a PFM signal having a phase independent of the PWM signal. A level-fixed period generating circuit sets a level-fixed period having a start timing at a selection timing set to an edge of the PFM signal. A mode selecting circuit selects, at the selection timing and as a switching control signal, the PWM signal instead of the PFM signal, and controls a logic level of the switching control signal in the level-fixed period starting at the selection timing, such that the logic level becomes a fixed logic level.
    Type: Application
    Filed: April 24, 2018
    Publication date: April 29, 2021
    Inventors: Ming LIU, Taizo YAMAWAKI, Atsushi ARATA, Yasushi SUGIYAMA, Ryusuke SAHARA
  • Patent number: 10886970
    Abstract: A load drive system for driving a load supplied with power from a power line includes a control unit which controls switching between the power line and the load and a communication unit which communicates using voltage and current of the power line. When performing the switching, the control unit controls, based on a width of a transition period of the power-line current, the transition period being attributable to the switching, timing of the switching so as to move the transition period away from a center of a period corresponding to a symbol communicated by the communication unit.
    Type: Grant
    Filed: August 31, 2017
    Date of Patent: January 5, 2021
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Tomohiko Yano, Hiroki Yamashita, Taizo Yamawaki, Atsushi Arata, Mitsuhiko Watanabe, Ryusuke Sahara, Kenichi Hoshino
  • Publication number: 20200374811
    Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.
    Type: Application
    Filed: August 11, 2020
    Publication date: November 26, 2020
    Inventors: Satoshi TANAKA, Kiichiro TAKENAKA, Takayuki TSUTSUI, Taizo YAMAWAKI, Shun IMAI
  • Patent number: 10750454
    Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.
    Type: Grant
    Filed: January 16, 2020
    Date of Patent: August 18, 2020
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Satoshi Tanaka, Kiichiro Takenaka, Takayuki Tsutsui, Taizo Yamawaki, Shun Imai
  • Patent number: 10700741
    Abstract: A correct commutation is realized even if a communication error occurs due to a change in an actuator drive current. An electronic control unit that includes a communication section outputting a control signal and that can transmit the control signal to an actuator connected to the electronic control unit via a power line, includes an actuator operation detection section. When the actuator operation detection section detects an actuator operation, the communication section retransmits the control signal at timing of detecting the actuator operation.
    Type: Grant
    Filed: July 6, 2017
    Date of Patent: June 30, 2020
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Hiroki Yamashita, Taizo Yamawaki, Hidehiro Toyoda, Teppei Hirotsu, Ryosuke Ishida, Hirofumi Kurimoto, Kenichi Hoshino
  • Publication number: 20200154368
    Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.
    Type: Application
    Filed: January 16, 2020
    Publication date: May 14, 2020
    Inventors: Satoshi TANAKA, Kiichiro TAKENAKA, Takayuki TSUTSUI, Taizo YAMAWAKI, Shun IMAI
  • Publication number: 20200059264
    Abstract: A correct commutation is realized even if a communication error occurs due to a change in an actuator drive current. An electronic control unit that includes a communication section outputting a control signal and that can transmit the control signal to an actuator connected to the electronic control unit via a power line, includes an actuator operation detection section. When the actuator operation detection section detects an actuator operation, the communication section retransmits the control signal at timing of detecting the actuator operation.
    Type: Application
    Filed: July 6, 2017
    Publication date: February 20, 2020
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Hiroki YAMASHITA, Taizo YAMAWAKI, Hidehiro TOYODA, Teppei HIROTSU, Ryosuke ISHIDA, Hirofumi KURIMOTO, Kenichi HOSHINO
  • Patent number: 10554217
    Abstract: Provided is a sensor terminal including a sensor element, the sensor terminal further including: an ADC that converts an analog signal output from a sensor element into a digital signal; a storage device in which a plurality of first storage setting numbers being information for controlling the ADC and a plurality of pieces of first characteristic information including description of operation of the ADC are stored in association with each other; and a communication device that receives a first reception setting number from the outside of the sensor terminal, and transmits the first characteristic information corresponding to the first storage setting number that coincides with the first reception setting number, to the outside of the sensor terminal.
    Type: Grant
    Filed: December 19, 2018
    Date of Patent: February 4, 2020
    Assignee: HITACHI, LTD.
    Inventors: Yohei Nakamura, Taizo Yamawaki
  • Patent number: 10548092
    Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.
    Type: Grant
    Filed: January 9, 2019
    Date of Patent: January 28, 2020
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Satoshi Tanaka, Kiichiro Takenaka, Takayuki Tsutsui, Taizo Yamawaki, Shun Imai