Patents by Inventor Kenji Tahara

Kenji Tahara 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).

  • Publication number: 20230198481
    Abstract: Size reduction is enabled. A power amplifying circuit includes a splitter, a first amplifier, a second amplifier, and a third amplifier. The splitter splits an input signal into a first signal and a second signal. The first amplifier has a first input terminal and a first output terminal, amplifies the first signal, and outputs a first amplified signal. The second amplifier has a second input terminal and a second output terminal, amplifies the second signal, and outputs a second amplified signal. The third amplifier has a third input terminal and a third output terminal, amplifies the first signal, and outputs a third amplified signal. The first output terminal and the second output terminal are connected to each other, the third input terminal is connected to the first input terminal, and the third output terminal is connected to the second output terminal.
    Type: Application
    Filed: February 23, 2023
    Publication date: June 22, 2023
    Inventors: Kenji TAHARA, Yoshiaki SUKEMORI
  • Patent number: 11664830
    Abstract: A radio frequency module includes a transmit filter of Band A and Band B, a transmit amplifier, and a switch circuit and can perform CA using a transmit signal of Band A and a receive signal of Band B, a transmit band of Band B including a receive band of Band C. The switch circuit includes a switch switching connection between a common terminal and a first selection terminal, a switch switching connection between the common terminal and a second selection terminal, and a switch switching connection between the second selection terminal and a third selection terminal. The common terminal is connected to the transmit amplifier. The first selection terminal is connected to the transmit filter of Band A. The second selection terminal is connected to the transmit filter of Band B. The third selection terminal is connected to a receive path of Band C.
    Type: Grant
    Filed: April 11, 2022
    Date of Patent: May 30, 2023
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Kenji Tahara, Toshiki Matsui
  • Patent number: 11626967
    Abstract: A radio frequency (RF) module including a module substrate; a filter with a passband including communication band for TDD; a switch connected to the filter; a power amplifier that is arranged on a first surface of the module substrate and connected to the filter via the switch; a low-noise amplifier that is arranged on a second surface of the module substrate and connected to the filter via the switch; a filter with a passband including communication band; a low-noise amplifier that is arranged on the second surface and connected to the filter; and a conductive member arranged between the low-noise amplifiers on the second surface.
    Type: Grant
    Filed: May 7, 2021
    Date of Patent: April 11, 2023
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Kenji Tahara, Seikoh Ono, Kiyoshi Aikawa, Masanari Miura, Hiromichi Kitajima
  • Publication number: 20230079361
    Abstract: A high-frequency circuit includes: a diplexer that is composed of a filter which has a pass band including a first frequency band group and a filter which has a pass band including a second frequency band group; a notch filter that is connected with the filter and whose stop band is a frequency band which is not included in a first communication band; a notch filter that is connected with the filter and whose stop band is a frequency band which is not included in a second communication band; and switches that are connected with the notch filters. A band pass filter whose pass band is the first communication band and a band pass filter whose pass band is the second communication band are not connected between the filter and the switches.
    Type: Application
    Filed: November 18, 2022
    Publication date: March 16, 2023
    Inventors: Kenji TAHARA, Seikoh ONO, Kiyoshi AIKAWA, Masanari MIURA, Hiromichi KITAJIMA
  • Publication number: 20230016332
    Abstract: A system for performing wireless power feeding using an existing electronic device. In the present invention, a power feeder has a power feeding coil. A power receiver has a power receiving coil, a power receiving circuit unit, and a load. Electromagnetic induction using a resonance phenomenon causes the power feeder to supply an electric energy to the power receiver. A switching circuit enables the power feeding coil to periodically repeat turning on (driving state) and turning off (resonant state) of power supply. A resonant frequency of the power receiver is substantially a period combining a time of the driving state and a time of the resonant state. A resonant frequency of the power feeder is substantially a period of the time of the resonant state, and a tuning adjusting circuit performs adjustment of a resonant capacitor and a coil.
    Type: Application
    Filed: December 16, 2020
    Publication date: January 19, 2023
    Applicant: Raisontech Inc.
    Inventors: Yasushi Sekizawa, Kenji Tahara
  • Publication number: 20230013502
    Abstract: A wireless power feeding system comprising a power feeder and a power receiver including a power reception coil, a power reception circuit unit for recovering energy generated in the power reception coil, and an internal secondary battery for storing energy. Electric energy is supplied from the power feeder to the power receiver by means of electromagnetic induction using a resonance phenomenon. The power receiver has an outer shape identical to that of a conventional battery, and has a power receiver housing accommodating the power reception coil, the power reception circuit unit, and the internal secondary battery. Further, the power receiver has two electrodes disposed in positions identical to those of the conventional battery. Further, the power feeder includes a power feeding base on which the power receiver can be mounted.
    Type: Application
    Filed: February 17, 2020
    Publication date: January 19, 2023
    Applicant: Raisontech Inc.
    Inventors: Yasushi Sekizawa, Kenji Tahara
  • Publication number: 20220376665
    Abstract: The present disclosure facilitates impedance matching between a power amplifier and filters. A radio-frequency circuit includes a power amplifier, a plurality of transmit filters, a switch, a plurality of first matching networks, and a second matching network. The switch switches the plurality of transmit filters to be coupled to the power amplifier. The plurality of first matching networks are coupled between the plurality of transmit filters and the switch. The second matching network is coupled between the power amplifier and the switch. The second matching network includes a transmission line transformer.
    Type: Application
    Filed: August 3, 2022
    Publication date: November 24, 2022
    Inventors: Kenji TAHARA, Syunji YOSHIMI, Kazuhiro IKARASHI, Yusuke TANAKA, Kenichi SHIMAMOTO, Masatoshi HASE
  • Publication number: 20220368284
    Abstract: A current flowing through a transistor of a final-stage amplifier is suppressed. A power amplification circuit includes a driving-stage amplifier, a final-stage amplifier, a power supply terminal, a first voltage control circuit, and a second voltage control circuit. The driving-stage amplifier includes a first transistor having a first input terminal, a first output terminal, and a first ground terminal. The final-stage amplifier includes a second transistor having a second input terminal, a second output terminal, and a second ground terminal. The first voltage control circuit is connected between the power supply terminal and the first output terminal, and controls a first power supply voltage applied to the first transistor. The second voltage control circuit is connected between the power supply terminal and the second output terminal, and controls a second power supply voltage applied to the second transistor.
    Type: Application
    Filed: July 27, 2022
    Publication date: November 17, 2022
    Inventors: Kenji TAHARA, Yusuke TANAKA, Yoshiaki SUKEMORI
  • Publication number: 20220311388
    Abstract: A higher-speed operation of a power amplifier circuit is achieved. A power amplifier circuit includes multi-stage amplifier units, an ET terminal, and an APT terminal. The multi-stage amplifier units include a final-stage amplifier unit. The final-stage amplifier unit includes a first amplifier element and a second amplifier element that are connected in parallel with each other. The first amplifier element is connected to the ET terminal. The second amplifier element is connected to the APT terminal.
    Type: Application
    Filed: June 7, 2022
    Publication date: September 29, 2022
    Inventors: Kenji TAHARA, Yoshihiro DAIMON
  • Publication number: 20220311455
    Abstract: The sensitivity of a reception filter for receiving a reception signal in a second frequency band corresponding to the 4G or 5G standard is prevented from being degraded by a harmonic of a third transmission signal in a third frequency region corresponding to the 4G or 5G standard. A radio-frequency circuit includes an antenna terminal, a relay terminal, a transmission filter, a reception filter, a variable low-pass filter, and a switch. A first transmission signal in a first frequency band is input to the relay terminal. In communication using the first frequency band, the variable low-pass filter passes the first transmission signal input via the relay terminal. When another harmonic circuit performs communication using the third frequency band, the variable low-pass filter attenuates, among harmonics of the third transmission signal in the third frequency band, a harmonic input via the relay terminal.
    Type: Application
    Filed: June 6, 2022
    Publication date: September 29, 2022
    Inventors: Kenji TAHARA, Takahiro EGUCHI, Hiroyuki NAGAMORI
  • Publication number: 20220311395
    Abstract: Gain is suppressed. In a power amplification circuit, a first transistor has a first input terminal, a first output terminal, and a first ground terminal. A second transistor has a second input terminal, a second output terminal, and a second ground terminal. The second input terminal is connected to the first input terminal. The second output terminal is connected to the first output terminal. A first bias circuit is connected to the first input terminal. A second bias circuit is connected to the second input terminal. A first resistor is connected between the first ground terminal and the ground. A second resistor is connected between the second ground terminal and the ground. The second resistor has a resistance value greater than that of the first resistor.
    Type: Application
    Filed: June 16, 2022
    Publication date: September 29, 2022
    Inventors: Kenji TAHARA, Kenichi SHIMAMOTO, Takashi YAMADA
  • Publication number: 20220294401
    Abstract: Increase in power-added efficiency can be achieved. A second base of a second transistor is connected to a first collector of a first transistor. A third base of a third transistor is connected to the first collector of the first transistor, and a third collector of the third transistor is connected to a second collector of the second transistor. A second bias circuit includes a fifth transistor connected to the second base of the second transistor. A third bias circuit includes a sixth transistor connected to the third base of the third transistor. A first current limiting circuit includes a seventh transistor, a first collector resistor, and a first base resistor. A second current limiting circuit includes an eighth transistor, a second collector resistor, and a second base resistor.
    Type: Application
    Filed: June 3, 2022
    Publication date: September 15, 2022
    Inventors: Kenji Tahara, Kenichi Shimamoto, Yusuke Tanaka
  • Patent number: 11418158
    Abstract: A first power amplifier amplifies first transmission signals in a first frequency band and outputs the resultant signals. A first matching circuit includes a plurality of first inductor portions and is connected to an output pad electrode of the first power amplifier. A second power amplifier amplifies second transmission signals in a second frequency band higher than the first frequency band and outputs the resultant signals. A second matching circuit includes at least one second inductor portion and is connected to an output side of the second power amplifier. A multilayer substrate has a first main surface and a second main surface located opposite to each other and is provided with the first and second power amplifiers and the first and second matching circuits. The first inductor portion closer than the other first inductor portions to the output pad electrode includes an inner-layer inductor portion located in the multilayer substrate.
    Type: Grant
    Filed: April 1, 2020
    Date of Patent: August 16, 2022
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Yoshihiro Daimon, Kenji Tahara
  • Publication number: 20220239318
    Abstract: A radio frequency module includes a transmit filter of Band A and Band B, a transmit amplifier, and a switch circuit and can perform CA using a transmit signal of Band A and a receive signal of Band B, a transmit band of Band B including a receive band of Band C. The switch circuit includes a switch switching connection between a common terminal and a first selection terminal, a switch switching connection between the common terminal and a second selection terminal, and a switch switching connection between the second selection terminal and a third selection terminal. The common terminal is connected to the transmit amplifier. The first selection terminal is connected to the transmit filter of Band A. The second selection terminal is connected to the transmit filter of Band B. The third selection terminal is connected to a receive path of Band C.
    Type: Application
    Filed: April 11, 2022
    Publication date: July 28, 2022
    Inventors: Kenji TAHARA, Toshiki MATSUI
  • Publication number: 20220178530
    Abstract: A light unit is replaced in the water, and power is supplied without an electrical contact. A composite wireless power feeding system includes a first wireless power feeding system including a first power feeding coil, a first power feeding circuit unit, a first power reception coil, a first power reception circuit unit, and a first battery, and a second wireless power feeding system including a second power feeding coil, a second power feeding circuit unit, a second power reception coil, a second power reception circuit unit, and an energy consumption circuit unit. The first power reception coil is also used as the second power feeding coil. The first battery is a power source that causes the second power feeding coil to generate electromagnetic waves. The second power feeding circuit unit and the first power reception circuit unit are mounted on one circuit board, such that switching between a power feeding mode and a power reception mode can be performed by predetermined mode switching means.
    Type: Application
    Filed: March 24, 2020
    Publication date: June 9, 2022
    Inventors: YOSHINORI KUNO, YASUSHI SEKIZAWA, KENJI TAHARA
  • Patent number: 11349521
    Abstract: A radio-frequency signal transmitting and receiving circuit includes a power amplifier, a transmission band pass filter configured to transmit a radio-frequency input signal, a first reception band pass filter configured to transmit a first radio-frequency reception signal, a first low-noise amplifier configured to amplify the first radio-frequency reception signal and output a first radio-frequency output signal, a first transmitting and receiving filter having a first end and a second end, the first end being electrically connected to a first antenna terminal, and a switch configured to electrically connect the transmission band pass filter to the second end of the first transmitting and receiving filter to output the radio-frequency input signal to the first antenna terminal and electrically connect the second end of the first transmitting and receiving filter to the first reception band pass filter to receive the first radio-frequency reception signal from the first antenna terminal.
    Type: Grant
    Filed: April 20, 2021
    Date of Patent: May 31, 2022
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Kenji Tahara, Seikoh Ono, Kunihiro Watanabe, Hiroshi Masuda, Naohide Tomita, Takeshi Kogure, Yusuke Tanaka
  • Patent number: 11329675
    Abstract: A radio frequency module includes a transmit filter of Band A and Band B, a transmit amplifier, and a switch circuit and can perform CA using a transmit signal of Band A and a receive signal of Band B, a transmit band of Band B including a receive band of Band C. The switch circuit includes a switch switching connection between a common terminal and a first selection terminal, a switch switching connection between the common terminal and a second selection terminal, and a switch switching connection between the second selection terminal and a third selection terminal. The common terminal is connected to the transmit amplifier. The first selection terminal is connected to the transmit filter of Band A. The second selection terminal is connected to the transmit filter of Band B. The third selection terminal is connected to a receive path of Band C.
    Type: Grant
    Filed: October 15, 2020
    Date of Patent: May 10, 2022
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventor: Kenji Tahara
  • Patent number: 11323193
    Abstract: A filter circuit includes a first switch circuit that exclusively connects a first common terminal to either of a first selection terminal and a second selection terminal; a first signal terminal that is connected to the first selection terminal and that is for communicating a first communication signal belonging to a first frequency range, which is a frequency range of a first communication band; a second signal terminal that is connected to the second selection terminal and that is for communicating a second communication signal belonging to a second frequency range, which is the frequency range of a second communication band and which is at least partially overlapped with the first frequency range; and a first band pass filter one end of which is connected to the first common terminal and which uses both the first frequency range and the second frequency range as pass bands.
    Type: Grant
    Filed: March 18, 2020
    Date of Patent: May 3, 2022
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Kenji Tahara, Shou Matsumoto
  • Patent number: 11290134
    Abstract: Opposite-side frequency bands are opened in a plurality of carrier aggregations. In a radio frequency module, a variable phase shifter differentiates a phase in a first single mode in which signals of a first frequency band are communicated and a phase in a first carrier aggregation mode and differentiates the phase in the first single mode and a phase in a second carrier aggregation mode. The variable phase shifter makes a phase difference between the phase in the first single mode and the phase in the first carrier aggregation mode different from a phase difference between the phase in the first single mode and the phase in the second carrier aggregation mode.
    Type: Grant
    Filed: September 17, 2020
    Date of Patent: March 29, 2022
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Kenji Tahara, Reiji Nakajima
  • Publication number: 20220021510
    Abstract: A radio frequency (RF) module including a module substrate; a filter with a passband including communication band for TDD; a switch connected to the filter; a power amplifier that is arranged on a first surface of the module substrate and connected to the filter via the switch; a low-noise amplifier that is arranged on a second surface of the module substrate and connected to the filter via the switch; a filter with a passband including communication band; a low-noise amplifier that is arranged on the second surface and connected to the filter; and a conductive member arranged between the low-noise amplifiers on the second surface.
    Type: Application
    Filed: May 7, 2021
    Publication date: January 20, 2022
    Applicant: Murata Manufacturing Co., Ltd.
    Inventors: Kenji TAHARA, Seikoh ONO, Kiyoshi AIKAWA, Masanari MIURA, Hiromichi KITAJIMA