Patents by Inventor Takuji Mochizuki

Takuji Mochizuki 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: 20240120634
    Abstract: To provide an antenna apparatus and a radome that are capable of suppressing an increase in size of the antenna apparatus, an antenna apparatus (100) includes a substrate (10) in which a plurality of antenna elements (20) are disposed on a first surface, and a radome (50) having thermal conductivity, which covers the substrate (10) and forms a plurality of slots (53) at positions facing each of the plurality of antenna elements (20). The radome (50) includes a heat radiation fin (56) protruding to an opposite side to the first surface side, and a wall portion (52) being provided between an antenna element (20) and an antenna element (20) being adjacent to the antenna element (20), and being capable of transferring heat of a heat generating component (40) connected to the substrate (10) to the heat radiation fin (56).
    Type: Application
    Filed: November 10, 2021
    Publication date: April 11, 2024
    Applicant: Nec Corporation
    Inventors: Takuji Mochizuki, Yoshihide Takahashi
  • Publication number: 20240089877
    Abstract: In a wireless communication apparatus according to the present disclosure, a determination unit detects presence or absence of a transmission signal for each transmission symbol in each of a plurality of transmitters. In response to detection of presence of the transmission signal at any transmitter of the plurality of transmitters and absence of the transmission signal at all of the plurality of transmitters in a transmission symbol before a transmission symbol to which the any transmitter transmits a transmission signal, the determination unit causes a stabilization signal to pass through the any transmitter and any transmission amplifier before the transmission signal passes through the any transmitter and the any transmission amplifier by inserting the stabilization signal for stabilizing characteristics of the any transmission amplifier associated to the any transmitter into a time domain preceding a time domain of the transmission signal.
    Type: Application
    Filed: June 2, 2023
    Publication date: March 14, 2024
    Applicant: NEC Corporation
    Inventor: Takuji Mochizuki
  • Publication number: 20240072832
    Abstract: A signal processing device according to an example embodiment includes: a distortion compensation circuit configured to execute distortion compensation processing of compensating for nonlinear distortion on an input signal, and output a signal subjected to the distortion compensation processing; an amplifier configured to amplify the signal output from the distortion compensation circuit and output the amplified signal as a communication signal; and a signal output circuit configured to output an adjustment signal for adjusting the distortion compensation processing to the distortion compensation circuit as the input signal at a timing at which the communication signal is not output, the adjustment signal having a frequency band that covers a frequency band of the communication signal.
    Type: Application
    Filed: May 25, 2021
    Publication date: February 29, 2024
    Applicant: NEC Corporation
    Inventors: Takuji Mochizuki, Kazuhiro Ishida
  • Publication number: 20240056111
    Abstract: A signal processing device according to an example embodiment includes: a distortion compensation circuit configured to output a signal subjected to distortion compensation processing; a plurality of amplifiers configured to amplify the plurality of input signals including the signal output from the distortion compensation circuit and output the amplified signals as output signals; a calculation circuit configured to calculate a comparison result for at least one of a phase, an amplitude, or an intensity between the input signal and the output signal corresponding to the input signal during a calibration operation of the signal processing device in which calibration signals are used as the plurality of input signals and are input to the plurality of amplifiers; and a controller configured to control whether or not the distortion compensation circuit executes the distortion compensation processing on the calibration signals based on the calculated comparison result.
    Type: Application
    Filed: November 16, 2021
    Publication date: February 15, 2024
    Applicant: NEC Corporation
    Inventor: Takuji Mochizuki
  • Patent number: 11689299
    Abstract: A wireless communication apparatus includes: a plurality of receivers provided so as to correspond to a plurality of respective antennas; a calibration transmitter; and a control unit configured to release, when a UL calibration is executed, connection between the antennas and the respective receivers, and determine a calibration weight to be applied to each of the receivers based on a UL calibration signal transmitted from the calibration transmitter and a UL calibration signal received by each of the receivers.
    Type: Grant
    Filed: June 10, 2019
    Date of Patent: June 27, 2023
    Assignee: NEC CORPORATION
    Inventor: Takuji Mochizuki
  • Publication number: 20230188226
    Abstract: A controller performs an intra-subunit transmission calibration to compensate for relative differences in amplitude and phase among multiple transmitter RF chains within each subunit of an active antenna system (AAS). The controller further performs inter-subunit transmission calibration to compensate for relative differences in amplitude and phase among multiple representative transmitter RF chains, each included in a respective one of the multiple subunits.
    Type: Application
    Filed: December 8, 2022
    Publication date: June 15, 2023
    Applicant: NEC Corporation
    Inventor: Takuji MOCHIZUKI
  • Patent number: 11581956
    Abstract: One of a plurality of radio communication apparatuses (100) becomes a master apparatus (100-M), and a rest of them become slave apparatuses (100-S). The master apparatus and each of the slave apparatus includes a plurality of transceivers (31) each composed of a transmitter and a receiver and first ports (55 and 56). The master apparatus further includes a calibration transceiver (51). The first port of the master apparatus is connected to the first port of the slave apparatus via an RF cable. When transmission calibration is performed, each transmitter of the slave apparatus transmits a transmission calibration signal to the calibration transceiver of the master apparatus via the RF cable. When reception calibration is performed, the calibration transceiver of the master apparatus transmits a reception calibration signal to each receiver of the slave apparatus via the RF cable.
    Type: Grant
    Filed: February 6, 2019
    Date of Patent: February 14, 2023
    Assignee: NEC CORPORATION
    Inventor: Takuji Mochizuki
  • Patent number: 11502405
    Abstract: A transmission/reception baseband-processing device includes a calibration-processing unit configured to correct an input signal input to a transmission unit on the basis of a first characteristic according to characteristics of the transmission unit of a transmission/reception front end-processing unit and a calibration reception unit that is a reception unit of a calibration transmission/reception unit and a second characteristic according to a characteristic of the calibration reception unit.
    Type: Grant
    Filed: October 1, 2019
    Date of Patent: November 15, 2022
    Assignee: NEC CORPORATION
    Inventor: Takuji Mochizuki
  • Patent number: 11456762
    Abstract: A control unit (control device) (12) is configured to be connectable to radio units (11-1 to 11-N), respectively, and each path unit (13) includes path units (13-1 to 13-N) having a first input path (L1) and a second input path (L2). The first input path (L1) is a path on which a corresponding DPD unit (14) is provided and through which a transmission baseband signal compensated for the non-linear distortion is input to a corresponding radio unit (11). The second input path (L2) is a path through which a transmission calibration signal for calibrating a path and amplitude deviation between the radio units (11) is input to the corresponding radio unit (11) without passing through the DPD unit (14).
    Type: Grant
    Filed: August 21, 2019
    Date of Patent: September 27, 2022
    Assignee: NEC CORPORATION
    Inventor: Takuji Mochizuki
  • Publication number: 20220285853
    Abstract: A wireless communication device (500) according to the present disclosure includes a plurality of antennas (520#n), a plurality of transmitter-receivers (TRX#n) that are provided in association with each of the plurality of antennas (520#n), and each include a transmitter (TX#n) and a receiver (RX#n), a calibration transmitter-receiver (CAL-TRX), a distribution synthesis unit (530), and a control unit (510). The control unit (510) causes a transmission calibration signal to be transmitted to each transmitter (TX#n) to be orthogonalized in frequency for each transmitter (TX#n). Each transmitter (TX#n) sends the transmission calibration signal being orthogonalized in frequency. The distribution synthesis unit (530) synthesizes the transmission calibration signals being transmitted from the transmitters (TX#n), and transmits the synthesized signal to the calibration transmitter-receiver (CAL-TRX).
    Type: Application
    Filed: May 26, 2020
    Publication date: September 8, 2022
    Applicant: NEC Corporation
    Inventor: Takuji MOCHIZUKI
  • Publication number: 20210391879
    Abstract: A control unit (control device) (12) is configured to be connectable to radio units (11-1 to 11-N), respectively, and each path unit (13) includes path units (13-1 to 13-N) having a first input path (L1) and a second input path (L2). The first input path (L1) is a path on which a corresponding DPD unit (14) is provided and through which a transmission baseband signal compensated for the non-linear distortion is input to a corresponding radio unit (11). The second input path (L2) is a path through which a transmission calibration signal for calibrating a path and amplitude deviation between the radio units (11) is input to the corresponding radio unit (11) without passing through the DPD unit (14).
    Type: Application
    Filed: August 21, 2019
    Publication date: December 16, 2021
    Applicant: NEC Corporation
    Inventor: Takuji MOCHIZUKI
  • Patent number: 10944489
    Abstract: An active antenna system includes: a plurality of antennas; a plurality of switches respectively connected to the antennas, the switches being configured to switch between transmission signal lines and reception signal lines to perform Time Division Duplex; a plurality of transmitter-receivers respectively connected to the transmission signal lines and the reception signal lines; a calibration transmitter connected to the transmission signal lines; a calibration receiver connected to the reception signal lines; and a control unit configured to carry out, during a receiving time of the Time Division Duplex, reception calibration of each of the transmitter-receivers based on a signal transmitted by the calibration transmitter and received by the transmitter-receivers, and, during a transition time from reception to transmission, carry out transmission calibration of each of the transmitter-receivers based on a signal transmitted by the transmitter-receivers and received by the calibration receiver.
    Type: Grant
    Filed: July 30, 2018
    Date of Patent: March 9, 2021
    Assignee: NEC CORPORATION
    Inventor: Takuji Mochizuki
  • Publication number: 20210036787
    Abstract: One of a plurality of radio communication apparatuses (100) becomes a master apparatus (100-M), and a rest of them become slave apparatuses (100-S). The master apparatus and each of the slave apparatus includes a plurality of transceivers (31) each composed of a transmitter and a receiver and first ports (55 and 56). The master apparatus further includes a calibration transceiver (51). The first port of the master apparatus is connected to the first port of the slave apparatus via an RF cable. When transmission calibration is performed, each transmitter of the slave apparatus transmits a transmission calibration signal to the calibration transceiver of the master apparatus via the RF cable. When reception calibration is performed, the calibration transceiver of the master apparatus transmits a reception calibration signal to each receiver of the slave apparatus via the RF cable.
    Type: Application
    Filed: February 6, 2019
    Publication date: February 4, 2021
    Applicant: NEC CORPORATION
    Inventor: Takuji MOCHIZUKI
  • Patent number: 10791015
    Abstract: A wireless communication apparatus includes amplifiers, peak component suppression units respectively corresponding to the amplifiers and configured to suppress, down to a first threshold, a peak level of a composite signal in which transmission signals to be transmitted to a plurality of terminals are superimposed, a detection unit configured to detect transmission power of the composite signal input to each of the peak component suppression units, and a control unit configured to perform at least one of control of the first threshold of each peak component suppression unit and a saturation point of an amplifier corresponding to each peak component suppression unit and control of the transmission power of the composite signal in accordance with the transmission power detected by the detection unit.
    Type: Grant
    Filed: June 13, 2019
    Date of Patent: September 29, 2020
    Assignee: NEC CORPORATION
    Inventor: Takuji Mochizuki
  • Publication number: 20200112096
    Abstract: A transmission/reception baseband-processing device includes a calibration-processing unit configured to correct an input signal input to a transmission unit on the basis of a first characteristic according to characteristics of the transmission unit of a transmission/reception front end-processing unit and a calibration reception unit that is a reception unit of a calibration transmission/reception unit and a second characteristic according to a characteristic of the calibration reception unit.
    Type: Application
    Filed: October 1, 2019
    Publication date: April 9, 2020
    Applicant: NEC Corporation
    Inventor: Takuji Mochizuki
  • Publication number: 20190386865
    Abstract: A wireless communication apparatus includes amplifiers, peak component suppression units respectively corresponding to the amplifiers and configured to suppress, down to a first threshold, a peak level of a composite signal in which transmission signals to be transmitted to a plurality of terminals are superimposed, a detection unit configured to detect transmission power of the composite signal input to each of the peak component suppression units, and a control unit configured to perform at least one of control of the first threshold of each peak component suppression unit and a saturation point of an amplifier corresponding to each peak component suppression unit and control of the transmission power of the composite signal in accordance with the transmission power detected by the detection unit.
    Type: Application
    Filed: June 13, 2019
    Publication date: December 19, 2019
    Applicant: NEC CORPORATION
    Inventor: Takuji MOCHIZUKI
  • Publication number: 20190386751
    Abstract: A wireless communication apparatus includes: a plurality of receivers provided so as to correspond to a plurality of respective antennas; a calibration transmitter; and a control unit configured to release, when a UL calibration is executed, connection between the antennas and the respective receivers, and determine a calibration weight to be applied to each of the receivers based on a UL calibration signal transmitted from the calibration transmitter and a UL calibration signal received by each of the receivers.
    Type: Application
    Filed: June 10, 2019
    Publication date: December 19, 2019
    Applicant: NEC Corporation
    Inventor: Takuji MOCHIZUKI
  • Patent number: 10404656
    Abstract: [Problem] To provide an antenna system that excellently dissipates heat to the outside of a housing, said heat having been generated by means of an electronic component. [Solution] An electronic circuit board 10 has an electronic component mounted thereon, and has an antenna that is formed on one surface. A protection member 20 covers the one surface of the electric circuit board 10. A heat transfer unit 30 transfers heat to the protection member 20, said heat having been generated by means of the electronic component mounted on the electric circuit board 10.
    Type: Grant
    Filed: March 16, 2015
    Date of Patent: September 3, 2019
    Assignee: NEC Corporation
    Inventor: Takuji Mochizuki
  • Publication number: 20190044624
    Abstract: An active antenna system includes: a plurality of antennas; a plurality of switches respectively connected to the antennas, the switches being configured to switch between transmission signal lines and reception signal lines to perform Time Division Duplex; a plurality of transmitter-receivers respectively connected to the transmission signal lines and the reception signal lines; a calibration transmitter connected to the transmission signal lines; a calibration receiver connected to the reception signal lines; and a control unit configured to carry out, during a receiving time of the Time Division Duplex, reception calibration of each of the transmitter-receivers based on a signal transmitted by the calibration transmitter and received by the transmitter-receivers, and, during a transition time from reception to transmission, carry out transmission calibration of each of the transmitter-receivers based on a signal transmitted by the transmitter-receivers and received by the calibration receiver.
    Type: Application
    Filed: July 30, 2018
    Publication date: February 7, 2019
    Applicant: NEC CORPORATION
    Inventor: Takuji MOCHIZUKI
  • Patent number: 9560541
    Abstract: A wireless transmission device (100) of the invention includes a VSWR measuring means (101) which measures VSWR; and a VSWR determining means (102) which determines reliability of a measurement value of the VSWR measured by the VSWR measuring means (101). The VSWR determining means (102) includes a baseband signal analyzing means (90) which analyzes a baseband signal by detecting a difference between the baseband signal, and a delay signal of the baseband signal; a baseband signal density determining means (19) which determines a density of the baseband signal, based on the difference between the baseband signal and the delay signal analyzed by the baseband signal analyzing means (90), and a VSWR output switching means (13) which restrains output of the VSWR measuring means, when the baseband signal density determining means (19) determines that the density of the baseband signal is low.
    Type: Grant
    Filed: April 26, 2013
    Date of Patent: January 31, 2017
    Assignee: NEC Corporation
    Inventor: Takuji Mochizuki