Patents by Inventor Koji Tsutsumi

Koji Tsutsumi 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: 11949394
    Abstract: A first phase shift circuit amplifies, when a first signal, a second signal having a phase difference of 90 degrees from the first signal, a third signal having a phase difference of 180 degrees from the first signal, and a fourth signal having a phase difference of 270 degrees from the first signal are output from a 90-degree distributor that distributes an input signal, each of any three signals from among the first signal to the fourth signal. A second phase shift circuit amplifies each of any two signals of any three signals and one signal that is not amplified by the first phase shift circuit from among the first signal to the fourth signal. One or more phase shift circuits of the first phase shift circuit and the second phase shift circuit each include a compensation circuit that compensates for a phase error of the synthesized signal.
    Type: Grant
    Filed: June 22, 2022
    Date of Patent: April 2, 2024
    Assignee: Mitsubishi Electric Corporation
    Inventors: Wataru Yamamoto, Koji Tsutsumi, Masaomi Tsuru
  • Patent number: 11929723
    Abstract: A phase-variable frequency multiplier includes: a 90-degree divider for dividing an input signal into an I-signal and a Q-signal; an amplitude setting circuit for distributing each of the I-signal and the Q-signal to two paths, setting amplitudes of two of four signals including the two distributed I-signals and the two distributed Q-signals depending on a phase shift amount of the input signal, and outputting as set signals, the four signals including the signals with the set amplitudes; a first mixer for multiplying one of the two I-signals included in the set signals by one of the two Q-signals included in the set signals to generate a first signal having a frequency being twice the frequency of the input signal; a second mixer for multiplying the other of the two I-signals included in the set signals by the other of the two Q-signals included in the set signals to generate a second signal with an amplitude ratio with respect to the first signal, being a tangent or a reciprocal of a tangent of the phase sh
    Type: Grant
    Filed: August 18, 2021
    Date of Patent: March 12, 2024
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Wataru Yamamoto, Koji Tsutsumi, Sho Ikeda, Masaomi Tsuru
  • Patent number: 11870447
    Abstract: A third signal having a phase intermediate between a first signal based on a reference signal and a second signal with a phase shifted by an element of a previous stage is generated, a signal obtained by shifting the phase of the third signal by a first phase shill amount is output as a second signal to an element of a subsequent stage, a phase difference between the third signal and a fourth signal obtained by shifting the phase of a first signal output from the element of the subsequent stage by the first phase shift amount is detected, and the first phase shift amount is controlled on the basis of the detected phase difference.
    Type: Grant
    Filed: October 18, 2021
    Date of Patent: January 9, 2024
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Sho Ikeda, Akihito Hirai, Koji Tsutsumi, Masaomi Tsuru
  • Patent number: 11841457
    Abstract: A radar device includes a transmission module, a reception module, and a signal processing unit. The transmission module includes an RF signal source that generates a transmission chirp signal synchronized with a reference signal. The reception module includes an RF signal source that generates a reception chirp signal used as a reception local signal and synchronized with the reference signal. The reception module receives a reflected wave of the transmission chirp signal emitted from the transmission module, and mixes a received reception signal with the reception chirp signal. The signal processing unit detects a target based on a beat signal generated by the mixing by the reception module.
    Type: Grant
    Filed: December 1, 2020
    Date of Patent: December 12, 2023
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Koji Tsutsumi, Tatsuya Hagiwara, Mitsuhiro Shimozawa
  • Patent number: 11757454
    Abstract: A delay synchronization circuit includes a pulse synthesizing circuit to generate a synthesized signal including a first pulse signal synchronized with a reference signal and a second pulse signal synchronized a feedback signal, a VCDL to delay the synthesized signal g and output a delayed synthesized signal, a pulse separation circuit to generate a first separation signal synchronized with a first pulse signal included in the delayed synthesized signal and generate a second separation signal synchronized with a second pulse signal included in the delayed synthesized signal, a circulator to output a first separation signal to a clock reception circuit and then output the first separation signal returned from the clock reception circuit to the pulse synthesizing circuit as the feedback signal, and a delay-amount control circuit to control a delay amount of the delayed synthesized signal according to a phase difference between the reference signal and the second separation signal.
    Type: Grant
    Filed: September 20, 2022
    Date of Patent: September 12, 2023
    Assignee: Mitsubishi Electric Corporation
    Inventors: Sho Ikeda, Koji Tsutsumi, Masaomi Tsuru
  • Publication number: 20230017177
    Abstract: A delay synchronization circuit includes a pulse synthesizing circuit to generate a synthesized signal including a first pulse signal synchronized with a reference signal and a second pulse signal synchronized a feedback signal, a VCDL to delay the synthesized signal g and output a delayed synthesized signal, a pulse separation circuit to generate a first separation signal synchronized with a first pulse signal included in the delayed synthesized signal and generate a second separation signal synchronized with a second pulse signal included in the delayed synthesized signal, a circulator to output a first separation signal to a clock reception circuit and then output the first separation signal returned from the clock reception circuit to the pulse synthesizing circuit as the feedback signal, and a delay-amount control circuit to control a delay amount of the delayed synthesized signal according to a phase difference between the reference signal and the second separation signal.
    Type: Application
    Filed: September 20, 2022
    Publication date: January 19, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventors: Sho IKEDA, Koji TSUTSUMI, Masaomi TSURU
  • Patent number: 11502656
    Abstract: A variable gain amplifier includes a first transistor group which is connected to an input terminal and an output terminal, and which amplifies a signal from the input terminal to output the amplified signal to the output terminal; a second transistor group connected to the input terminal; a third transistor group connected to the output terminal; and a controller configured to control the first transistor group, the second transistor group, and the third transistor group so that a total number of the number of transistors to be turned on in the first transistor group and the second transistor group is kept at a constant value, and total numbers of transistors to be turned on in the first transistor group and in the third transistor group are the same.
    Type: Grant
    Filed: December 15, 2020
    Date of Patent: November 15, 2022
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Wataru Yamamoto, Koji Tsutsumi, Mitsuhiro Shimozawa
  • Publication number: 20220349992
    Abstract: In a radar device, a reception antenna directly receives a chirp signal transmitted by a transmission antenna of a module other than a module to which the reception antenna belongs among a plurality of modules, a mixer generates a baseband signal by mixing a chirp signal generated by a chirp signal source and a chirp signal received by the reception antenna, and an analog-to-digital converter generates a digital signal by digital-converting the baseband signal generated by the mixer.
    Type: Application
    Filed: July 18, 2022
    Publication date: November 3, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Koji TSUTSUMI, Sho IKEDA
  • Publication number: 20220329231
    Abstract: A first phase shift circuit amplifies, when a first signal, a second signal having a phase difference of 90 degrees from the first signal, a third signal having a phase difference of 180 degrees from the first signal, and a fourth signal having a phase difference of 270 degrees from the first signal are output from a 90-degree distributor that distributes an input signal, each of any three signals from among the first signal to the fourth signal. A second phase shift circuit amplifies each of any two signals of any three signals and one signal that is not amplified by the first phase shift circuit from among the first signal to the fourth signal. One or more phase shift circuits of the first phase shift circuit and the second phase shift circuit each include a compensation circuit that compensates for a phase error of the synthesized signal.
    Type: Application
    Filed: June 22, 2022
    Publication date: October 13, 2022
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Wataru YAMAMOTO, Koji TSUTSUMI, Masaomi TSURU
  • Patent number: 11283455
    Abstract: A lock detection circuit is configured to include an integrating circuit that integrates a phase difference between a frequency-divided signal of a VCO and a reference signal during a constant period within a transient response period for an output signal from the VCO, and integrates a phase difference between the frequency-divided signal and the reference signal during a constant period within a convergence period for the output signal from the VCO; and a degree-of-convergence calculating circuit that calculates a degree at which the output signal from the VCO has converged, from a result of the integration of the phase difference obtained by the integrating circuit during the constant period within the transient response period and a result of the integration of the phase difference obtained by the integrating circuit during the constant period within the convergence period.
    Type: Grant
    Filed: March 24, 2021
    Date of Patent: March 22, 2022
    Assignee: Mitsubishi Electric Corporation
    Inventors: Koji Tsutsumi, Sho Ikeda
  • Publication number: 20220052699
    Abstract: A third signal having a phase intermediate between a first signal based on a reference signal and a second signal with a phase shifted by an element of a previous stage is generated, a signal obtained by shifting the phase of the third signal by a first phase shill amount is output as a second signal to an element of a subsequent stage, a phase difference between the third signal and a fourth signal obtained by shifting the phase of a first signal output from the element of the subsequent stage by the first phase shift amount is detected, and the first phase shift amount is controlled on the basis of the detected phase difference.
    Type: Application
    Filed: October 18, 2021
    Publication date: February 17, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Sho IKEDA, Akihito HIRAI, Koji TSUTSUMI, Masaomi TSURU
  • Publication number: 20210376817
    Abstract: A phase-variable frequency multiplier includes: a 90-degree divider for dividing an input signal into an I-signal and a Q-signal; an amplitude setting circuit for distributing each of the I-signal and the Q-signal to two paths, setting amplitudes of two of four signals including the two distributed I-signals and the two distributed Q-signals depending on a phase shift amount of the input signal, and outputting as set signals, the four signals including the signals with the set amplitudes; a first mixer for multiplying one of the two I-signals included in the set signals by one of the two Q-signals included in the set signals to generate a first signal having a frequency being twice the frequency of the input signal; a second mixer for multiplying the other of the two I-signals included in the set signals by the other of the two Q-signals included in the set signals to generate a second signal with an amplitude ratio with respect to the first signal, being a tangent or a reciprocal of a tangent of the phase sh
    Type: Application
    Filed: August 18, 2021
    Publication date: December 2, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Wataru YAMAMOTO, Koji TSUTSUMI, Sho IKEDA, Masaomi TSURU
  • Patent number: 11088697
    Abstract: A phase-frequency comparator compares a reference signal with an output signal from a variable frequency divider, and outputs an up signal of frequency and a down signal of frequency depending on results of the comparison. An AND circuit performs an AND operation between the up signal and the down signal, and outputs a result of the operation as a retiming si al CLKretime. A flip-flop circuit holds an output signal from a frequency control circuit at timing of the output signal from the AND circuit, and outputs the held output signal. At ?? modulator determines a division ratio for the variable frequency divider on the basis of the output from the flip-flop circuit.
    Type: Grant
    Filed: July 4, 2017
    Date of Patent: August 10, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Koji Tsutsumi, Yuki Yanagihara, Mitsuhiro Shimozawa
  • Patent number: 11088698
    Abstract: A phase-locked loop circuit includes: a division ratio control circuit controlling a division ratio of an output signal of a variable frequency divider on the basis of an addition signal of a negative feedback signal and a division ratio setting signal indicating the division ratio, in synchronization with a divided signal output from the variable frequency divider; a first phase detection circuit calculating a first phase detection signal indicating a phase of an output signal of a signal output circuit; a second phase detection circuit calculating a second phase detection signal indicating a phase of the output signal of a case where it is assumed that the division ratio control circuit controls the division ratio of the output signal of the variable frequency divider in synchronization with the reference signal; and a shift circuit generating a negative feedback signal from a difference between the first phase detection signal and the second phase detection signal, and outputting an addition signal of the
    Type: Grant
    Filed: November 30, 2020
    Date of Patent: August 10, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Sho Ikeda, Akihito Hirai, Koji Tsutsumi, Mitsuhiro Shimozawa
  • Publication number: 20210211134
    Abstract: A lock detection circuit is configured to include an integrating circuit that integrates a phase difference between a frequency-divided signal of a VCO and a reference signal during a constant period within a transient response period for an output signal from the VCO, and integrates a phase difference between the frequency-divided signal and the reference signal during a constant period within a convergence period for the output signal from the VCO; and a degree-of-convergence calculating circuit that calculates a degree at which the output signal from the VCO has converged, from a result of the integration of the phase difference obtained by the integrating circuit during the constant period within the transient response period and a result of the integration of the phase difference obtained by the integrating circuit during the constant period within the convergence period.
    Type: Application
    Filed: March 24, 2021
    Publication date: July 8, 2021
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Koji TSUTSUMI, Sho IKEDA
  • Patent number: 11043955
    Abstract: A first pulse selector outputs an output signal of a variable frequency divider to phase frequency detectors in a time division manner. A second pulse selector outputs a reference signal from a reference signal source to the phase frequency detectors in a time division manner. Outputs of the phase frequency detectors are provided, respectively, for multiple disposed charge pump circuits.
    Type: Grant
    Filed: July 24, 2020
    Date of Patent: June 22, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Koji Tsutsumi, Sho Ikeda, Mitsuhiro Shimozawa
  • Patent number: 11005429
    Abstract: A first transistor, a second transistor, a third transistor, and a fourth transistor, their source terminals being grounded, are provided. Further, a first feedback circuit connected between a gate terminal and a drain terminal in the first transistor, and having first impedance, a second feedback circuit connected between a gate terminal and a drain terminal in the second transistor, and having the first impedance, a current source for outputting a current, a first load circuit connected between the drain terminal of the first transistor and a first output terminal of the current source, and having second impedance, and a second load circuit connected between the drain terminal of the second transistor and a second output terminal of the current source, and having the second impedance are provided.
    Type: Grant
    Filed: March 23, 2017
    Date of Patent: May 11, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Takaya Maruyama, Koji Tsutsumi
  • Publication number: 20210109193
    Abstract: A radar device includes a transmission module, a reception module, and a signal processing unit. The transmission module includes an RF signal source that generates a transmission chirp signal synchronized with a reference signal. The reception module includes an RF signal source that generates a reception chirp signal used as a reception local signal and synchronized with the reference signal. The reception module receives a reflected wave of the transmission chirp signal emitted from the transmission module, and mixes a received reception signal with the reception chirp signal. The signal processing unit detects a target based on a beat signal generated by the mixing by the reception module.
    Type: Application
    Filed: December 1, 2020
    Publication date: April 15, 2021
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Koji TSUTSUMI, Tatsuya HAGIWARA, Mitsuhiro SHIMOZAWA
  • Publication number: 20210099144
    Abstract: A variable gain amplifier includes a first transistor group which is connected to an input terminal and an output terminal, and which amplifies a signal from the input terminal to output the amplified signal to the output terminal; a second transistor group connected to the input terminal; a third transistor group connected to the output terminal; and a controller configured to control the first transistor group, the second transistor group, and the third transistor group so that a total number of the number of transistors to be turned on in the first transistor group and the second transistor group is kept at a constant value, and total numbers of transistors to be turned on in the first transistor group and in the third transistor group are the same.
    Type: Application
    Filed: December 15, 2020
    Publication date: April 1, 2021
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Wataru YAMAMOTO, Koji TSUTSUMI, Mitsuhiro SHIMOZAWA
  • Publication number: 20210083681
    Abstract: A phase-locked loop circuit includes: a division ratio control circuit controlling a division ratio of an output signal of a variable frequency divider on the basis of an addition signal of a negative feedback signal and a division ratio setting signal indicating the division ratio, in synchronization with a divided signal output from the variable frequency divider; a first phase detection circuit calculating a first phase detection signal indicating a phase of an output signal of a signal output circuit; a second phase detection circuit calculating a second phase detection signal indicating a phase of the output signal of a case where it is assumed that the division ratio control circuit controls the division ratio of the output signal of the variable frequency divider in synchronization with the reference signal; and a shift circuit generating a negative feedback signal from a difference between the first phase detection signal and the second phase detection signal, and outputting an addition signal of the
    Type: Application
    Filed: November 30, 2020
    Publication date: March 18, 2021
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Sho IKEDA, Akihito HIRAI, Koji TSUTSUMI, Mitsuhiro SHIMOZAWA