Patents by Inventor Kazuaki Kunihiro

Kazuaki Kunihiro 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: 11158945
    Abstract: A phased array antenna apparatus 10 according to an example embodiment includes at least four patch antennas 6 arranged in a two-dimensional array, and a semiconductor IC 1 connected to the patch antennas 6, in which the semiconductor IC 1 includes at least two first input/output terminals 5 through which a transmission/reception signal is input/output between the phased array antenna apparatus and an external apparatus connected to the phased array antenna apparatus, a plurality of second input/output terminals 4 connected to feeding points 8 of the patch antennas 6 through respective feed lines 7, the plurality of second input/output terminals being terminals through which the transmission/reception signal is input/output, and a matrix switch 2 capable of changing a connection relation between the first input/output terminals 5 and the second input/output terminals 4.
    Type: Grant
    Filed: September 25, 2020
    Date of Patent: October 26, 2021
    Assignee: NEC CORPORATION
    Inventors: Korkut Tokgoz, Naoki Oshima, Kazuaki Kunihiro
  • Publication number: 20210098874
    Abstract: A phased array antenna apparatus 10 according to an example embodiment includes at least four patch antennas 6 arranged in a two-dimensional array, and a semiconductor IC 1 connected to the patch antennas 6, in which the semiconductor IC 1 includes at least two first input/output terminals 5 through which a transmission/reception signal is input/output between the phased array antenna apparatus and an external apparatus connected to the phased array antenna apparatus, a plurality of second input/output terminals 4 connected to feeding points 8 of the patch antennas 6 through respective feed lines 7, the plurality of second input/output terminals being terminals through which the transmission/reception signal is input/output, and a matrix switch 2 capable of changing a connection relation between the first input/output terminals 5 and the second input/output terminals 4.
    Type: Application
    Filed: September 25, 2020
    Publication date: April 1, 2021
    Applicant: NEC Corporation
    Inventors: Korkut TOKGOZ, Naoki OSHIMA, Kazuaki KUNIHIRO
  • Patent number: 9838068
    Abstract: A transmitter/receiver apparatus including: a transmitter/receiver terminal; a switching amplifier that includes a low-side switching element connected between a ground terminal and a pulse output terminal and a high-side switching element connected between the pulse output terminal and a power supply terminal and that outputs a pulse signal from the pulse output terminal; a filter that passes therethrough and outputs as a transmitted signal a predetermined frequency component of the pulse signal from a transmitter terminal; and a transmit/receive switch unit that switches the connection status between the transmitter/receiver terminal and the transmitter terminal and also switches the connection status between the transmitter/receiver terminal and a receiver terminal.
    Type: Grant
    Filed: October 15, 2014
    Date of Patent: December 5, 2017
    Assignee: NEC CORPORATION
    Inventors: Kazuaki Kunihiro, Shinichi Hori
  • Patent number: 9531327
    Abstract: When frequency allocation for a plurality of frequencies is in an intra-band CA relationship, a first amplifier is operated in class B, a second amplifier is operated in class C, and a power modulator is caused to supply a constant voltage to the first and second amplifiers so as to operate as a Doherty-type power amplifier. In addition, when the frequency allocation for the plurality of frequencies is in an inter-band non-contiguous CA relationship, the first and second amplifiers are operated in class B, and the power modulator is caused to supply a voltage proportional to the amplitude component of an input signal to the first and second amplifiers so as to operate as a power amplifier based on an ET system.
    Type: Grant
    Filed: October 29, 2013
    Date of Patent: December 27, 2016
    Assignee: NEC CORPORATION
    Inventor: Kazuaki Kunihiro
  • Publication number: 20160248470
    Abstract: A transmitter/receiver apparatus including: a transmitter/receiver terminal; a switching amplifier that includes a low-side switching element connected between a ground terminal and a pulse output terminal and a high-side switching element connected between the pulse output terminal and a power supply terminal and that outputs a pulse signal from the pulse output terminal; a filter that passes therethrough and outputs as a transmitted signal a predetermined frequency component of the pulse signal from a transmitter terminal; and a transmit/receive switch unit that switches the connection status between the transmitter/receiver terminal and the transmitter terminal and also switches the connection status between the transmitter/receiver terminal and a receiver terminal.
    Type: Application
    Filed: October 15, 2014
    Publication date: August 25, 2016
    Applicant: NEC CORPORATION
    Inventors: Kazuaki KUNIHIRO, Shinichi HORI
  • Patent number: 9236838
    Abstract: An object of the present invention is to provide a power amplification device having high power efficiency for an input signal even in a power region in a large back-off. A power amplification device of the present invention includes a delta-sigma modulator which performs a multilevel delta sigma modulation on amplitude signals of input signals, a plurality of power amplifiers which amplify carrier signals, an encoder which generates a first control signal that controls ON/OFF of the outputs from said plurality of power amplifiers in accordance with the output from said delta-sigma modulator, and a combiner which combines at least two power output from said plurality of power amplifiers in accordance with said first control signal.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: January 12, 2016
    Assignee: NEC CORPORATION
    Inventor: Kazuaki Kunihiro
  • Publication number: 20150263768
    Abstract: A transmitter includes: multiple digital transmitters which perform delta-sigma modulation on the same baseband signal; a combiner that combines the output signals from the plural digital transmitters and outputs the combined result; a control unit that generates an external signal different for every digital transmitter, to be supplied to each of the digital transmitters; and, an input means that supplies the different external signal for every digital transmitter, to the input terminal or the internal node of a delta-sigma modulator that performs the delta-sigma modulation, the delta-sigma modulator being provided for every digital transmitter.
    Type: Application
    Filed: September 17, 2013
    Publication date: September 17, 2015
    Applicant: NEC CORPORATION
    Inventors: Shinichi Hori, Kazuaki Kunihiro, Kazumi Shiikuma
  • Publication number: 20150263678
    Abstract: When frequency allocation for a plurality of frequencies is in an intra-band CA relationship, a first amplifier is operated in class B, a second amplifier is operated in class C, and a power modulator is caused to supply a constant voltage to the first and second amplifiers so as to operate as a Doherty-type power amplifier. In addition, when the frequency allocation for the plurality of frequencies is in an inter-band non-contiguous CA relationship, the first and second amplifiers are operated in class B, and the power modulator is caused to supply a voltage proportional to the amplitude component of an input signal to the first and second amplifiers so as to operate as a power amplifier based on an ET system.
    Type: Application
    Filed: October 29, 2013
    Publication date: September 17, 2015
    Applicant: NEC CORPORATION
    Inventor: Kazuaki Kunihiro
  • Patent number: 8902001
    Abstract: Provided are a highly efficient, low waveform distortion power supply device and a power amplifying apparatus with high efficiency and high linearity using the device as a power supply. A power supply device of the present invention comprises a linear amplifier unit 400 which linearly amplifies an input signal and outputs it as an electric current Ic, and a switching amplification control unit 500, which outputs an electric current Im using a plurality of switching amplifying units 601, 602, . . . 60n for outputting respective predetermined voltages on the basis of the magnitude of the electric current Ic outputted from said linear amplifier unit 400; and it generates an output voltage Vout according to the waveform of the input signal, and outputs an electric current Iout which is a combination of the electric currents Ic and Im.
    Type: Grant
    Filed: May 13, 2011
    Date of Patent: December 2, 2014
    Assignee: NEC Corporation
    Inventors: Kazuaki Kunihiro, Yasushi Watanabe
  • Publication number: 20140218104
    Abstract: An object of the present invention is to provide a power amplification device having high power efficiency for an input signal even in a power region in a large back-off. A power amplification device of the present invention includes a delta-sigma modulator which performs a multilevel delta sigma modulation on amplitude signals of input signals, a plurality of power amplifiers which amplify carrier signals, an encoder which generates a first control signal that controls ON/OFF of the outputs from said plurality of power amplifiers in accordance with the output from said delta-sigma modulator, and a combiner which combines at least two power output from said plurality of power amplifiers in accordance with said first control signal.
    Type: Application
    Filed: September 13, 2012
    Publication date: August 7, 2014
    Applicant: NEC CORPORATION
    Inventor: Kazuaki Kunihiro
  • Patent number: 8693578
    Abstract: A transmission device includes a pulse modulated signal generator that generates a pulse-modulated signal by changing the width of a pulse or the density of a pulse according to the magnitude of the amplitude component of an input signal while discretely changing the pulse height according to the magnitude of the amplitude, a modulated-signal generator that generates a modulated signal by integrating the pulse-modulated signal and the phase component of the input signal, a power amplifier that includes at least as many amplifiers as the number of the discrete amplitude levels of the modulated signal, changes the number of amplifies that amplify the modulated signal on the basis of the value of the amplitude level of the modulated signal, combines outputs of the amplifiers, and outputs a combined output, and an output filter that eliminates a square-wave component from the output of the power amplifier.
    Type: Grant
    Filed: December 1, 2010
    Date of Patent: April 8, 2014
    Assignee: NEC Corporation
    Inventors: Kazuaki Kunihiro, Shinichi Hori, Kazumi Shiikuma
  • Patent number: 8670731
    Abstract: Disclosed is a power amplifier apparatus including: an amplifier amplifying an input modulated signal; a control signal generator receiving an amplitude component of the input modulated signal and generating a control signal; and a power combiner performing ON/OFF control of a switching element based on the control signal to control conduction and non-conduction of a current supplied from a second power supply. In the power combiner, a power of a pulsed form when the current from the second power supply is conductive is transferred in a direction of a first power supply, using a transformer. A difference power obtained by subtracting a constant value from a first power supply voltage when the amplitude of the input modulated signal is smaller than that of a reference signal is supplied from the power combiner to the amplifier, as a power supply thereof (FIG. 1).
    Type: Grant
    Filed: June 25, 2009
    Date of Patent: March 11, 2014
    Assignee: NEC Corporation
    Inventor: Kazuaki Kunihiro
  • Patent number: 8620240
    Abstract: An aspect of a power amplifier according to the present invention is a power amplifier that amplifies a modulated signal including amplitude modulated components and phase modulated components, the power amplifier including a first voltage source 21 that amplifies low-frequency components of the amplitude modulated components of the modulated signal to output a first voltage VC_L, a second voltage source 22 that amplifies high-frequency components of the amplitude modulated components of the modulated signal to output a second voltage VC_H, a current source 24 that amplifies amplitude components of the modulated signal to output a current, a combiner circuit 23 that combines the first voltage VC_L, the second voltage VC_H, and a current IM to generate a modulated power supply signal VOUT, and an RF amplifier 30 that amplifies a signal obtained by up-converting the modulated signal to a carrier frequency and outputs the amplified signal after modulating amplitude of the amplified signal by the modulated power
    Type: Grant
    Filed: January 27, 2010
    Date of Patent: December 31, 2013
    Assignee: NEC Corporation
    Inventors: Shingo Yamanouchi, Kazuaki Kunihiro, Kazumi Shiikuma
  • Publication number: 20130342185
    Abstract: In order to improve power efficiency, a power supplying apparatus includes a switching amplification unit supplying a first load with most of electric power, and a linear amplification unit correcting an output voltage applied to the first load according to an input signal. Furthermore, an electric current which flows into the linear amplification unit at the time of the correcting is supplied to a second load from a power supply terminal of the linear amplification unit.
    Type: Application
    Filed: February 28, 2012
    Publication date: December 26, 2013
    Applicant: NEC CORPORATION
    Inventors: Kazuaki Kunihiro, Shinichi Hori, Masaaki Tanio
  • Patent number: 8594589
    Abstract: This invention provides a power amplifier (100) including a signal source control unit (110) which generates and outputs an amplitude signal serving as the amplitude modulated component of an input signal and a pulse modulated signal based on the amplitude signal, and outputs a transmission signal obtained by superposing the input signal on a carrier, a delay adjustment unit (120) which synchronizes the amplitude signal, pulse modulated signal, and transmission signal with each other, a voltage signal generation unit (130) which outputs a voltage signal corresponding to the amplitude signal synchronized with the transmission signal, a current signal generation unit (140) which outputs a current signal corresponding to the pulse modulated signal synchronized with the transmission signal, and a transmission signal amplification unit (150) which amplifies the transmission signal, and outputs a transmission signal obtained by modulating the amplitude of the amplified transmission signal based on a modulated power
    Type: Grant
    Filed: April 23, 2010
    Date of Patent: November 26, 2013
    Assignee: NEC Corporation
    Inventors: Shingo Yamanouchi, Kazuaki Kunihiro
  • Patent number: 8451054
    Abstract: A radio frequency amplifier amplifies a modulation signal or its phase modulation component and outputs the resultant signal. A linear amplifier adds an output voltage to a power supply voltage supplied to the radio frequency amplifier, amplifies a difference between the output voltage and the amplitude modulation component, and outputs the resultant difference. A control signal generation section detects a direction in which an output current of the linear amplifying section flows and generates a pulse modulation signal according to the direction of the current. A switching amplifying section controls connection and disconnection of a DC current based on the pulse modulation signal as a control signal so as to perform switching amplification for an output signal of the linear amplifying section, add the resultant signal to a predetermined DC voltage, and supply the resultant signal as the power supply voltage to the radio frequency amplifier.
    Type: Grant
    Filed: December 16, 2009
    Date of Patent: May 28, 2013
    Assignee: NEC Corporation
    Inventors: Kazuaki Kunihiro, Shingo Yamanouchi, Kazumi Shiikuma
  • Publication number: 20130057340
    Abstract: Provided are a highly efficient, low waveform distortion power supply device and a power amplifying apparatus with high efficiency and high linearity using the device as a power supply. A power supply device of the present invention comprises a linear amplifier unit 400 which linearly amplifies an input signal and outputs it as an electric current Ic, and a switching amplification control unit 500, which outputs an electric current Im using a plurality of switching amplifying units 601, 602, . . . 60n for outputting respective predetermined voltages on the basis of the magnitude of the electric current Ic outputted from said linear amplifier unit 400; and it generates an output voltage Vout according to the waveform of the input signal, and outputs an electric current Tout which is a combination of the electric currents Ic and Im.
    Type: Application
    Filed: May 13, 2011
    Publication date: March 7, 2013
    Applicant: NEC CORPORATION
    Inventors: Kazuaki Kunihiro, Yasushi Watanabe
  • Publication number: 20130016795
    Abstract: A transmission device includes a pulse modulated signal generator that generates a pulse-modulated signal by changing the width of a pulse or the density of a pulse according to the magnitude of the amplitude component of an input signal while discretely changing the pulse height according to the magnitude of the amplitude, a modulated-signal generator that generates a modulated signal by integrating the pulse-modulated signal and the phase component of the input signal, a power amplifier that includes at least as many amplifiers as the number of the discrete amplitude levels of the modulated signal, changes the number of amplifies that amplify the modulated signal on the basis of the value of the amplitude level of the modulated signal, combines outputs of the amplifiers, and outputs a combined output, and an output filter that eliminates a square-wave component from the output of the power amplifier.
    Type: Application
    Filed: December 1, 2010
    Publication date: January 17, 2013
    Applicant: NEC CORPORATION
    Inventors: Kazuaki Kunihiro, Shinichi Hori, Kazumi Shiikuma
  • Patent number: 8198950
    Abstract: A power amplifier that amplifies an RF modulation signal containing an amplitude modulation component and a phase modulation component, including a polar modulator that outputs an amplitude component signal that is the amplitude modulation component of the RF modulation signal, a direct current power supply that outputs a direct current voltage, a pulse modulator that pulse-modulates the amplitude component signal, a pulse amplification circuit that amplifies a pulse modulation signal, a combining circuit that adds a direct current voltage that is outputted from the direct current power supply to an output signal of the pulse amplification circuit, a low pass filter that smoothens an output signal of the combining circuit, and an RF amplifier that not only amplifies the RF modulation signal, but also amplitude-modulates the amplified signal with an output signal of the low pass filter and outputs the resultant signal.
    Type: Grant
    Filed: October 1, 2009
    Date of Patent: June 12, 2012
    Assignee: NEC Corporation
    Inventors: Shingo Yamanouchi, Kazuaki Kunihiro, Kazumi Shiikuma
  • Publication number: 20120126893
    Abstract: This invention provides a power amplifier (100) including a signal source control unit (110) which generates and outputs an amplitude signal serving as the amplitude modulated component of an input signal and a pulse modulated signal based on the amplitude signal, and outputs a transmission signal obtained by superposing the input signal on a carrier, a delay adjustment unit (120) which synchronizes the amplitude signal, pulse modulated signal, and transmission signal with each other, a voltage signal generation unit (130) which outputs a voltage signal corresponding to the amplitude signal synchronized with the transmission signal, a current signal generation unit (140) which outputs a current signal corresponding to the pulse modulated signal synchronized with the transmission signal, and a transmission signal amplification unit (150) which amplifies the transmission signal, and outputs a transmission signal obtained by modulating the amplitude of the amplified transmission signal based on a modulated power
    Type: Application
    Filed: April 23, 2010
    Publication date: May 24, 2012
    Inventors: Shingo Yamanouchi, Kazuaki Kunihiro