Patents by Inventor Naoki Takachi

Naoki Takachi 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: 6791409
    Abstract: (Object) It was difficult for a feedforward amplifier to perform stable and high-speed distortion compensation control. (Constitution) It is a feedforward amplifier having CPL1 of dividing an input carrier signal into two output signals, VAP1 of adjusting one of the two divided output signals, AMP1 of amplifying the adjusted one of the output signals to generate an amplification signal, CPL2 of extracting a distortion signal by utilizing the other output signal of the two divided output signals and the generated amplification signal, CPL3 of generating an output carrier signal by utilizing the generated amplification signal and the extracted distortion signal, and CNT1 having a log amplifier of controlling VAP1 based on the other output signal and the generated amplification signal.
    Type: Grant
    Filed: July 18, 2002
    Date of Patent: September 14, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kaoru Ishida, Naoki Takachi, Rie Takeuchi
  • Patent number: 6750706
    Abstract: A method of controlling a feedforward distortion compensation amplifier has steps of detecting a distortion component generated in a main amplifier by coupling a signal branched from a signal input to the main amplifier and containing a plurality of carriers of different frequencies to a signal branched from an output signal from the main amplifier so that the coupling causes the carrier components to cancel each other, recoupling the signal resulting from the coupling to the output signal from the main amplifier, and adjusting an amplitude and phase of at least one of the signals to be recoupled so that distortion components cancel each other upon recoupling, wherein a first and second pilot signals obtained from a first and second pilot signal sources are inserted into the input signal to or output signal from the main amplifier, parts of the signal resulting from the recoupling are taken out through branching, and the signals taken out through branching are mixed with the first and second pilot signals
    Type: Grant
    Filed: June 11, 2002
    Date of Patent: June 15, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kaoru Ishida, Toshimitsu Matsuyoshi, Naoki Takachi, Yuji Saito
  • Patent number: 6734727
    Abstract: A feedforward amplifier includes a main amplifier for amplifying an input signal, a control circuit for generating a predetermined pilot signal based on the output of a local oscillator and a frequency divider included in the control circuit, and a coupler for combining the input signal or the amplified signal with the pilot signal to generate a combined signal. A first coupler and a second coupler are provided for extracting any distortion component from the combined signal. A vector adjuster, an error amplifier, and a third coupler are provided for removing the extracted distortion component from the combined signal to generate an output signal. An orthogonal detector is provided for using any one of the pilot signal, or the output of the local oscillator, the frequency divider, and the combination of the vector adjuster, error amplifier, and the third coupler to make an adjustment for removing the distortion component.
    Type: Grant
    Filed: August 21, 2002
    Date of Patent: May 11, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kaoru Ishida, Naoki Takachi, Yuji Saito
  • Publication number: 20030058042
    Abstract: A feedforward amplifier has
    Type: Application
    Filed: August 21, 2002
    Publication date: March 27, 2003
    Inventors: Kaoru Ishida, Naoki Takachi, Yuji Saito
  • Publication number: 20030020541
    Abstract: (Object)
    Type: Application
    Filed: July 18, 2002
    Publication date: January 30, 2003
    Inventors: Kaoru Ishida, Naoki Takachi, Rie Takeuchi
  • Publication number: 20030016081
    Abstract: A method of controlling a feedforward distortion compensation amplifier has steps of
    Type: Application
    Filed: June 11, 2002
    Publication date: January 23, 2003
    Inventors: Kaoru Ishida, Toshimitsu Matsuyoshi, Naoki Takachi, Yuji Saito