Patents by Inventor Wolf Zhang

Wolf Zhang 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).

  • Low distortion switching amplifier circuits and methods
    Patent number: 8111846
    Abstract: Embodiments of the present invention include switching amplifier circuits and methods. In one embodiment, the present invention includes a low distortion method of driving a switching amplifier comprising modulating an audio input signal to produce a half-wave rectified pulse-width modulated signal and a complementary half-wave rectified pulse-width modulated signal. These signals may be amplified in a power amplifier and combined in a feedback circuit to generate a first feedback signal and a second feedback signal, which may be coupled the inputs of a modulator for controlling the output signal.
    Type: Grant
    Filed: August 7, 2007
    Date of Patent: February 7, 2012
    Inventors: Hideto Takagishi, Wolf Zhang, Alan Wu
  • Low distortion switching amplifier circuits and methods
    Patent number: 7579910
    Abstract: Embodiments of the present invention include switching amplifier circuits and methods. In one embodiment, the present invention includes an low distortion method of driving a switching amplifier comprising generating a first pulse width modulated signal on a first terminal, generating a second pulse width modulated signal on a second terminal, and delaying one of the first or second signals. In one embodiment, the modulated signals and delay result in pulse trains near zero crossings to reduce crossover distortion.
    Type: Grant
    Filed: January 2, 2008
    Date of Patent: August 25, 2009
    Assignee: PacificTech Microelectronics, Inc.
    Inventors: Wolf Zhang, Hideto Takagishi, Alan Wu
  • Low Distortion Switching Amplifier Circuits and Methods
    Publication number: 20080174366
    Abstract: Embodiments of the present invention include switching amplifier circuits and methods. In one embodiment, the present invention includes an low distortion method of driving a switching amplifier comprising generating a first pulse width modulated signal on a first terminal, generating a second pulse width modulated signal on a second terminal, and delaying one of the first or second signals. In one embodiment, the modulated signals and delay result in pulse trains near zero crossings to reduce crossover distortion.
    Type: Application
    Filed: January 2, 2008
    Publication date: July 24, 2008
    Applicant: Pacific Tech Microelectronics, Inc.
    Inventors: Wolf Zhang, Hideto Takagishi, Alan Wu
  • Low distortion switching amplifier circuits and methods
    Publication number: 20080161953
    Abstract: Embodiments of the present invention include switching amplifier circuits and methods. In one embodiment, the present invention includes a low distortion method of driving a switching amplifier comprising modulating an audio input signal to produce a half-wave rectified pulse-width modulated signal and a complementary half-wave rectified pulse-width modulated signal. These signals may be amplified in a power amplifier and combined in a feedback circuit to generate a first feedback signal and a second feedback signal, which may be coupled the inputs of a modulator for controlling the output signal.
    Type: Application
    Filed: August 7, 2007
    Publication date: July 3, 2008
    Applicant: PacificTech Microelectronics, Incorporated
    Inventors: Hideto Takagishi, Wolf Zhang, Alan Wu