Patents by Inventor Keming Joseph Chen

Keming Joseph Chen 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: 7395037
    Abstract: A method and system for controlling an output signal power level of a wireless transmitter can be created by detecting the signal power level of the transmitter with a detector, selectively attenuating the output signal power level with an attenuator having variable attenuation levels, and monitoring the output signal power level and comparing the output signal power level, as determined by the detector, to a predetermined threshold with a processor. The processor preferably controls the attenuator in accordance with the comparison of the output signal power level and the predetermined threshold.
    Type: Grant
    Filed: February 9, 2007
    Date of Patent: July 1, 2008
    Assignee: General Instrument Corporation
    Inventor: Keming Joseph Chen
  • Patent number: 7177606
    Abstract: A method and system for controlling an output signal power level of a wireless transmitter can be created by detecting the signal power level of the transmitter with a detector, selectively attenuating the output signal power level with an attenuator having variable attenuation levels, and monitoring the output signal power level and comparing the output signal power level, as determined by the detector, to a predetermined threshold with a processor. The processor preferably controls the attenuator in accordance with the comparison of the output signal power level and the predetermined threshold.
    Type: Grant
    Filed: July 10, 2002
    Date of Patent: February 13, 2007
    Assignee: General Instrument Corporation
    Inventor: Keming Joseph Chen
  • Patent number: 7167528
    Abstract: A method and system for modulating data onto a carrier signal in a plurality of channels, each of the channels having a channel bandwidth, can be created for use in any two-way satellite communication system or other wireless communication application where frequency hopping with or without Doppler compensation is desired. The system preferably includes a digital modulator that outputs a modulated baseband signal, an intermediate frequency modulator that receives the modulated baseband signal and outputs an intermediate frequency signal derived from the modulated baseband signal, a frequency synthesizing system that outputs a synthesized intermediate frequency signal to the intermediate frequency modulator, and a circuit (numerically controlled oscillator) connected to the digital modulator which provides a signal to the digital modulator.
    Type: Grant
    Filed: June 11, 2002
    Date of Patent: January 23, 2007
    Assignee: General Instrument Corporation
    Inventors: Keming Joseph Chen, Mark Steven Schmidt
  • Publication number: 20040092237
    Abstract: A method and system for controlling an output signal power level of a wireless transmitter can be created by detecting the signal power level of the transmitter with a detector, selectively attenuating the output signal power level with an attenuator having variable attenuation levels, and monitoring the output signal power level and comparing the output signal power level, as determined by the detector, to a predetermined threshold with a processor. The processor preferably controls the attenuator in accordance with the comparison of the output signal power level and the predetermined threshold.
    Type: Application
    Filed: July 10, 2002
    Publication date: May 13, 2004
    Inventor: Keming Joseph Chen
  • Publication number: 20030227982
    Abstract: A method and system for modulating data onto a carrier signal in a plurality of channels, each of the channels having a channel bandwidth, can be created for use in any two-way satellite communication system or other wireless communication application where frequency hopping with or without Doppler compensation is desired. The system preferably includes a digital modulator that outputs a modulated baseband signal, an intermediate frequency modulator that receives the modulated baseband signal and outputs an intermediate frequency signal derived from the modulated baseband signal, a frequency synthesizing system that outputs a synthesized intermediate frequency signal to the intermediate frequency modulator, and a circuit (numerically controlled oscillator) connected to the digital modulator which provides a signal to the digital modulator.
    Type: Application
    Filed: June 11, 2002
    Publication date: December 11, 2003
    Inventors: Keming Joseph Chen, Mark Steven Schmidt
  • Patent number: 6108046
    Abstract: A method and apparatus for automatically detecting the format of a high-definition television (HDTV) signal at a video encoder to allow proper encoding of the signal, including progressive and interlaced scan, and specific pixel and vertical line resolutions. The system is compatible with video standards such as the SMPTE and MPEG-2 standards. A video sample clock is determined by phase-locking clock pulses in a video signal to one of two or more available reference clocks. An SAV/EAV counter and pixel sample counter determine the horizontal resolution of the video, e.g., pixels per line. The system discriminates between 24 frames per second video and 30 frames per second video, and between a 720 line progressive scan signal and a 1080 line interlaced scan signal, for example. The system uses PLLs for each reference clock, where a lock range of the PLLs is narrow such that two PLLs will not lock at the same time for one input frequency.
    Type: Grant
    Filed: June 1, 1998
    Date of Patent: August 22, 2000
    Assignee: General Instrument Corporation
    Inventors: Siu-Wai Wu, Keming Joseph Chen, Erik Elstermann
  • Patent number: 5784413
    Abstract: A frequency-agile, direct digital synthesis (DDS) modulator includes a double conversion architecture which provides an output signal having a good output spectrum with low spurious signals. The modulator is particularly suitable for providing a quadrature phase-shift keyed (QPSK) data signal. The modulator includes a direct digital synthesizer (DDS) for generating a data signal in response to a clock signal operating at an associated clock frequency. Two local oscillators are provided for respectively up-converting and then down-converting the DDS data signal to provide the output signal having the desired spectral characteristics. The first local oscillator operates at a first mixing frequency, while the second local oscillator is responsive to the clock signal for providing a second mixing signal at the clock frequency. This configuration eliminates the need for a phase lock loop for the second oscillator.
    Type: Grant
    Filed: September 6, 1996
    Date of Patent: July 21, 1998
    Assignee: General Instrument Corporation
    Inventor: Keming Joseph Chen