Patents Assigned to IRF Semiconductor, Inc.
  • Patent number: 7015736
    Abstract: A charge pump is disclosed which generates higher and more symmetric source and sink currents that prior designs and reduces the multiple frequency sidebands that occur in a voltage controlled oscillator of a phase-loop synthesizer. Other improvements are the reduction in reference frequency feed-through, charge sharing and noise transient coupling and phase noise in the phase-locked loop. Possible applications include but are not limited to charge pump phase-locked designs for single chip CMOS multi-band and multi-standard radio frequency integrated circuits.
    Type: Grant
    Filed: July 13, 2004
    Date of Patent: March 21, 2006
    Assignee: IRF Semiconductor, Inc.
    Inventors: Douglas Sudjian, David H. Shen
  • Patent number: 7015768
    Abstract: A low-phase-noise and high-performance voltage-controlled oscillator (VCO) uses a noise-canceling differential varactor topology. An implementation includes circuitry for a fully-differential varactor-inductor oscillator for reduced noise and improved performance. Susceptibility to common-mode noise sources coupled into the varactors is reduced.
    Type: Grant
    Filed: August 27, 2004
    Date of Patent: March 21, 2006
    Assignee: IRF Semiconductor, Inc.
    Inventor: Niranjan Talwalkar
  • Publication number: 20040227594
    Abstract: A method for tuning a high quality resonant circuit based on bonding wire inductors and tunable capacitors is disclosed which permits greater integration on standard silicon chips and greater insensitivity to manufacturing and ambient temperature variations. The L-C resonant circuit is tuned by a phase-locked loop with an L-C based VCO. Bonding wire inductors can be used in the resonant circuit in order to enhance the quality factor, and manufacturing variations of the bonding wire inductors are compensated by the tuning circuit. The L-C resonant circuit can be operated continuously with the tuning circuit turned off.
    Type: Application
    Filed: December 5, 2003
    Publication date: November 18, 2004
    Applicant: IRF SEMICONDUCTOR, INC.
    Inventor: David H. Shen
  • Publication number: 20040121751
    Abstract: A subharmonic mixer design is described that permits greater integration on standard silicon chips with an improvement in power and linearity compared to previous mixer designs, enabling low-power, high performance RF reception.
    Type: Application
    Filed: December 5, 2003
    Publication date: June 24, 2004
    Applicant: IRF SEMICONDUCTOR, INC.
    Inventor: David H. Shen
  • Publication number: 20040116087
    Abstract: A RF communications receiver is disclosed which permits greater integration on standard silicon chips and consumes less power than previous receivers. A new method for using a tracking intermediate frequency filter for a variable intermediate frequency receiver ensures good performance over an entire received frequency band.
    Type: Application
    Filed: December 5, 2003
    Publication date: June 17, 2004
    Applicant: IRF SEMICONDUCTOR, INC.
    Inventor: David H. Shen
  • Publication number: 20040113705
    Abstract: A method for tuning an on-chip L-C filter is disclosed which permits greater integration on standard silicon chips and greater insensitivity to manufacturing and ambient temperature variations. The L-C filter is tuned by a phase-locked loop with a L-C based VCO. The tuning loop can be powered down to save power and reduce noise coupling. The L-C filter can be operated continuously.
    Type: Application
    Filed: December 5, 2003
    Publication date: June 17, 2004
    Applicant: IRF SEMICONDUCTOR, INC.
    Inventor: David H. Shen
  • Publication number: 20040113724
    Abstract: A high quality resonant circuit that can easily be integrated into an integrated circuit package or substrate is disclosed. The resonant circuit is based on a transmission line impedance transformation property, which allows the resonant circuit to have higher quality factor than existing integrated L-C implementations.
    Type: Application
    Filed: December 5, 2003
    Publication date: June 17, 2004
    Applicant: IRF SEMICONDUCTOR, INC.
    Inventor: David H. Shen
  • Publication number: 20040116096
    Abstract: A RF communications receiver is disclosed which permits greater integration on standard silicon chips and consumes less power than previous receivers. A new method for using a tracking polyphase filter for image rejection of variable intermediate frequencies is introduced. This method allows for reduce sensitivity to resistor and capacitor manufacturing variations and allows for the polyphase filter response to be enhanced compared to the prior art.
    Type: Application
    Filed: December 5, 2003
    Publication date: June 17, 2004
    Applicant: IRF SEMICONDUCTOR, INC.
    Inventor: David H. Shen
  • Publication number: 20040116095
    Abstract: The high dynamic range mixer is disclosed which enables wideband frequency translation of radio frequency signals and particularly suited for radio with zero-IF or low-IF receiver architectures, as the dynamic range requirements on the mixers in these radios are particularly severe.
    Type: Application
    Filed: December 5, 2003
    Publication date: June 17, 2004
    Applicant: IRF SEMICONDUCTOR, INC.
    Inventor: David H. Shen
  • Publication number: 20040116097
    Abstract: A multiple frequency RF communications receiver is disclosed which permits greater integration on standard silicon chips and consumes less power than previous receivers. A new method for selecting the various frequency bands with a high amount of isolation and low power consumption is described. Compared to previous receiver implementations, there is no loss of selectivity in the receiver.
    Type: Application
    Filed: December 5, 2003
    Publication date: June 17, 2004
    Applicant: IRF SEMICONDUCTOR, INC.
    Inventor: David H. Shen