Patents by Inventor Derek K. Shaeffer

Derek K. Shaeffer 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: 7248628
    Abstract: A system includes a sampling circuit, an analog filter, an analog input, a modulator, and a modulating source. The modulating source includes an output that generates an impulse response encoded as a sigma-delta sequence. The output of the modulating source is coupled to the modulator, which is coupled to the analog input. The analog filter is coupled to the modulator and the sampling circuit. When the system is configured as a filter, an analog signal is modulated with the sigma-delta sequence. The modulated signal is filtered and then sampled.
    Type: Grant
    Filed: March 2, 2001
    Date of Patent: July 24, 2007
    Inventor: Derek K. Shaeffer
  • Patent number: 7164313
    Abstract: Circuits, methods, and systems are provided for opening a primary feedback loop in a transmitter. An auxiliary feedback loop can be closed when the primary feedback loop is opened, and a controller can match a gain of the primary feedback loop to another gain in the transmitter.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: January 16, 2007
    Assignee: Aspendos Communications
    Inventors: Peter Capofreddi, Derek K. Shaeffer, Sriraman Dakshinamurthy, Korhan Titizer
  • Patent number: 7132885
    Abstract: A circuit is provided that includes a Cartesian feedback loop. The Cartesian feedback loop includes one or more operational amplifiers. At least one of the operational amplifiers includes two or more cascaded amplifier stages and one or more bypass amplifier stages. The bypass amplifier stages are connected in parallel with the cascaded amplifier stages.
    Type: Grant
    Filed: March 23, 2005
    Date of Patent: November 7, 2006
    Assignee: Aspendos Communications
    Inventors: Peter Capofreddi, Derek K. Shaeffer, Korhan Titizer
  • Publication number: 20040071244
    Abstract: A system includes a sampling circuit, an analog filter, an analog input, a modulator, and a modulating source. The modulating source includes an output that generates an impulse response encoded as a sigma-delta sequence. The output of the modulating source is coupled to the modulator, which is coupled to the analog input. The analog filter is coupled to the modulator and the sampling circuit. When the system is configured as a filter, an analog signal is modulated with the sigma-delta sequence. The modulated signal is filtered and then sampled.
    Type: Application
    Filed: March 2, 2001
    Publication date: April 15, 2004
    Inventor: Derek K. Shaeffer
  • Patent number: 6084285
    Abstract: Linear integrated circuit capacitors having greater capacitance per unit area by using lateral flux. One embodiment comprises a two metal layer capacitor wherein each metal layer is comprised of two capacitor conductive components. The capacitor conductive components are cross-coupled so that the total capacitance is the sum of the vertical flux between the metal layers, and the lateral flux along the edges between the two capacitor conductive components in each of the metal layers. The lateral flux between the capacitor conductive components in a single metal layer increases the capacitance per unit area and decreases the bottom-plate parasitic capacitance. Increasing the length of the common edge formed by capacitor conductive components in a metal layer increases the capacitance per unit area. In one lateral flux capacitor, each metal layer is comprised of a plurality of rows, alternate rows are coupled together such that lateral flux is generated between each of the rows.
    Type: Grant
    Filed: October 20, 1997
    Date of Patent: July 4, 2000
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Arvin R. Shahani, Thomas H. Lee, Hirad Samavati, Derek K. Shaeffer, Steven Walther
  • Patent number: 6028990
    Abstract: Linear integrated circuit capacitors having greater capacitance per unit area by using lateral flux. One embodiment comprises a two metal layer capacitor wherein each metal layer is comprised of two capacitor conductive components. The capacitor conductive components are cross-coupled so that the total capacitance is the sum of the vertical flux between the metal layers, and the lateral flux along the edges between the two capacitor conductive components in each of the metal layers. The lateral flux between the capacitor conductive components in a single metal layer increases the capacitance per unit area and decreases the bottom-plate parasitic capacitance. Increasing the length of the common edge formed by capacitor conductive components in a metal layer increases the capacitance per unit area. In one lateral flux capacitor, each metal layer is comprised of a plurality of rows, alternate rows are coupled together such that lateral flux is generated between each of the rows.
    Type: Grant
    Filed: December 28, 1998
    Date of Patent: February 22, 2000
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Arvin R. Shahani, Thomas H. Lee, Hirad Samavati, Derek K. Shaeffer, Steven Walther