Patents by Inventor Brett Walker

Brett Walker 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).

  • Publication number: 20070049212
    Abstract: In one embodiment, this disclosure describes a frequency synthesizer for use in a wireless communication device, or similar device that requires precision frequency synthesis but small amounts of noise. In particular, the frequency synthesizer may include a phase locked loop (PLL) and an integrated voltage controlled oscillator (VCO). The frequency synthesizer may implement one or more amplitude calibration techniques prior to enabling the PLL. For example, an amplitude calibration unit may be used to selectively activate switched unit current sources within a tail current source of the VCO. In this manner, the amplitude the signal generated by the oscillator can be adjusted without requiring closed-loop amplitude monitoring or control.
    Type: Application
    Filed: May 18, 2006
    Publication date: March 1, 2007
    Inventors: Jeremy Dunworth, Brett Walker
  • Publication number: 20060038617
    Abstract: A radio frequency (RF) driver amplifier system and method that provides linear in decibel gain control is provided. The RF driver amplifier system comprises a linear transconductor receiving an input voltage and providing a controlled current based on input voltage received, temperature compensation circuitry for varying current from the linear transconductor according to absolute temperature, an exponential current controller receiving current varied according to temperature and providing an exponential current in response, and an inductive degeneration compensator receiving exponential current and providing a control current to driver amplifier circuitry, thereby compensating for inductive degeneration due to at least one inductor in the driver amplifier circuitry. Control current passes from the inductive degeneration compensator to the driver amplifier circuitry. Output gain from the driver amplifier circuitry varies linearly in decibels with respect to the input voltage.
    Type: Application
    Filed: June 13, 2005
    Publication date: February 23, 2006
    Inventors: Kenneth Barnett, Brett Walker, Kevin Gard
  • Publication number: 20050259609
    Abstract: Embodiments disclosed herein address the need for a single wire bus interface. In one aspect, a device communicates with a second device via a single wire bus using a driver for driving the bus with a write frame comprising a start symbol, a write indicator symbol, an address, and data symbols. In another aspect, the device receives one or more data symbols on the single wire bus during a read frame. In yet another aspect, a device communicates with a second device via a single wire bus using a receiver for receiving a frame on the single wire bus comprising a start symbol, a write indicator symbol, an address, and one or more data symbols, and a driver for driving return read data associated with the address when the write indicator identifies a write frame. Various other aspects are also presented. These aspects provide for communication on a single wire bus, which allows for a reduction in pins, pads, or inter-block connections between devices.
    Type: Application
    Filed: May 20, 2004
    Publication date: November 24, 2005
    Inventors: David Hansquine, Brett Walker, Muhammad Muneer
  • Publication number: 20050208919
    Abstract: A direct downconversion receiver architecture having a DC loop to remove DC offset from the signal components, a digital variable gain amplifier (DVGA) to provide a range of gains, an automatic gain control (AGC) loop to provide gain control for the DVGA and RF/analog circuitry, and a serial bus interface (SBI) unit to provide controls for the RF/analog circuitry via a serial bus. The DVGA may be advantageously designed and located as described herein. The operating mode of the VGA loop may be selected based on the operating mode of the DC loop, since these two loops interact with one another. The duration of time the DC loop is operated in an acquisition mode may be selected to be inversely proportional to the DC loop bandwidth in the acquisition mode. The controls for some or all of the RF/analog circuitry may be provided via the serial bus.
    Type: Application
    Filed: May 16, 2005
    Publication date: September 22, 2005
    Inventors: Brett Walker, Paul Peterzell, Tao Li, Matthew Severson
  • Publication number: 20020107907
    Abstract: The present invention provides a system and method for remotely accessing a client in a client-server system. From a browser, an end user enters a URL containing a machine name and a port number. A listening program at the client listening on that port number establishes communication with the browser and invokes a client agent. The client agent includes conventional client functions as well as APIs that allow the client to interface with both the server and the browser. The client agent then serves an applet to the browser that makes the browser appear to the end user as the client machine. The user can then execute client functions from the browser. Examples of the client functions include backing up and restoring files from the client to/from the server, migrating or recalling files, archiving or retrieving files.
    Type: Application
    Filed: November 12, 1998
    Publication date: August 8, 2002
    Inventors: DOUGLAS ROBERT CASE, DAVID DERK, JAMES MICHAEL DILE, ROBERT CLAIR EDWARDS, AVISHAI HAIM HOCHBERG, DAVID T. KWAN, THOMAS FRANKLIN RAMKE, PETE TANENHAUS, RANDY TUNG, JOHN VIKSNE, BRETT WALKER, HUI-LAN WEN