Patents by Inventor Derek K. Wong

Derek K. Wong 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).

  • Center frequency control of an integrated phase rotator band-pass filter using VCO coarse trim bits
    Patent number: 7421252
    Abstract: A phase rotator for a Cartesian feedback power amplifier in a transmitter final stage contains an integrated voltage controlled tunable resonant circuit accomplishing band-pass filtering at a center frequency selected by local oscillator (LO) coarse trim control signals. The voltage controlled tunable resonant circuit attenuates input signal harmonic levels at large fractional bandwidths for the downconverter in the feedback LO path without setting a large number of poles in the band-pass filter. The binary-weighted course trim value for controlling the gain of the LO sets a bank of voltage-variable capacitors (VVC) in the voltage controlled tunable resonant circuit to control the center frequency in each of two 2-pole band-pass filters, creating a composite 4-pole band-pass filter at the input of a poly-phase quadrature generation circuit in the feedback LO path.
    Type: Grant
    Filed: August 2, 2005
    Date of Patent: September 2, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Mark A. Kirschenmann, Derek K. Wong