Patents Assigned to Sharp KK Corporation
  • Patent number: 6154503
    Abstract: An automatic gain control (AGC) system that monitors the distortion of the outer constellation points of a complex modulation format such as quadrature amplitude modulation (QAM) and adjusts both the RF and IF AGC gain to minimize such distortion. In particular, the receiver contains at least two stages of AGC gain. Typically, the RF AGC amplifier is contained in the tuner that is followed by an IF AGC amplifier. The IF amplifier is coupled to a mixer and an associated low pass filter which, in combination and when driven by a particular frequency, produces a baseband (or near baseband) signal, The baseband signal is digitized and processed by a gain control circuit. The gain control circuit produces IF and RF AGC signals that control the gain of the respective AGC stages.
    Type: Grant
    Filed: June 5, 1997
    Date of Patent: November 28, 2000
    Assignees: Sharp KK Corporation, Sarnoff Corporation
    Inventor: Christopher Hugh Strolle