Patents Examined by Tuyen Vu
  • Patent number: 5606735
    Abstract: A device and method for correcting an amplitude slope in the frequency domain of an input signal. An amplitude slope is detected in parallel feedback loops that connect the combined output of two parallel out-of-band notch filters through a slope detection circuit to inputs of each of the two notch filters. Each feedback loop detects the energy at one of the high and low frequencies that define the frequency domain of the input signal, and provides a voltage indicative of the energy back to the notch filters to vary the Q of the notch filters, thereby correcting the amplitude slope. The energy is detected in each feedback loop by mixing the input signal with one of the high and low frequencies that define the frequency domain of the input signal, and filtering out all but the DC voltage indicative of the energy at the one frequency. The DC voltage changes the resistance of an element in the notch filters to vary Q.
    Type: Grant
    Filed: June 29, 1995
    Date of Patent: February 25, 1997
    Assignee: Harris Corporation
    Inventor: Nick Ierfino