Patents by Inventor David N. Carson

David N. Carson 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: 4542534
    Abstract: A single-sideband FM receiver comprises an input (RF) stage (13), a mixer (14), a local oscillator (15) an intermediate frequency (IF) amplifier (16), and an FM detector (18). An oscillator (17) is phase and frequency locked to the IF frequency. The output of this phase-locked oscillator is coupled to the FM detector via a bandpass filter (20) and an amplitude control circuit (19), which controls the level of the signal delivered to the FM detector (18). In the detector (18), the output of the phase-locked oscillator (17) adds a component which is equivalent in phase and frequency to the carrier term received from the IF amplifier (16). This feed-forward signal from the phase-locked oscillator reduces harmonic distortion.
    Type: Grant
    Filed: March 2, 1984
    Date of Patent: September 17, 1985
    Assignee: AT&T Bell Laboratories
    Inventor: David N. Carson