Including Logic Element (e.g., Logic Gate Or Flip-flop) Patents (Class 332/101)
  • Hybrid frequency shift keying modulator and method
    Patent number: 4878035
    Abstract: A hybrid frequency shift keying modulator and method produces binary FSK by simultaneously applying a digital modulating signal to the DDS section of a frequency synthesizer along with a coordinated analog modulating signal as direct frequency modulation of the accompanying PLL section. Low frequency performance is derived from the characteristics of the DDS modulation and the high frequency performance and accurate wave shape reproduction are derived from the modulation of the direct FM section.
    Type: Grant
    Filed: May 27, 1988
    Date of Patent: October 31, 1989
    Assignee: Wavetek RF Products, Inc.
    Inventors: John A. Vendely, David M. Badger