Resources Contact Us Home
Demodulator for sampled data FM signals

Image Number 4 for United States Patent #4910469.

A sampled data FM demodulator samples the FM signal at intervals of (2n.pi.+.pi./2) radians relative to the FM carrier. Pairs of samples S.sub.n and S.sub.n+1 are square and multiplied together to generate sample values S.sub.n.sup.2, S.sub.n+1.sup.2 and S.sub.n S.sub.n+1. These sample values are lowpass filtered in a filter having a cutoff frequency which substantially attentuates at least the second harmonic of the FM carrier. The low pass filtered samples are then combined according to the relation S.sub.n S.sub.n+1 /.sqroot.S.sub.n.sup.2 S.sub.n+1.sup.2 to generate demodulated output samples.

  Recently Added Patents
Telecommunications system and method
Method and device for evaluating evolution of tumoural lesions
Image forming apparatus
Adjustable draw bar for trailer hitches
Thwarting keyloggers using proxies
Wide bandwidth hybrid antenna for combination EAS and RFID label or tag
Signal generator
  Randomly Featured Patents
Information processing apparatus, information processing method, and program conversion apparatus, in which stack memory is used with improved efficiency
Thin film transistor substrate for a liquid crystal display wherein a black matrix formed on the substrate comprises an inner aperture formed completely within the black matrix
Distillation unit for solvent
Flood bar and squeegee for printing apparatus
Spyware scanning and cleaning methods and system
Intermittently illuminated fishing lure with travelling electrical contact
Charge pump with reduced energy consumption through charge sharing and clock boosting suitable for high voltage word line in flash memories
Method and apparatus for heating a fuel
Cash safe
Animal limb protective boot