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
System and method for customized prompting
Zoom lens
Pressure roller and fixing device equipped with the same
Performance venue with dynamic mechanical load management system and method
Apparatus and method for transmitting/receiving data in a communication system
Selection of system parameters based on non-acoustic sensor information
Image processing apparatus and image processing method
  Randomly Featured Patents
Method and system for using extended fabric features with fibre channel switch elements
One piece throttle block for snowmobiles
Tool holding and working piece-clamping assembly for a machine tool
Radiofrequency contactor
Method for positioning a cylindrical article
Heat activated reinforcing sleeve
Level indicator
Vehicle headlight
Technique for improved linearity of high-precision, low-current digital-to-analog converters
Process for recovering tungsten values from alkali solutions