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
Automated tuning in a virtual machine computing environment
Seat post having a non-uniform cross-section
Liquid crystal display panel
Pull through coronary sinus pacing lead
Light emitting device power supply circuit, and light emitting device driver circuit and control method thereof
Polypropylene bottles
Method for identifying bacteria in a sample
  Randomly Featured Patents
Playback preamplifier for magnetic tape recordings
Light source module and illumination apparatus
Self-attaching fastener and method of securing same to sheet material
Polyester film as support for dry film resist
Plasma supply device
Groundworking attachments for an outrigger stabilizer pad
Safety valve structure for hydraulic jacks
Latching device for sliding door/window
Charge coupled device having meandering channels