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
Method and apparatus for encoding and decoding video based on first sub-pixel unit and second sub-pixel unit
Rule-based stimulation program search
Process for preparing substituted aromatic carboxylic acids
Method and system for determining a suppression factor of a suppression system and a lithographic apparatus
Automated hotfix handling model
Sub-resolution assist feature repair
  Randomly Featured Patents
Electronic ballast with controlled operating voltage
Staged deployment endograft
PET device
Telephone apparatus, systems, and processes to enhance access for TDD and/or TTY devices
Readerboard system
Data latch circuit and semiconductor device using the same
5,6-dihydro-napth[1,2-d]-imidazole, napth[1,2-d]imidazole, and chromane[3,4-d]imidazole derivatives
Fixation means for an endocardial electrode
Disc retainer device
Multifocal artificial ocular lens with a transparency varying with illumination