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
Optimized delivery of web application code
Luggage cart
Computing device with improved user interface for applications
Methods and systems for use in tracking targets for direction finding systems
Storage apparatus and storage apparatus management method performing data I/O processing using a plurality of microprocessors
Promoting content
Cooling structure for electronic device
  Randomly Featured Patents
Hydrogen sensor and hydrogen gas detecting apparatus
Apparatus and method for dynamic frequency adjustment in a frequency synthesizer
Communications headset
Catalyst, method of its production and its use for the production of vinyl acetate monomer
Lip-engaging trailer lock
Pipe joints and connectors therefor
Apparatus for injecting constant quantitative chemicals and a method thereof
Disposable absorbent articles having improved tape tab fasteners
Alkali metal anode/chalcogenide cathode reversible batteries having alkali metal polyaryl metallic compound electrolytes
Conversion and/or selectivity of a zinc titanate catalyst