Audio frequency recovery -- dc restorer circuit after demodulation for cordless phone applications
CA 2248918 A1 · Owner: Nortel Networks Corporation · Inventors: Cana, John-Paul P.; Smiley, Michael T.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An audio frequency recovery--DC restorer circuit after demodulation that includes an operational amplifier a diode, a, capacitor and resistor circuitry arranged to supply a reference voltage signal Vref to the operational amplifier. The operational amplifier is also coupled with a demodulated audio frequency baseband signal via the capacitor. The demodulated audio frequency baseband signal is in a filtered condition free of high frequency noise that may otherwise affect quality and having an average voltage Vavg at a level. The operational amplifier clamps the demodulated audio frequency baseband signal above or below the Vref depending upon an orientation of the diode so as to set a new …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed September 28, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 28, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 28, 2020.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.