Automatic frequency control in the presence of data
CA 2003580 C · Owner: Borth, David Edward · Inventors: Borth, David Edward; Kepler, James Frank Michael
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
There is provided a method of and apparatus for Automatic Frequency Control (AFC) in the presence of data. It comprises removing the effects of data modulated onto the carrier detecting, the frequency difference between the carrier frequency and the phase of the reference oscillator, and adjusting the frequency of the reference oscillator to eliminate the frequency difference. It is further characterized by digitizing the modulated carrier in quadrature, sampling the modulated carrier in quadrature at a multiple of the modulated bit rate, rotating phases toward arctangent (I/Q)=0 to remove the effects of quadrature data (I/Q) modulated onto the carrier, detecting the frequency difference …
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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 November 22, 1989 and granted November 9, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 22, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 22, 2011.
- 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.