Digital fsk receiver using double zero-crossing
CA 2116042 C · Owner: Tulai, Alexander F. · Inventors: Tulai, Alexander F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a digital frequency shift keyed (FSK) signal receiver comprised of a band-pass filter having passbands corresponding to each modulation frequency of an FSK signal for, receiving and translating the FSK signal a first zero, crossing detector for receiving the translated signal and for generating a value signal having a higher or lower value during a 1 logic bit of the translated signal, and an opposite lower or higher value during a 0 logic bit of the translated signal, a second zero crossing detector for receiving the value signal and for outputting groups of 1's and groups of 0's the group, lengths depending on intervals between the higher and lower values.
Read the whole patent
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 February 21, 1994 and granted March 23, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 21, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 21, 2016.
- 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.