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Canadian application, no grantCanada

Pilot tone detector

CA 2233490 A1 · Owner: Nortel Networks Limited · Inventors: Williams, Robby Gordon

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

An apparatus and method for detecting the presence of a signal component in an arbitrary signal where the signal, component has a desired frequency. The apparatus includes an error signal generator and a detector. The error signal generator has an input for receiving a reference signal having a reference frequency, a second input for receiving the arbitrary signal having the signal component and an output for generating a difference signal dependent upon a difference in frequency between the reference frequency and the desired frequency. The detector has an input for receiving the difference signal and an output for producing a detector signal when the magnitude of the difference signal is …

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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 March 27, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 27, 2018.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 27, 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.
FiledMarch 27, 1998
GrantedNo grant recorded
Term endedMarch 27, 2018
Patent numberCA 2233490 A1
Classification (IPC)G01R23/00 +1 more

Timeline

Timeline From CIPO dates

1999200120032005200720092011201320152017Application filedMarch 27, 1998Term endedMarch 27, 2018

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.