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Expired Canadian patentCanada

Frequency sweep circuit

CA 2196844 C · Owner: Nec Corporation · Inventors: Anzai, Makoto

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

A frequency sweep circuit including: a pull-in verification wave generator for generating a verification signal for pull-in verification; a sweep wave generator for generating a frequency sweep signal; a first adder for adding an output from the pull-in verification wave generator and an output from the sweep wave generator; a correlation determining unit for receiving a phase difference signal representing a phase difference between a received carrier wave and a recovered carrier wave, and an output from the first adder, determining presence/absence of a correlation between the phase difference signal and the output and outputting, a control signal for controlling the sweep wave generator; …

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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 February 5, 1997 and granted October 10, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 5, 2017.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 5, 2019.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledFebruary 5, 1997
GrantedOctober 10, 2000
Term endedFebruary 5, 2017
Patent numberCA 2196844 C
Classification (IPC)H04L27/00 +2 more

Timeline

Timeline From CIPO dates

1998200020022004200620082010201220142016Application filedFeb 5, 1997Patent grantedOct 10, 2000Term endedFeb 5, 2017

Sources & verification

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