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Expired Canadian patentCanada

Frequency converter circuit

CA 2204045 C · Owner: Kojima, Toshiharu · Inventors: Kojima, Toshiharu

CIPO record

Overview

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

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Abstract From the Canadian patent

Within a differential detection demodulator a received, signal is first quantized by a limiter amplifier and then subjected to frequency conversion by a frequency converter. The frequency converter circuit converts a frequency of a first 2-level signal using a second 2-level signal having a frequency distinct from the frequency of that first signal and includes: an exclusive OR element for obtaining a logical exclusive OR element of the first and second signal; running average generator means, coupled to the exclusive OR element, for generating a signal corresponding to k times a running average of an output of the exclusive OR element k, being a positive integer; and hard decision means …

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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 December 24, 1992 and granted September 26, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 24, 2012.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 24, 2014.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 24, 1992
GrantedSeptember 26, 2000
Term endedDecember 24, 2012
Patent numberCA 2204045 C
Classification (IPC)H04L27/22

Timeline

Timeline From CIPO dates

1993199519971999200120032005200720092011Application filedDec 24, 1992Patent grantedSep 26, 2000Term endedDec 24, 2012

Sources & verification

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