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Expired Canadian patentCanada

Method and apparatus for amplifying a signal

CA 2176551 C · Owner: Crnkovic, James John · Inventors: Klomsdorf, Armin Werner; Crnkovic, James John; Kim, Jin Dong

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Abstract From the Canadian patent

A unique method and apparatus modifies the load impedance at the output of a power amplifier by varying a voltage variable capacitor (VVC) (310) to maximize the efficiency of the power amplifier (304). A comparator (509) generates amplifier control signal (211) based upon a detected power output signal (216) and a reference signal. In addition to providing power control, the control signal is also coupled to a VVC circuit (506) to control the output impedance of the power amplifier. In an alternate embodiment, a separate VVC control signal (527) based upon a comparison of the power control signal and the battery voltage is coupled to a VVC. In another alternate embodiment a second VVC, can …

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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 May 14, 1996 and granted June 15, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 14, 2016.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 14, 2018.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMay 14, 1996
GrantedJune 15, 1999
Term endedMay 14, 2016
Patent numberCA 2176551 C
Classification (IPC)H03F1/00 +2 more

Timeline

Timeline From CIPO dates

1997199920012003200520072009201120132015Application filedMay 14, 1996Patent grantedJune 15, 1999Term endedMay 14, 2016

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