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Expired Canadian patentCanada

Single-block filter for antenna duplexing and antenna-switched diversity

CA 2025758 C · Owner: Kim, Jin Dong · Inventors: Kommrusch, Richard S.; Kim, Jin Dong; Moutrie, Michael F.

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

Abstract of the Disclosure, A single-block ceramic filter (102) is coupled to two antennas (142 and 144) for providing both antenna duplexing and antenna-switched diversity in a duplex radio transceiver (100). One antenna (142) is coupled by the filter (102) to a transmitter (132), and both antennas (142 and 144) are switchably coupled by the filter (102) to a receiver (130) by diversity control circuitry (101) in response to a diversity control signal (137). A microcomputer (134) in the transceiver (100) is coupled to the receiver (130) for monitoring the received signal strength (135). When the received signal strength (135) drops in level indicating that the signal being received on one …

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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 September 19, 1990 and granted July 12, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 19, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 19, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 19, 1990
GrantedJuly 12, 1994
Term endedSeptember 19, 2010
Patent numberCA 2025758 C
Classification (IPC)H03H9/48 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedSep 19, 1990Patent grantedJuly 12, 1994Term endedSep 19, 2010

Sources & verification

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