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Expired Canadian patentCanada

Omnidirectional antenna

CA 2245658 C · Owner: Robertson, Duncan Alexander · Inventors: Robertson, Duncan Alexander; May, Peter Brian

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

An antenna system for providing radiation over substantially 360~ in azimuth by illuminating a conical reflector with a radiation beam having a frequency distribution with a local minimum which is coincident with the point of the reflector thus avoiding scattering. Preferably the radiation intensity distribution is annular, most preferably being Laguerre-Gaussian in nature.

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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 July 22, 2003. 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
GrantedJuly 22, 2003
Term endedFebruary 5, 2017
Patent numberCA 2245658 C
Classification (IPC)H01Q19/10

Timeline

Timeline From CIPO dates

1998200020022004200620082010201220142016Application filedFeb 5, 1997Patent grantedJuly 22, 2003Term 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.