Hybrid directional coupler for a radar system
CA 2020573 A1 · Owner: Davis, John W. · Inventors: Davis, John W.; Davis, John W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention is directed to a directional coupler for coupling together a radar frequency transmitter to a combined transmitting and receiving antenna, a power absorber and a receiver. A tunable stub is employed to reflect a selected amount of transmitted energy to the local oscillator (LO) of the receiver for mixing with the incoming received signal. The coupler can be constructed from any known type RF transmission line suitable for passing or coupling signals of radar frequencies. A significant amount of the transmitter power is absorbed in a power absorbing RF load allowing only a small amount to be transmitted from the antenna and a still smaller amount fed back as LO to the receiver. …
Read the whole patent
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 July 6, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 6, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 6, 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.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.