Filter
CA 2020365 A1 · Owner: Hales, Jeff · Inventors: Hales, Jeff
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A filter", A filter for use in radio apparatus the filter comprising a, plurality of isolated ceramic resonators each having an input and a plurality of variable capacitance means for electronically tuning respective ceramic resonators and that the inputs of adjacent ceramic resonators are coupled via a first coupling path and also via a second coupling path, the first coupling path being composed of a fixed capacitance network and the second coupling path being composed of a cascade arrangement of a first said variable capacitance means and a second said variable capacitance means the relative values of the, capacitances forming the first and second coupling paths being such that the …
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 4, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 4, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 4, 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.