Band pass filter
CA 2003757 C · Owner: Umino, Isamu · Inventors: Kobayashi, Fumihiko; Umino, Isamu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A band pass filter is comprised of one or more filter units each having a V-shaped microwave strip line provided with two variable capacity elements at its two open ends and a high frequency elimination element connected to the apex thereof through which a control voltage for the variable capacity elements is applied.
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 November 23, 1989 and granted June 21, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 23, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 23, 2011.
- 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.