A switchable low-pass filter
CA 2337873 A1 · Owner: Zhou, Shu-Ang · Inventors: Zhou, Shu-Ang
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A low-pass or band-rejection filter for microwave frequencies has a substantially planar structure and is constructed of a transmission line having inductor portions (10) and wider capacitor portions (11). The inductor portions are designed as linear microstrip elements having widths being varied by making areas (13) at the sides of the linear elements (10) superconducting. In changing the widths of the transmission line also the inductances thereof are changed accordingly. The areas (13) at the sides of the microstrip elements comprise rather narrow areas located directly at the central normal , metal conductor (9). These narrow areas (13) have in the non-superconducting state some …
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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 July 16, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 16, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 16, 2021.
- 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.