Narrow-band filter having a variable center frequency
CA 2115182 C · Owner: Nec Corporation · Inventors: Ichihara, Masaki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a narrow-band filter for filtering an input signal having a predetermined frequency and comprising first through n-th low-pass filters (13-l to 13-n) which are connected in parallel to one another a switching, circuit time divisionally connects the first through the n-th low-pass filters between input and output terminals (11, 12). The first through the n-th low-pass filters thereby, time divisionally filters the input signal for first through n-th filtering durations respectively. A, control circuit (30) is supplied with a frequency designation signal designating the predetermined frequency and controls the switching circuit to change at least one of the first through the n-th filtering …
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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 8, 1994 and granted May 27, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 8, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 8, 2016.
- 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.