Adaptive multiple sub-band common-mode rfi suppression
CA 2237460 A1 · Owner: Northern Telecom Limited · Inventors: Lefebvre, Pierre Donald; Yeap, Tet Hin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A noise suppression circuit for a two-wire communications channel comprises a hybrid device, for example a hybrid transformer or circuit for providing a differential mode, signal corresponding to a differential signal received from the two-wire channel. A summing device extracts from the two-wires of the channel a common mode signal and supplies it to a noise estimation unit which derives from the common mode signal an estimate of a noise level in at least one frequency band having a bandwidth considerably narrower than an operating bandwidth for the channel. The noise estimation unit adjusts the amplitude of the noise estimate to correspond to the residual noise in the differential mode …
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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 May 13, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 13, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 13, 2020.
- 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.