Modulator using low-pass filter as delay element
CA 2050756 C · Owner: Alcatel N.V. · Inventors: Muller, Fred-Egon
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A push-pull modulator stage (70) has two possible transmission paths, an electrically short path (7) and a phase delay path (6) with a phase delay element providing a phase shift of approximately 180°. The phase delay element has the form of a low-pass filter. In each of the two paths (6 7) a semiconductor, diode (D1, D2) is disposed in such a way that they sense the carrier (Uc) with a phase shift of 180° and correspondinyly, switch in unison if no modulation voltage (Um) is present thus, suppressing the carrier at the signal output (3). When a modulation signal (Um) is present, the push-pull balance is disturbed and the resistance of one of the two paths (6) becomes lower relative to the …
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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 September 5, 1991 and granted May 3, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 5, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 5, 2013.
- 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.