Surface wave devices for differential coherent detectors
CA 2198529 C · Owner: Kipens, George Alfred · Inventors: Saw, John Choo Beng; Kipens, George Alfred; Leib, Harry
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A surface wave device, for use in differential coherent detection in a commutation signaling communications system using N predetermined M-bit codewords propagates, surface waves for each codeword to a first coded output IDT (inter-digital transducer) comprising M parallel taps with a pitch t = T / M the taps having phases representing bits of the respective codeword, and to a second output IDT which is at a distance from an input IDT greater by T than the first coded output IDT to provide an additional delay of, one information symbol. The input IDT or each tap of each coded output IDT, has a length equal to t. The second output IDT can comprise a coded IDT or a delay tap, responsive to …
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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 26, 1997 and granted June 29, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 26, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 26, 2019.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.