Saw device tapped delay lines
CA 2096629 C · Owner: Nortel Networks Corporation · Inventors: Cameron, Thomas Philip; Kennard, Paul Alan; Saw, John Choo Beng
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A SAW (surface acoustic wave) device tapped delay line comprises a continuous pattern of bifuecated inter-digital fingers (48) having a constant pitch of .lambda./2 and forming a first IDT (interdigital transducer) (12), a plurality of second IDTs (14); substantially identical to one another and arranged with a predetermined pitch P for consecutively receiving a SAW propagated from the first IDT with respective propagation delays and grounded dummy fingers , (42) in regions between adjacent IDTs. The first IDT is apodized in accordance with a Hermitian response to provide it with a pass band (58) centered at a first frequency (140 MHz) and .lambda. is the wavelength of a SAW at a second …
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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 December 17, 1991 and granted October 26, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 17, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 17, 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.