Double mode surface wave resonators
CA 2135983 C · Owner: Suthers, Mark Spencer · Inventors: Suthers, Mark Spencer; Saw, John Choo Beng; Cameron, Thomas Philip
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A double mode surface wave resonator comprises two IDTs (inter-digital transducers), arranged side by side between reflection gratings on a surface of a, piezoelectric substrate to provide for coupling of surface waves therebetween each IDT, having interleaved electrodes extending from a common rail between the two IDTs and from a respective outer rail of the IDT. One or each of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator. The electrodes of the IDTs can be arranged in spatial synchronism with adjacent fingers of the reflection gratings to reduce spurious longitudinal modes.
Read the whole patent
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 November 16, 1994 and granted February 10, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 16, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 16, 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.