Surface acoustic wave filter
CA 2183281 C · Owner: Murata Manufacturing Co. Ltd. · Inventors: Ushiroku, Tadamasa
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A surface acoustic wave (SAW) filter has a ladder-shaped circuit in which first one-port SAW resonators are connected between an input terminal and an output terminal as series resonators and second one-port SAW resonators are connected as parallel resonators. The antiresonant frequency of the second one-port SAW resonators matches the resonant frequency of the first one-port SAW resonators. The distances between interdigital transducers and reflectors of the second one-port SAW resonators are specified such that a spurious component is generated at a frequency between the resonant frequency of the second one-port SAW resonators and the transmission band of the filter in order to improve …
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 August 14, 1996 and granted November 2, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 14, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 14, 2018.
- 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.