Direct digital synthesizer driven phase lock loop frequency synthesizer with hard limiter
CA 2079320 C · Owner: Qualcomm, Inc. · Inventors: Gilmore, Robert P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A frequency synthesizer (100, 200) using a direct digital synthesizer (DDS) (102, 216) whose output signal is filtered by a bandpass filter (110, 218) and may be amplitude limited by a limiter (111 219) to reduce spurious noise. In one embodiment the, DDS (102) is coupled to a phase lock loop (114) which receives the DDS generated reference signal and a divide-by-N signal for generating an output frequency determined by the divide-by-N signal. In a second embodiment, the DDS (216) is incorporated within the feedback path of a phase lock loop (202) having an output frequency determined by an input reference frequency and the DDS step size controlled by a frequency control signal. …
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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 October 22, 1990 and granted September 19, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 22, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 22, 2012.
- 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.