Direct qam modulator
CA 2202458 C · Owner: Klymyshyn, David M. · Inventors: Klymyshyn, David M.; Kumar, Surinder; Mohammadi, Abbas
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A direct QAM modulator for generating a high power QAM modulated signal at microwave frequencies comprises a hybrid to create the required RF signals for I and Q paths. In each path, a rat-race coupler is used to get the in phase and out of phase RF signal. The subsequent circuit blocks in each path consist of a single pole double throw switch (SPDT) switched by the polarity of the incoming data, a reflection attenuator implemented by, using forward biased pin diode terminations and controlled by the absolute values of the baseband pulse amplitude modulation (PAM) signal, and a variable reflection phase shifter to adjust for the phase error. To realize modulated signal filtering and 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 April 11, 1997 and granted February 6, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 11, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 11, 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.
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.