Digitally frequency-locking a radio transceiver to the received signal
CA 2034088 C · Owner: Ford, David K. · Inventors: Main, Douglas W.; Moller, Paul J.; Ford, David K.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A unique cellular telephone (100) digitally frequency locks to the received base station transmitter signal. The cellular telephone (100) includes a radio transceiver (106), a reference oscillator (104) and, microcomputer (102) with memory therein for controlling the operation thereof. The radio transceiver (106) includes a phase-locked loop (PLL) synthesizer 120, a receiver mixer (122) followed by one or more gain stages (124), a phase detector (126), and a divider (128). The PLL synthesizer (120) generates a signal locked to the reference oscillator (104) that is mixed with the incoming base station transmitter signal in the receive mixer (122) to generate an intermediate frequency …
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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 January 11, 1991 and granted May 17, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 11, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 11, 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.