All-digital quadrature modulator
CA 2003938 C · Owner: Borth, David Edward · Inventors: Borth, David Edward
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A CPFSK quadrature modulator (300) is disclosed utilizing an all-digital implementation. The serial data input signal (201) is formatted into parallel overlapping bits using a shift register (202), an up/down counter (206) and an interpolation counter, (204), and applied as address lines to in-phase and quadrature-phase memories (208 210). A multiple of the bit clock is used to address carrier generation ROMs (216 218). The carrier signal is then modulated by the in-phase and quadrature-phase data signals (212, 214, 222), converted to an analog signal by a D/A converter (250) and, low pass filtered (254) to generate the analog output signal (255). A single ROM (440) is utilized to implement …
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 27, 1989 and granted May 3, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 27, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 27, 2011.
- 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.