Direct conversion receiver with dithering local carrier frequency for detecting transmitted carrier frequency
CA 2014916 C · Owner: Minami, Yoichiro · Inventors: Minami, Yoichiro
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An FSK receiver includes first and second channel paths to which the received FSK signals are applied. Each channel path includes a mixer circuit, a low-pass filter connected to the mixer circuit, and a limiting amplifier connected to the low-pass filter. A voltage-controlled oscillator generates a local carrier and a phase shifter applies its output to the mixer circuits with a 90° phase difference therebetween. A frequency detector is coupled to one of the limiting amplifiers for generating a signal representative of the deviation frequency minus the offset frequency of the received FSK signal. An average circuit detects an average value of the signal from the frequency detector. A …
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 April 19, 1990 and granted November 8, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 19, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 19, 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.