Feed-forward amplifier
CA 2233793 C · Owner: Nec Corporation · Inventors: Sakai, Kazuhiko
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides a feed-forward amplifier having a predistortion circuit to provide a sufficient compensation for a variation in temperature. When a predistortion circuit 3 is used to minimize distortion in a main amplifier 6, the circuit 3, a variable attenuator 4 a, variable phase shifter 5, and a main amplifier 6 are located in this order and a control circuit 19 controls the variable attenuator 4 and variable phase shifter 5 so that a carrier component, that is, an input signal, in a detected distortion component decreases to a minimum. In this manner when the, gain of the main amplifier 6 varies due to a variation in temperature, the preceding variable attenuator 4 and …
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 1, 1998 and granted May 29, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 1, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 1, 2020.
- 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.