Apparatus and method for detecting intermodulation distortion in a radio frequency receiver
CA 2070768 C · Owner: Motorola, Inc. · Inventors: Johnson, Robert M. Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A radio frequency receiver (300) typically contains electronic devices commonly used in amplifying or mixing circuits (315) which are seldom ideal. The non-ideal characteristics of these devices lead to intermodulation (IM) distortion. A measurement of the amplitude of the received signal (301) is taken both unattenuated (503) and attenuated (507). The difference between the two measurements is compared (511) to predetermined limits (L1, L2 or L3) wherein the received signal (310) is determined to be valid invalid or unsure. valid received signal is demodulated in the receiver (300). An invalid signal, confirming the presence of IM distortion, is rejected. The unsure signal may be rejected …
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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 June 9, 1992 and granted March 2, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 9, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 9, 2014.
- 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
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.