Transceiver bandwidth extension using double mixing
CA 2227673 C · Owner: Northern Telecom Limited · Inventors: Rowland, Andy; Oberhammer, Wolfgang
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A radio transceiver system uses a single variable local oscillator frequency source which is used in mixing both before and after a band-pass filter. This causes a reduction in band-pass filter bandwidths. In an all-band transceiver for PCS for example the effect of this reduced bandwidth requirement is to increase the spacing between the transmit bands and the receive bands and thereby enable a reduction in transmission noise interfering with the reception bands.
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 January 21, 1998 and granted December 16, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 21, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 21, 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.