Catv upstream signal transmission at nonharmonic video frequencies
CA 1212456 A · Owner: Zenith Electronics Corporation · Inventors: Citta, Richard W.; Sgrignoli, Gary J.; Mutzabaugh, Dennis M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a cable television (CATV) system improved upstream data communication is provided by the use of preferred frequencies. Harmonics of downstream video and audio carrier signals arising from cable discontinuities produce common mode nonlinear distortion. Cable discontinuities caused by a loose, defective or corroded connector operate as a downstream mixing diode. The crossand intermodulation products thus produced are avoided in the present invention by the use of upstream frequencies displaced from these harmonics. In a preferred embodiment two harmonically-related upstream carriers generated by a single signal source and centered between adjacent harmonic noise peaks provide reliable …
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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
- Granted October 7, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 7, 2003.
- 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.