Phase lock loop used as up converter and for reducing phase noise of an output signal
US6255912A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 1999 |
| Grant date | Jul 3, 2001 |
| Priority date | — |
| Expiry date | Sep 27, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L2207/12
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A modulated signal is translated to a broadcast frequency by a translation phase lock loop. In the translation phase lock loop the output frequency, which is the broadcast frequency, is mixed with a translation frequency, and the resulting translated frequency is compared to the modulated signal. If an amplitude modulator is inserted into the translation loop, the phase comparison/feedback nature of the phase lock loop will tend to cancel the phase noise introduced in the amplitude modulation process. Any other circuits placed within the loop will tend to have any phase noise they introduce, which is in the phase lock loop bandwidth, canceled by the loop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.