Frequency synthesizer for a wireless communication system
US7019571B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 31, 2004 |
| Grant date | Mar 28, 2006 |
| Priority date | — |
| Expiry date | Apr 25, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/0893
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A dual path frequency synthesizer is disclosed which includes a controlled oscillator and a phase detector that determines the phase difference between an output signal of the controlled oscillator and a reference signal. The synthesizer also includes a charge pump that is coupled to the phase detector. The synthesizer includes a direct path loop filter which is coupled to a charge pump output. The synthesizer also includes an integrating path loop filter which is coupled to another charge pump output and which has substantially the same topology as the direct path loop filter. The direct path loop filter and the integrating path loop filter are substantially matched with one another. The charge pump pumps charge into the direct and integrating path loop filters in response to the phase difference between the reference signal and the output signal of the controlled oscillator as determined by the phase detector. The controlled oscillator is effectively decoupled from the direct and integrating path loop filters at those times when the charge pump is pumping charge into the filters. This reduces the impact of signals from the charge pump that might otherwise cause degradation in the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.