Wideband modulated fractional-N frequency synthesizer
US6211747A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 1999 |
| Grant date | Apr 3, 2001 |
| Priority date | — |
| Expiry date | May 28, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/1974
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A direct modulation multi-accumulator fractional-N frequency synthesizer 1 for generating a carrier signal 150 modulated by a modulation signal 170, 121 is disclosed. The frequency synthesizer includes a Voltage Controlled Oscillator, VCO 50, having a tuning port for controlling the frequency of the signal 110 output by the VCO, a variable divider 20 and a multi-accumulator sequence generator 21 for controlling the variable divider, a reference signal generator 50, a phase detector 30 and a low pass filter 40. These elements are arranged to form a Phase Locked Loop arrangement, the directly modulated output signal of which is taken from the output of the VCO, wherein in-band modulation is performed by varying the variable divider and out-of-band modulation is performed by directly applying the modulating signal to the VCO tuning port.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.