Frequency synthesizer utilizing pulse-width modulation of digital VCO control signal
US5216374A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 1991 |
| Grant date | Jun 1, 1993 |
| Priority date | — |
| Expiry date | Jul 3, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/00
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A frequency synthesizer includes a voltage-controlled oscillator (VCO) for producing a VCO output signal within a given frequency range, wherein the VCO produces the VCO output signal at a predetermined frequency in response to an analog VCO control signal that indicates the predetermined frequency; a microcontroller for processing a frequency measurement value with a reference value to provide a digital VCO control signal that indicates the value of the analog VCO control signal required for causing the VCO to produce the VCO output signal at the predetermined frequency and for pulse-width-modulating the digital VCO control signal; and a low-pass filter for converting the pulse-width modulated VCO control signal into the analog VCO control signal. The frequency synthesizer includes a plurality of VCOs which provide VCO output signals at a plurality of predetermined frequencies in response to respectively separate PWM VCO control signals provided by a microcontroller that processes measurement values for the respective VCOs with reference values for the respective VCOs. Coarse and fine components of the digital VCO control signal are pulse-width modulated and converted to provide h…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.