Voltage converter for a frequency synthesizer
US4484153A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 1981 |
| Grant date | Nov 20, 1984 |
| Priority date | — |
| Expiry date | Apr 6, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/405
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In a frequency synthesizer phase locked loop including a reference oscillator, a variable reference divider (.div.M), a sample and hold phase detector, a loop filter, a voltage controlled oscillator and a variable divider (.div.N), a voltage converter for controlling the voltage of a control input to the voltage controlled oscillator is disclosed. In the preferred embodiment, the voltage converter has its input connected to the output of a first reference divider in the variable reference divider (.div.M) and its output connected to a control input (varactor diode) of the voltage controlled oscillator. The voltage converter clamps the divider reference signal from the first reference divider and provides a negative voltage level output to bias the varactor diode of the voltage controlled oscillator. Thus, the tuning range of the frequency synthesizer is increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.