Frequency modulation system for a frequency synthesizer
US4494090A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 1984 |
| Grant date | Jan 15, 1985 |
| Priority date | — |
| Expiry date | May 25, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/405
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A voltage controlled oscillator includes a main varactor diode coupled to a frequency resonating circuit to produce an output frequency in response to a control voltage. A secondary varactor diode of an appreciably lower voltage to frequency sensitivity ratio is coupled to the main varactor diode. A modulation input circuit is coupled to the secondary varactor diode to enable modulation of the resonating output frequency. A linearizing circuit is coupled to the secondary varactor diode and tracks the main varactor diode capacitance to continuously adjust the bias voltage of the secondary varactor diode to provide constant carrier modulation deviation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.