FM demodulation and frequency tuning for a phase-locked loop
US5640126A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 11, 1996 |
| Grant date | Jun 17, 1997 |
| Priority date | — |
| Expiry date | Jan 11, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L2207/06
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The invention provides a demodulation PLL wherein: the first position of a switch, which is controlled by a control circuit, respectively connects the outputs of a mixer and a LP filter to high gain and low gain inputs of an oscillator when frequency signals at the inputs of the mixer have not converged sufficiently, i.e. during the PLLs tuning mode; the second position of the switch respectively connects the outputs of the mixer and the LP filter to the low gain and high gain inputs of the oscillator when the frequency signals at the inputs of the mixer and the signal levels on the input and output of the filter have converged sufficiently, i.e. during the PLLs demodulation mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.