FM demodulator including injection locked oscillator/divider
US4953010A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 25, 1989 |
| Grant date | Aug 28, 1990 |
| Priority date | — |
| Expiry date | Jan 25, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D3/24
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An FM demodulator comprises an injection locked oscillator/divider for receiving an input signal to be demodulated. The injection locked oscillator/divider is coupled via a divider to a frequency discriminator, such as a quadrature demodulator, for providing a demodulated output signal. A feedback loop is provided to afford the demodulated output signal to a varactor tuning circuit of the injection locked oscillator/divider so that the center frequency of the injection locked oscillator/divider is constrained to correspond with the frequency of the input signal. The FM demodulator provides improved threshold extension and demodulated video bandwidth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.