Angle modulated wave demodulation system
US4107478A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 1976 |
| Grant date | Aug 15, 1978 |
| Priority date | — |
| Expiry date | Jun 21, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04S3/006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An angle modulated wave demodulation system demodulates an input angle modulated wave by means of a phase locked loop system which comprises a phase comparator, which is operated responsive to an input angle modulated wave. A voltage controlled oscillator is supplied with a part of the output of the phase comparator which controls its oscillation frequency. The oscillator supplies its oscillation frequency to the phase comparator. The phase locked loop system has a lock frequency range which decreases its width when the level of the input angle modulated wave is below a predetermined level. The portion of this lock range in which the width of the lock range decreases is positively utilized. The voltage controlled oscillator oscillates at a frequency equal to the center frequency of the carrier of the input angle modulated wave, when the phase locked loop becomes unlocked.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.