Method and apparatus to perform digital demodulation by measuring periods between zero crossings
US5272448A · kind A · utility
4Cited by
4References
7Claims
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Key dates
| Filing date | Apr 29, 1992 |
| Grant date | Dec 21, 1993 |
| Priority date | — |
| Expiry date | Apr 29, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K9/06
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digital demodulator provides efficient demodulation of frequency modulated, pulse-width modulated, and other temporally modulated signals. Without employing an analog-to-digital converter, modulating signal information is extracted from a modulated signal as numerical information. For frequency demodulation, a high gain stage is applied to an incoming FM signal to produce a corresponding sequence of square waves. The period between zero-crossings of the square waves is accurately measured to within one clock pulse using a high-speed clock and at least one counter to produce a demodulated signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.