Frequency translating coherent analog to digital conversion system for modulated signals
US5113189A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 1991 |
| Grant date | May 12, 1992 |
| Priority date | — |
| Expiry date | Jun 21, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/458
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A analog to digital (A/D) conversion system (10 or 20) receives a modulated analog signal, translates the frequency of the signal to a lower frequency, and converts the analog signal to a filtered digital signal. In one form, the conversion system (10) has an analog signal multiplier (16), and A/D converter (18), an oscillator (12) and a frequency divider (14). Frequency multiplier (16) translates the frequency of the analog signal, and A/D converter (18) converts the analog signal to digital form. Frequency divider (14) receives a clock signal from oscillator (12) and divides the frequency of the clock signal. Because the same clock signal is used for frequency translation and analog to digital conversion, a phase error is not introduced in the output digital signal. Additionally, the frequency divider (14) forces the frequencies of the analog and digital signals to be an integer ratio for subsequent demodulation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.