FM demodulator using a switched capacitor phase shifter
US5751188A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1996 |
| Grant date | May 12, 1998 |
| Priority date | — |
| Expiry date | Dec 10, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D7/1483
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In order to process an input signal exhibiting a frequency modulation about an intermediate frequency, the demodulator includes a first mixer for producing a first signal exhibiting the frequency modulation about a transposition frequency lower than the intermediate frequency; a switched-capacitor phase-shifter receiving the first signal so as to produce a second signal exhibiting, with respect to the first signal, a phase-shift varying substantially linearly with frequency about the transposition frequency; two substantially identical low-pass filters receiving the second signal and the first signal respectively; and a second mixer for mixing the signals produced by the first and second low-pass filters, in order to deliver a baseband output signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.