Pulse count type FM demodulator
US4800338A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 1987 |
| Grant date | Jan 24, 1989 |
| Priority date | — |
| Expiry date | Jun 29, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K9/06
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An FM demodulator having improved demodulation sensitivity, and suitable for monolithic integration. As demonstrated in various embodiments, increased sensitivity is made possible= by narrowing the demodulation band on a low frequency side. According to the various embodiments, a monostable multivibrator or first pulse generator receives an input signal and provides an output having first and second states having a combined duration equal to one period of the input signal, or alternatively equal to one-half period of the input signal. A second pulse generator, responsive to the output of the first pulse generator, generates another output having third and fourth states whose combined duration is the same as the combined duration of the first and second states. Demodulation is accomplished finally through a low-pass filter, which integrates the output of the second pulse generator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.