Zero signal state detecting circuit
US4795919A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1987 |
| Grant date | Jan 3, 1989 |
| Priority date | — |
| Expiry date | Jun 1, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R19/175
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention provides a zero signal state detecting circuit for detecting zero signal state of the signal in an optical receiver or optical repeater. The zero signal state detecting circuit in accordance with the present invention comprises a level shifting circuit, a smoothing circuit, a first comparator, a peak detecting circuit and a second comparator. The output signal from the timing circuit to produce two output signals is shifted by the level shifting circuit. One of the two outputs of the level shifting circuit is smoothed by the smoothing circuit. The output of the smoothing circuit and the other one of the outputs of the level shifting circuit are compared by the first comparator and the output is detected by the peak detecting circuit. The output of the peak detecting circuit is compared by the second comparator against a reference voltage, and the zero signal state of the optical receiving signal is detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.