Phase monitor used in optical receiver
US7676162B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 2006 |
| Grant date | Mar 9, 2010 |
| Priority date | — |
| Expiry date | Jul 10, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/677
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Branches are grouped into a group 1 including first and second branches, and a group 2 including third and fourth branches. The signal after being passed through a dual pin photodiode in one branch included in the group 1 and being at the earlier stage of a CDR circuit is obtained. Also, from the later stage of the CDR circuit in the other branch in the group 1 is obtained. The obtained signals are passed through low pass filters, and an average value over a plurality of symbols is obtained. The signal from the earlier stage of the CDR circuit is multiplied by the signal from the later stage, and they are averaged. The obtained value reflects the phase difference of the two delay interferometers in the group 1. The group 2 is monitored by using the same method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.