Frequency shift keying demodulator
US8170422B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 2005 |
| Grant date | May 1, 2012 |
| Priority date | — |
| Expiry date | Aug 5, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/212
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
It is an object of the present invention to provide an FSK demodulator which can be used in the optical information and telecommunications and the like, and which can appropriately demodulate an FSK signal by compensating a delay of an optical FSK modulated signal due to dispersion and the like of an optical fiber.The above-mentioned problem is solved by a frequency shift keying (FSK) demodulator (1) composed of a branching filter (2) for branching an optical signal according to wavelengths thereof; a delay adjusting apparatus (3) for adjusting a delay time of two lights branched by the branching filter; a first photodetector (4) for detecting one optical signal branched by the branching filter; a second photodetector (5) for detecting a remaining optical signal branched by the branching filter; and a means (6) for calculating a difference between an output signal of the first photodetector and an output signal of the second photodetector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.