Fiber optic transimpedance receiver
US4998012A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 1, 1989 |
| Grant date | Mar 5, 1991 |
| Priority date | — |
| Expiry date | Dec 1, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/69
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A transimpedance receiver for broad band optical signals, such as carry multichannel CATV signals or broad band data over an optical fiber which may vary in length (e.g. from 2 km to 20 km) such that the optical power at a photodetector of the receiver may vary widely depending upon where the receiver, and is installed in the fiber optic distribution system utilizes a broad band device, preferably a GASFET, the internal capacitance and gain of which enables amplification over the broad band frequency range without oscillation. Different values of transimpedance for converting the current signal from the photodetector into an output voltage at the output (the drain) of the device which is in a range within which the device is linear, and does not introduce distortion into the signal, is obtained by connecting, between the output and the input of the device, a feedback resistor selected from a group consisting of resistors of different value each dependent upon the optical power of the optical signal applied to the photodetector. The output voltage is coupled to an electrical transmission line which may be a low impedance coaxial line using a buffer amplifier incorporating a device o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.