The IRT RWT-3820 /
RWR-3820 Wide Band RF Fibre Optic Link is a modular system for transmitting
broadband RF 'L' band FM modulated signals over an optical fibre cable. The
system response is from 900 - 2150 MHz.
The link is designed for transferring the down converted 'L' band signals
from satellite dishes to main equipment buildings. Fibre optic cable
provides low signal attenuation with no gain or cable equalisation
requirements with the added benefit of immunity to RFI and EMI and
protection against lightning strikes.
The system is designed for single mode fibre (9/125 µm) at 1300 nm with a
path loss of up to 12 dB. The operating distance will depend upon the actual
cable and connector losses.
RF signal connections are made to 75Ω SMC connectors on the rear panels. BNC
and F adapters are provided.
Optical connections are made to SC/PC optical connectors on at the rear of
the module. Modules can be installed in IRT 1 RU or 3 RU frames.
Wide band amplifiers are used to drive the DFB LASER with the RF signals
applied to the module input. The signal level is set by a front panel
control for optimum signal to noise ratio. A pilot signal is added to the RF
path to monitor the RF path integrity at the receiver.
Pilot signal level and laser output LED indicators are provided as well as a
relay contact set for external alarm indication of laser power or DC supply
LNB power can be applied through a connector on the rear panel.
Photo-detector Receiver The receiver consists of an optical detector
diode module followed by an adjustable gain stage and amplifiers to provide
two RF outputs from the receiver.
The output signal level is adjusted to the required level as seen at the RF
Mon connector. This level is the same as the rear output signal level.
Pilot and optical signal level LED indicators are provided as well as a
relay contact set for external alarm indication of optical signal, pilot or
DC supply loss.