Handbook

800MHz BDA (Pasadena Figuero Tunnel)
Maintenance Handbook
H/book Number:-60-056100HBKM
Issue No:-1
Date:-21/10/2003
Page:-
10 of 52
2. OVERVIEW/SYSTEM DESCRIPTION
The AFL 800MHz Off Air Amplifier for the Pasadena Blue line project is an 8 way
channelised RF amplifier. It’s application is as an air interface between the donor radio site
and the tunnel leaky feeder system. The unit is housed in an environmentally protected IP65
steel wall-mount case. Handles are provided for carrying the unit and the door is fitted with
locks. The unit interfaces with ‘N’ type female connectors for RF connections and heavy duty
connectors for routing of AC power supply input and alarm output wiring.
The unit is housed in an environmentally protected IP65 steel wall-mount case. Handles are
provided for carrying the unit and the door is fitted with locks. The unit interfaces with ‘N’
type female connectors for RF connections and heavy duty connectors for routing of AC
power supply input and alarm output wiring.
To provide adequate selectivity in the Downlink and Uplink paths, combline design
duplexers are used at the input and output ports. To provide the required gain to reach the
required signal levels, low-noise amplifiers (LNA’s) are used in each path, these being
followed by power amplifier modules to provide the required intermodulation performance.
Gain adjustment is available locally using switched attenuators.
Note that “Downlink” refers to the RF path from FO receiver to the leaky feeder port and that
“Uplink” refers to the RF path from the leaky feeder port to the FO transmitter.