Reference Manual Part 1

RBS 2106
Bias injector
The bias injectors are used to provide the TMA with DC power from the
TMA-CM, over the RX/TX feeder cables. The bias injector is mounted between
the antenna feeder and the CDU.
Number of units: 0 – 6
DC/DC Converter
The DC/DC converter can supply -48 V DC power to transmission equipment in
the TM compartment. It converts +24 V DC to -48 V DC.
Number of units: 0 – 2
DC Filter
The DC filter is the interface between a +24 V DC external power source, such
as a battery, and the IDM inside the RBS.
The DC filter has the following main functions:
• ElectroMagnetic Combatibility (EMC) filtering
• Connection of +24 V DC to the cabinet
• Distribution of +24 V DC power to the IDM
ddTMA
The ddTMA is to be mast-mounted and placed close to the antenna. It improves
the receiver sensitivity. The ddTMA saves feeder cables by duplexing RX and
TX signals to the same cable.
Number of units per cabinet: 0 – 6
DF
The Distribution Frame (DF) is a connection and OverVoltage Protection (OVP)
device for external alarms and PCM links. The DF protects equipment inside
the RBS from overvoltage and overcurrent which can occur in external lines.
Examples of equipment requiring OVP include transmission lines, ESBs and
external alarms.
Number of units: 1
19 (36)
EN/LZT 720 0222 Uen R6A