User Manual

CDU-A Combining and Distribution Unit
TXBP The TXBP lets TX signals between two specified
frequencies pass and removes unwanted out-of-band
signals
Duplexer
The duplexer allows simultaneous transmission and
reception on the same antenna. It lets the TX signals
pass
to the antenna and lets the RX signals from the
antenna pass to the RX part.
Signals of other frequencies are blocked by the filter.
MCU
The
MCU measures forward and reflected signal levels
at the CDU output. The signals are forwarded to the
TRU via cables on the front of the CDU.
4.2 RX Part
The RX part handles the transmission of signals from the antenna to the TRUs.
The
RX part for each antenna consists of the following units:
• A bias injector (GSM 1800 and GSM 1900 versions only)
• A duplex filter (duplexer) (GSM 900 version only)
•AnR
X Distribution Amplifier (RXDA)
•Asplitter
• RX Band-Pass filters (RXBP)
Bias Injector
The GSM 1800 and GSM 1900 versions contain two
bias injectors to provide power to and supervise an
optional TMA.
Duplexer See above.
RXDA
RXDA amplifies the RX signal.
Splitter
The splitter divides the signal from the RXDA into two
branches.
RXBP The RXBP lets RX signals between two specified
frequencies pass and removes unwanted out-of-band
signals.
7 (10)
EN/LZT 720 0235 Uen R1A