User Manual

CDU-C Combining and Distribution Unit
TXBP The TXBP lets TX signals between two specified
frequencies pass and removes unwanted out-of-band
signals
Hybrid Combiner
The hybrid combiner combines two TX signals to a
common output. It is a broadband combiner, but there
is a 3 dB combing loss in the TX path.
Duplexer
The duplexer allows simultaneous transmission and
reception on the same antenna. It lets the TX signals
pas
s to the antenna and let the RX signals from the
antenna pass to the RX part.
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 consists of two RX chains, A and B, and includes the following
units:
• A duplex filter (duplexer) (GSM 900 version only)
•Ab
ias injector (GSM 1800 and GSM 1900 versions only)
• An RX Band-Pass filter (RXBP)
• An RX Distribution Amplifier (RXDA)
•Sp
litters
Duplexer See Page 7.
Bias Injector The bias injector in the GSM 1800 and GSM 1900
versions provides power to and supervises an optional
TMA.
RXBP
The RXBP lets RX signals between two specified
frequencies pass and removes unwanted out-of-band
signals.
RXDA RXDA amplifies the RX signal for transmission to the
splitter.
Splitter
The splitter divides the RX signals for distribution to the
TRUs. It has no filtering or gain.
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EN/LZT 720 0277 Uen R1A