Reference Manual

Table Of Contents
Unit Decription, CDU-G and CDU-F
8.1.2 CDU-F
P007450B
CDU-F
Figure 70 CDU-F
CDU-F has four lter cavities grouped internally two and two. The two
lters form a combiner for two TX signals and can be combined with a
CNU to a combiner for four signals, or connected to another CDU to
form a combining network for six signals.
The combined signals are fed through a lowpass TX lter to a duplex
lter. The duplex lter allows the use of a single antenna both for
transmitting and receiving. The duplex lter is connected directly to the
antenna connector on top of the CDU. The duplex lter also lters the
RX signal arriving to the same antenna. This ltered RX signal is
amplied in a two-stage low noise amplier and then ltered in a
lowpass lter.
CDU-F also has an extra RX chain for diversity. This extra RX chain is
similar to the duplex RX chain.
All necessary connections for the TX combining network are done on
the front of the CDU with a Combining Network Unit (CNU).
EN/LZT 720 0008 R1A
2001-06-26
131 (421)
© Ericsson Radio Systems AB
All Rights Reserved