User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
2 Hardware Architecture
2-35
l
BTS transmitting signals, which are transferred to the cabinet-top antenna
interface through the RF cable connected with the N-connector at the front side
of the module.
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BTS receiving signals, which are transferred from the cabinet-top antenna
interface to DFU for filtering through the RF cable connected with the
N-connector on the front side of the module.
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BTS receiving signals output from the duplexer and diversity receive filter. They
are sent to RLDU via the blind mate connector on the backside.
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Forward/reverse coupled RF signals, which are sent to RLDU via the blind
mate connectors on the backside.
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Forward/reverse coupled test signals, which are outputted through the standard
SMA connector on the front side.
IV. Index
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Supported frequency band: 450MHz band
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Module size: L
%
W
%
H=450mm
%
100mm
%
344.8mm
2.3.7 Dual Duplexer Unit (DDU)
I. Overview
DDU completes the following functions:
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Isolation and low-pass filtering of two receiving and transmitting signals.
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Providing two DC feeds to T-type tower-top amplifier.
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Voltage Standing Wave Ratio (VSWR) test on transmit channels in both
forward and backward directions.
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Coupling test of transmitting and receiving signals.
Key components within DDU include Bias -T DC feed connector, low-pass filter,
duplexer, and bi-directional coupler.
II. Structure and principle
DDU structure is shown in Figure 2-19.
