Technical Manual
Airbridge BTS3612A CDMA Base Station
System Principle
Chapter 3 Radio Frequency Subsystem
3-6
3.2.4 Indices
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Supported frequency band: 450MHz, 800MHz and 1900MHz
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Power voltage: +24V
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Power consumption: 51W
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Dimensions: 460mm
%
233.5mm
%
64mm (Length
%
Width
%
Depth)
Note:
BTRM supports the different frequency bands with different BTRM types, such as BTRM for 450MHz band,
BTRM for 800MHz band, BTRM for 1900MHz band. And this principle also applies to the other RF
modules including BHPA, CDU, DFU, DDU, and RLDU.
3.3 BHPA
3.3.1 Overview
Located at the left side of the BTRM, the BTS High Power Amplifier Module (BHPA)
amplifies the RF modulation signals output by BTRM. Its main functions are:
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RF power amplification: The BHPA performs power amplification for the RF
modulation signals from BTRM.
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Over-temperature alarm: When the temperature of power amplifier base board
exceeds a specified threshold, the BBFM will process the over-temperature alarm
signal generated by HPAU and report it to BTRM.
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Over-excited alarm: When the power level of BHPA input RF signal exceeds a
specified threshold, the BBFM will process the over-excited alarm signal
generated by HPAU and report it to BTRM.
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Gain decrease alarm: When the gain of the power amplifier drops over 6dB, the
BBFM will process the gain decrease alarm signal generated by HPAU and report
it to BTRM.
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Fan monitoring: The BBFM installed in BHPA performs such functions as fan
alarm and power amplifier alarm signal processing & reporting, and fan speed
adjustment.
3.3.2 Structure and Principle
The structure of BHPA module includes the following parts, as shown in Figure 3-3: