User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
2 Hardware Architecture
2-29
II. Structure and principle
The structure of BHPA module includes the following parts, as shown in Figure 2-15:
RF input
Coupler
Power
amplification
RF output
BTBM
CDU
BTRM
BBFM
BDCS
Sampling
port
+27VDC
BHPA
Alarm signal
Alarm signal
Alarm
circuit
BTRM
Circulator
HPAUz
Figure 2-15
Block diagram of BHPA module
1) High Power Amplifier Unit (HPAU)
HPAU mainly consists of two parts: power amplifier and alarm circuit. The power
amplifier amplifies the RF signals from BTRM. The amplified RF signals are then
sent to CDU or DFU via BTBM. Alarm circuit monitors the power amplifier status and
generates over-temperature alarm, over-excited alarm and gain decrease alarm
signals when necessary. The alarm signals will be sent to BBFM, where they will be
processed and reported to BTBM. The coupler is used to couple the RF output
signals to the sampling port for test purpose.
The output power of HPAU can be adjusted by controlling the RF output signal of
BTRM.
2) BTS BTRM Fan Monitor (BBFM)
BBFM processes fan alarm signals and power amplifier alarm signals, and sends
them to BTRM via BTBM, and then BTRM will report them to upper level. BBFM can
adjust the fan speed based on the ambient temperature and the actual BHPA output
power in order to lower the noise of fans.
III. Interface
External interfaces of the BHPA module are D-type combination blind mate
connectors, including: