User's Manual

SPA9323-30C Installation & Service Manual

044-05178 Rev.A 4-2 October 2004

4-4.1 Driver Amplifier

The driver amplifier is a two-stage amplifier that provides approximately 28 dB of gain in the 60

MHz frequency band from 1930 to 1960 MHz. The amplifier is mounted directly on a heat sink,

which is temperature monitored by a thermal sensor.

4-4.2 Main Amplifier

The main amplifier is a single-stage Class AB amplifier with approximately 13 dB gain and a

P1dB of +50 dBm. The amplifier’s output is protected from output mismatches. The amplifier is

designed to meet spectral mask requirements for GSM and EDGE signals when operated up to

+45.2 dBm. The amplifier is mounted directly on a heat sink.

4-4.3 Power Distribution

The amplifier module operates on a –48 VDC nominal power supply consuming 2.9 amps (typi-

cally) current at full power. A DC/DC converter supplies internal circuitry with +26 VDC and +5

VDC.

4-4.4 Multifunction Board

The multifunction board enables communication between the amplifier and the base-transceiver

station in which it is installed, and stores information about the amplifier. It includes gain control

and two gain stages providing a 7 dB gain. The multifunction board also monitors several ampli-

fier performance parameters and reports output power so that the BTS can maintain the output

power within specified limits. When these parameters are beyond acceptable levels, the amplifier

alarms. The multifunction board is mounted directly on a heat sink, which is temperature moni-

tored by a thermal sensor.

The alarms are:

Temperature Alarm - If the internal temperature reaches 90°C, the PA shuts down and com-

municates an alarm through the digital interface.

DC/DC Alarm - If the output voltage of the converter falls below 23.5V, the PA shuts down

and communicates an alarm through the digital interface.

Over-current Alarm - If the output current of the DC/DC converter goes above a nominal

threshold (7.5 A), the PA shuts down and communicates an alarm through the digital

interface.

Communication Alarm - If the serial interface detects an error in transmission (parity, over-

run, framing), an alarm is sent for one burst only during the very next burst. The PA

operation is not affected.