User's Manual

PRELIMINARY Booster Amplifier Subrack System Integration Manual
044-05075 Rev. B
1-1
January 2001
Section 1. General Description
1-1 Introduction
This manual contains information and procedures for the installation, operation, and maintenance
of Powerwave Technologies, Inc.’s (Powerwave’s) Booster Amplifier Subrack (BAS) system. This
manual is organized into the following sections:
Section 1. General Description Appendix A: Backplane Wiring Diagram
Section 2. Installation Appendix B: Distribution PCB Pinout Location
Section 3. Operating Instructions Appendix C: Power Setting Procedure
Section 4. Principles of Operation
Section 5. Maintenance
Section 6: Troubleshooting
1-2 General Description
Engineered to operate in a 2-way transceiver paging base station, the BAS system is a linear,
Multi-Carrier Power Amplifier (MCPA) system that operates in the 5 MHz frequency band from
935 MHz to 940 MHz. The system integrates the model MCR20930-1-2 Booster Amplifier
Subrack (BAS) with two model G3L-900-50-005 MCPAs to deliver a composite RF output of
75.8 Watts (nominal), after combined losses. The system can also integrate two model G3L-900-
60-005 MCPAs to deliver a composite RF output of 91 Watts (nominal), after combined losses.
Designed to function as a subrack (see Figures 1-2 thru 1-6) in the host base station, the enclo-
sure has a one inch (right and left side) flanged front panel and eight mounting holes (four on
each side) to secure the Subrack into place (refer to Figure 1-3 for mounting hole locations). To
aid in maintaining the system’s operating temperature, the BAS is equipped with two cooling fans
mounted on the front access door (see Figures 1-3 and 1-4). The G3L-900-50-005 amplifier dis-
places 1,672 BTUs of heat at full power. The G3L-900-60-005 amplifier displaces approximately
1,900 BTUs of heat at full power.
The composite input signal is applied to a 30dB 10W input attenuator, followed by a voltage vari-
able attenuator that is controlled via dip switches on the front panel (refer to table 1-1 and figure
4-1). The maximum composite input signal may not exceed +31dBm. The composite signal is
then fed to a two-way power splitter. The signals are applied to the amplifiers, and the amplifier
outputs are combined again (refer to Tables 1-2 through 1-7 for specifications). With both ampli-
fiers installed, the system provides 20dB of gain.
The BAS also houses a distribution printed circuit board (PCB) for internal power and alarm distri-
bution (refer to Appendix B). Accessible from the front panel is the DB9 external ALARM con-
nector, the RF IN and RF OUT type N connectors.
Additionally, the front panel provides access to the +27 Vdc POWER IN connector, visibility of the
two MCPA’s fault alarm LED indicators and the GAIN CTRL dip switch. Refer to table 1-1 for the
dip switch truth table and fiqure 1-1 for pin designations.
With the access door open, the two amplifier modules are visible. All solid-state, the MCPAs are
designed for parallel operation for high peak power output. Their modular construction and
unique and highly effective LED-based operational status and fault indicators help minimize
downtime. The turn-on and turn-off sequence of voltages are fully automatic, as is overload pro-
tection and recycling. Inadvertent operator damage from front panel manipulation is virtually im-
possible. Refer to Figures 1-7 and 1-8 for drawing views of the amplifier module.