Paradigm MAF800-100S User manual

REPORT RC055097/28116
APPENDIX A
SERVICE/OPERATING MANUAL

MAF800-100S
MULTI-CARRIER
POWER
AMPLIFIER
USER MANUAL

Table Of Contents
Page
Section 1 No.
General Description..............................................................................................................1
Section 2
Specifications........................................................................................................................2
Section 3
Multi-Carrier Power Amplifier Principals of Operation.......................................................3
Principals of Operation.........................................................................................................4
Principals of Operation.........................................................................................................5
Principals of Operation…………………………………………………….6
Section 4
Operating Instructions...........................................................................................................7
Operating Instructions………………………………………………………8
Section 5
Installation Instructions.........................................................................................................9
Installation Instructions........................................................................................................10
Installation Instructions........................................................................................................11
Section 6
Maintenance.........................................................................................................................12
Maintenance.........................................................................................................................13
Maintenance.........................................................................................................................14
Maintenance.........................................................................................................................15
Maintenance.........................................................................................................................16
Section 7
Troubleshooting……………………………………………………………17

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Section 1 Amplifier System Description
1.1Introduction
This manual contains information and procedures for installation, operation, and maintenance of Paradigm
Wireless Systems MAF800-100S multi-carrier cellular amplifier. This manual is organized into the
following sections:
Section 1. Amplifier System Description
Section 2. Specifications
Section 3. Principals of Operation
Section4. Operating Instructions
Section5. Installation
Section 6. Maintenance
Section 7. Troubleshooting
1.2 General Description
The MAF800-100S is a linear, feed forward power amplifier that operates in the 25 MHz frequency range
from 869 MHz to 894 MHz. The average output power of the amplifier is 100 Watts average AMPS,
CDMA, CDMA 2000, 1xEV-DO, GSM, TDMA, and EDGE. The amplifier is designed to operate ina
maximum of two continuous modulations or a total instantaneous bandwidthof 25 MHz. The amplifier can
simultaneously transmit multiple frequencies, with a better than –13 dBm third order intermodulation
distortion. The amplifier is designed and suited for use in CDMA, TDMA, EDGE and GSM radio base
stations. A sub-rack is employed to combine the outputs of up to (4) MAF800-100S amplifiers. Each plug-
in module operates in parallel to produce a high peak output power and fail safe redundancy for trouble free
operation with minimum maintenance. A multi-color LED detects when a fault condition has occurred
within the amplifier. The LED will turn fromGREEN to RED duringanamplifier fault condition.
Eachamplifier has a status connector thatallows the host system to monitor the amplifier module
performance. Monitoring of the amplifiers is done through the D-subminiature connector on the back of the
MAF800-100S amplifiers. The front panel of the MAF800-100S amplifier has an ON/OFF circuit breaker.
Primary +27 Vdc power for the MAF 800-100S amplifiers is provided through the sub-rack assembly.
The sub-rack contains the fan assembly for cooling each amplifier. Cooling fans are used to pull air through
the heat sinks. Air movement across the heat sinks dissipates the heat generated by the amplifiers. Constant
airflow ensures the amplifiers performance to specifications.
Section 2 MAF800-100S Electrical Specification
Parameter Specification
Frequency 869-894 MHz
RF Gain 58 dB
Gain Variation over Temperature 0.3 dB
Gain Flatness 0.5 dB
Intermodulation Distortion ≤-13 dBm

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Out of Band Spurious ≤-13 dBm
Input Power -4 dBm
Output Power 100 Watts
Modulation Type AMPS, CDMA, CDMA 2000, TDMA, EDGE, GSM, 1x
EV-DO
Operating Instantaneous Bandwidth 25 MHz
Input Return Loss ≥15 dB
Output Return Loss ≥15 dB
Output Protection Mismatched Protected
Duty Cycle Continuous
Vdc Input Power +27 Vdc
Operating Current 24 amps per amplifier
MAF800-100S Environmental Specifications:
Parameter Specification
Operating Temperature 0°C. to 50°C.
Storage Temperature -40°C. to + 80°C.
Operating Humidity 5%- 95% Relative Humidity (Non-condensing)
Storage Humidity 5%-95% Relative Humidity (Non-condensing)
RF Input / Output Connector D-Sub, Hybrid, Plug-in Type RF Connector: PKZ
26-0020 series straight plug (Phoenix Co.)
Status / Alarm / Control / DC Input Connector 21 Pin D-Subminiature Combo Connector
Dimensions
Weight
Section 3 Principals of Operation
3.1 Introduction
This section contains the functional description of the MAF800-100S multi-carrier power amplifier.
3.2 RFInput Signal
The maximumcomposite input power shall not exceed – 4 dBm. The reference source signal shall not
exceed the base station manufacture minimum requirements for intermodulation distortion. For proper loop
balance, the out of band components of the input signal shall not exceed –40 dBc. The input VSWR should
be 2:1 maximum
3.3 RFOutput Load
The load impedance should be equal to or better than 1.5:1 in the operating band for good power transfer to
the load. If the amplifier is operated into a filter, it will maintainits distortioncharacteristics outside the
signal band even if the VSWR is infinite. Provided the reflected power does not exceed one-watt. A
parasitic signal of less than one-watt incident on the output will not cause distortionat a higher level than
the normal forward distortion

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3.4 Amplifier Functional Description
The MAF800-100S amplifier is a linear, feed-forward power amplifier that operates in the 25 MHz
frequency band from 869 MHz -894 MHz. The amplifier is designed to operate in an instantaneous
bandwidth of 25 MHz. Each amplifier is a self-contained plug in module and is functionally independent of
the other amplifier module. The amplifier modules are designed for parallel operation to achieve high peak
power output, and for redundancy in unmanned remote locations. Each amplifier in the systemcan
simultaneously transmit multiple carrier frequencies, at an average total power output of 100 Watts, with
better than –13 dBm intermodulation distortion.
All phase and gain corrections are performed on the signal (s) in the individual amplifier module. Each
amplifier module has an alarm board that monitors the amplifier performance. If a failure or fault occurs in
the amplifier module a multi-color LED will change from GREEN to RED. This will be displayed onthe
front of the individual amplifier front panel.
3.5 MAF800-100S Amplifier Module
The amplifier module has an average output of 100 Watts power with intermodulation products suppressed
to better than -13 dBm. The amplifier provides an amplified output signal with constant gain and phase by
adding approximately 25 dB of distortion cancellation on the output signal. Continuously comparing active
paths with passive references, and correcting for small variations through RF feedback control maintain
constant gain and phase. The amplifier module is comprised of:
Preamplifiers
Main Amplifiers
Error Amplifier
Two feed-forward loops with phase–shift and gain controls
DC/DC power regulator
Alarm monitoring, control and LED display lamp

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MAF800-100S Block Diagram

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The main amplifier employs class AB amplification for maximum efficiency. The error amplifier and feed
forward loops are employed to correct signal non-linearity introduced by the class AB main amplifier. The
error amplifier operates in class AB mode. The RF input signals are amplified by a preamp and coupled to
an attenuator and phase shifted by 180 degrees and amplified in the pre-main amplifier. The output from
the pre-mainamplifier is fed to the class AB mainamplifier. The output fromthe mainamplifier is
typically 100 Watts.
The signal output fromthe mainamplifier is sampled usinga coupler. The sample signal is combined with
the main input signal and input to the second feed-forward loop. The error signal is attenuated, phase
shifted 180 degrees, then passed to the error amplifier where it is amplified to a level identical to the
sampled output from the mainamplifier. The output from the error amplifier is then coupled backand
added to the output from the main amplifier. The control loops continuously make adjustments to cancel
out any distortion in the final output signals.
The primary function of the 1st loop is to provide an error signal for the 2nd loop. The primary function of
the 2nd loop is to amplify the error signal to cancel out spurious products developed in the main amplifier.
The input signal is amplified bya pre-amplifier and fed to a coupler and delay line. The signal from the
coupler is fed to the attenuator and phase shifter in the 1st loop. The 1st loop control section phase shifts the
main input signals by 180 degrees and constantly monitors the output for correct phase and gain.
The 2nd loop control section obtains a sample of the distortion added to the output signals by the main
amplifiers, and then phase shifts the signals by 180 degrees then feeds the signal to the error amplifier.
There it is amplified to the same power level as the input sample and coupled on to the main output signal.
The final output is monitored by the 2nd loop and adjusted to ensure that the signal distortion and IMD on
the final output is cancelled.
3.6 Main Amplifier
The input and output of the amplifier employ two-stage, class AB amplifiers, which provide approximately
25 dB of gain in the 25 MHz frequency band, from 869 MHz to 894 MHz. The amplifier operates on +27
Vdc, and is mounted directly on a heat sink, which is temperature monitored by a thermal sensor. If the
heat sink temperature exceeds 85°C. a high temperature fault occurs. The alarmlogic controls the
transistor bias voltage; this shuts down the amplifier if bias voltage is out of range.

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3.7 Error Amplifier
The primary function of the error amplifier is to sample and amplify the signal distortion level generated by
the mainamplifier. The error amplifier cancels out the distortionand IMD whenthe error signal is coupled
onto the main signal at the amplifier output. The matching signal levels fromthe error amplifier are
injected back into the main amplifier output reducing any distortion and cancellation of IMD. The error
amplifier is a balanced multistage class AB amplifier. It has 75 dB of gain, and produces up to 65 Watt
output. The amplifier operates on +27 Vdc and is mounted directly on a heat sink.
3.8 Amplifier Status Monitoring
In the main and error amplifier stages, all normal variations are automatically compensated for by the feed-
forward loop control. When large variations occur beyond the adjustment range of the loop control, a loop
fault will occur. The amplifier will be disabled, and the LED will be RED. The alarms will be sent via the
21-pin connector on the rear of the module to the sub-rack summary alarm board.
3.9 Amplifier Module Cooling
Eachamplifier module has its own heat sinks. All mainamplifier components are mounted to the heat sink.
Forced air-cooling is used to pull air across the heat sinks for operations in the sub-rack. The fans for this
forced air-cooling is located in the sub-rack assembly. The fans are mounted in the rear of the sub-rack
assembly. Air is pulled from the front of the amplifier and exhausted out of the back of the rack.
3.10 DC Power Distribution
Primary Vdc for the systemis provided by the host system to the sub-rack assembly. The sub-rack supplies
the +27 Vdc to the amplifier module. The +27 Vdc is supplied directly through the sub-rack power
splitter/combiner board. The amplifier module has a DC/DC converter that converts the +27 Vdc to +12
Vdc, +5Vdc,
Section 4 Operating Instructions
4.1 Introduction
This section contains operating instructions for the MAF800-100S Cellular Amplifier System.
4.2 Function of Amplifier Module Controls
Primary +27 Vdc power for the MAF800-100S amplifiers is applied via the 50-amp circuit breaker on the
front panel of the amplifier. A reset switchis located below the LED on the front panel. This switch resets
the amplifier module in the event of a minor alarm. The front panel LED is a multi color LED that changes
from GREEN in normal operation to RED during major or AMBER during minor alarms.

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4.3 Alarm Definition
ALARM CATEGORY LED MCPA
MODULE MCPA DISABLE
SIGNAL
CONDITION
Over PWR Critical Red Disable High MCPA module output power
> 150 Watts
Over PWR Critical Red Disable High Input power > - 4 dBm
High TEMP Minor Red Enable Low High temperature detected
High TEMP Critical Red Disable High High temperature detected for longer
than two minutes
VSWR Minor Red Enable Low Reflected power detected at output >7.5
Watts
VSWR Critical Red Disable High Reflected power detected at output >26
Watts
DC Fail Minor Red Enable Low One of the internal DC voltages
dropped below or exceeded the safe
threshold level
DC Fail Critical Red Disable High Voltage out of range for longer than
approximately two minutes.
DC Fail
(Over
Voltage)
Minor Red Disable High +27 Vdc input >28 Vdetected
DC Fail
(Over
Voltage)
Critical Red Disable High +27 Vdc input >28 V. for longer than
one second after initial detectionof
Vdc input >28 V.
Loop Fail Minor Red Enabled Low Loop failure detected
Loop Fail Critical Red Disable High Loop failure detected longer than two
minutes.