Powerwave Technologies 5JS0051 Multi-Channel Cellular Amplidier User Manual SECTION 3

Powerwave Technologies Inc Multi-Channel Cellular Amplidier SECTION 3

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869-894 MHz044-05095 Rev. A February 2001Installation & Service ManualG3S-800-140Multi-Carrier Amplifier System869 – 894 MHz

G3S-800-140 Installation & Service Manual044-05095 Rev. A iFebruary 2001Table Of ContentsPar. Section 1 PageNo. General Description No.1-1 Introduction.........................................................................................................................1-11-2 General Description.........................................................................................................1-11-3 Functional And Physical Specifications.......................................................................1-11-4 Equipment Changes...........................................................................................................1-11-5 Ordering Information.........................................................................................................1-2Section 2Installation2-1 Introduction.........................................................................................................................2-12-2 Electrical Service Recommendations...........................................................................2-12-3 Unpacking and Inspection...............................................................................................2-12-4 Installation Instructions...................................................................................................2-22-5 Amplifier Module Connectors.........................................................................................2-22-5.1 Amplifier Module Status, Alarm, Control, and Power Connector............................2-32-5.2 Amplifier Module RF Connector......................................................................................2-4Section 3Operating Instructions3-1 Introduction.........................................................................................................................3-13-2 Location and Function of Amplifier Module Controls and Indicators.....................3-13-3 Initial Start-Up and Operating Procedures...................................................................3-4Section 4Principles of Operation4-1 Introduction.........................................................................................................................4-14-2 RF Input Signal....................................................................................................................4-14-3 RF Output Load....................................................................................................................4-14-4 G3S-800-140 Amplifier Module........................................................................................4-14-4.1 Main Amplifier....................................................................................................................4-24-4.2 Error Amplifier....................................................................................................................4-24-4.3 Amplifier Monitoring.........................................................................................................4-24-4.4 Amplifier Module Cooling................................................................................................4-34-4.5 Power Distribution ............................................................................................................4-34-4.6 Intermodulation..................................................................................................................4-34-4.7 Two Tone Intermodulation...............................................................................................4-34-4.8 Multitone Intermodulation...............................................................................................4-34-4.9 Alarms..................................................................................................................................4-3

G3S-800-140 Installation & Service Manual044-05095 Rev. A ii February 2001Section 5Maintenance5-1 Introduction.........................................................................................................................5-15-2 Periodic Maintenance......................................................................................................5-15-3 Test Equipment Required For Test..................................................................................5-15-4 Clean Air Inlets/Outlets....................................................................................................5-25-5 Performance Test...............................................................................................................5-25-5.1 Amplifier System Performance Test..............................................................................5-25-5.2 Amplifier IMD Test..............................................................................................................5.35-5.3 Gain Test..............................................................................................................................5-35-5.4 Harmonic Test.....................................................................................................................5-35-5.5 Spurious Emissions Test ..................................................................................................5-45-5.6 Input Return Loss................................................................................................................5-45-6 Field Replacement Parts and Modules.........................................................................5-65-6.1 G3S-800-140 Power Amplifier Module...........................................................................5-65-6.2 Cooling Fans........................................................................................................................5-6Section 6Troubleshooting6-1 Introduction.........................................................................................................................6-16-2 Troubleshooting.................................................................................................................6-16-3 Return for Service Procedures........................................................................................6-16-3.1 Obtaining an RMA..............................................................................................................6-16-3.2 Repackaging for Shipment...............................................................................................6-1List of IllustrationsFigureNo.1-1 G3S-800-140 Front and Side View...................................................................................1-32-1 G3S-800-140 Rear View.....................................................................................................2-22-2 DC and Logic Connector...................................................................................................2-32-3 Amplifier RF Connector.....................................................................................................2-43-1 G3S-800-140 Amplifier Module RF Control Indicators................................................3-14-1 G3S-800-140 Power Amplifier Module Functional Block Diagram..........................4-25-1 Amplifier System Test Setup Diagram...........................................................................5-3

G3S-800-140 Installation & Service Manual044-05095 Rev. A iii February 2001List Of TablesTableNo.1-1 Major Amplifier Components..........................................................................................1-21-2 G3S-800-140 MCPA Functional Specifications............................................................1-22-1 Amplifier Module DC and Logic Connector Definition...............................................2-32-2 Amplifier RF Connector Definition .................................................................................2-43-1 Amplifier Module RF Control and Indicators Definition............................................3-23-2 Amplifier Module Alarm Indicators Definition............................................................3-35-1 Periodic Maintenance......................................................................................................5-15-2 Test Equipment Required.................................................................................................5-25-3 MCPA Test Data Sheet......................................................................................................5-56-1 Troubleshooting.................................................................................................................6-1

G3S-800-140 Installation & Service Manual044-05095 Rev. A 1-1 February 2001Section 1 General Description1-1 IntroductionThis manual contains information and procedures for installation, operation, and maintenance ofPowerwave’s G3S-800-140 multicarrier cellular amplifier. The manual is organized into six sec-tions as follows:Section 1. General DescriptionSection 2. InstallationSection 3. Operating InstructionsSection 4. Principles of OperationSection 5. MaintenanceSection 6. Troubleshooting1-2 General DescriptionThe G3S-800-140 (see figure 1-1) is a linear, feed-forward power amplifier that operates in the 25MHz frequency band from 869 MHz to 894 MHz. The amplifier can simultaneously transmit multi-ple frequencies, with better than -60 dBc third order intermodulation distortion (IMD). It is de-signed for use in an amplifier system that is modular in design, and is ideally suited for use inAMPS/TDMA/CDMA/CDPD/W-CDMA base stations. The plug-in Model G3S-800-140 amplifiermodules can each provide 140 watts of power and function completely independently of eachother. The amplifier modules are designed for parallel operation to produce high peak power out-put and backup redundancy for remote applications. All solid-state, the system is designed toprovide trouble-free operation with minimum maintenance. The system's modular constructionand unique and highly effective LED-based operational status and fault indicators help minimizedowntime. The turn-on and turn-off sequences of voltages are fully automatic, as is overloadprotection and recycling. Inadvertent operator damage from front panel manipulation is virtuallyimpossible.The amplifier module has a status connector that allows the host system to monitor the amplifiermodule performance. The front panel of each amplifier module has unit level status/fault indica-tors and an RF on/off/reset switch. Primary power for the amplifier is +27 Vdc. Cooling for eachplug-in amplifier module is provided by four fans, two mounted on the front and two on the rear ofthe module. The fans draw outside air through the front of the module and exhaust hot air outthrough the rear of the module.1-3 Functional And Physical SpecificationsFunctional and physical specifications for the amplifier are listed in table 1-2.1-4 Equipment ChangesPowerwave Technologies, Inc. reserves the right to make minor changes to the equipment, in-cluding but not necessarily limited to component substitution and circuitry changes. Changes thatimpact this manual may subsequently be incorporated in a later revision of this manual.

G3S-800-140 Installation & Service Manual044-05095 Rev. A 1-2 February 20011-5 Ordering InformationTable 1-1 following gives the part numbers and descriptions to be used when ordering either anentire amplifier or replacement fans.Table 1-1 Major Amplifier ComponentsModel number DescriptionG3S-800-140 140 W 869-894 MHzMCPA Module.800-01075-003 Front fan assembly800-00972-002 Rear fan assembly.Table 1-2 G3S-800-140 Multicarrier Cellular Amplifier Functional SpecificationsFrequency Range 869-894 MHz (25 MHz Bandwidth)Total Maximum Input Power -6.0 dBmTotal Output Power 140 W typical (1 Module)Intermodulation Distortionand In-Band Spurious: -60 dBc (Max) @ +26 to +28 Vdc @ 140 Watts-60 dBc (Max) @ +24 to +26 Vdc @ 143 Watts-60 dBc (Max) @ +21.7 to +24 Vdc @ 100 WattsRF Gain at 880 MHz 58 dBGain Flatness: ± 0.5 dB @ 27 Vdc ±1 VdcGain Variation Over Voltage: ±0.5 dB from 26 to 28 VdcOutput Protection: Mismatch ProtectedInput Port Return Loss: -16 dB (Min)Second Harmonics: +5 dBm (Max)Out of Band Spurious: Better than -60 dBc, +26 to +28 VdcDuty Cycle: ContinuousDC Input Power: +27 Vdc ± 1 Vdc, 70 Amps Max @ 140 WattsOperational +21.7 to 30 VdcOperating Temperature: – 5°C to +50°CStorage Temperature: -40 ºC. to +85 ºC.Operating Humidity: 5 % - 95 % Relative Humidity (Noncondensing)Storage Humidity: 5 % - 95 % Relative Humidity (Noncondensing)RF Input / Output Connector BMA Coaxial Female, RadiallStatus / Alarm / Control / DC InputConnectors: 21-Pin D-Subminiature Combo ConnectorDimensions: 5.22” High, 17.00” Wide, 20.44” Deep (Including handles, rearfans)

G3S-800-140 Installation & Service Manual044-05095 Rev. A 1-3 February 2001Figure 1-1 G3S-800-140

G3S-800-140 Installation & Service Manual044-05095 Rev. A 2-1 February 2001Section 2 Installation2-1 IntroductionThis section contains installation recommendations, unpacking, inspection, and installation in-structions for the Multicarrier Cellular Amplifier. Carefully read all material in this section prior toequipment unpacking or installation. Also read and review the operating procedures in Section 3prior to installing the equipment. It is important that the licensee perform these tasks correctly andin good faith. If applicable, carefully review the Federal Communications Commission (FCC) rulesas they apply to your installation. DON'T TAKE CHANCES WITH YOUR LICENSE.2-2 Electrical Service RecommendationsPowerwave Technologies recommends that proper AC line conditioning and surge suppressionbe provided on the primary AC input to the +27 Vdc power source. All electrical service should beinstalled in accordance with the National Electrical Code, any applicable state or local codes, andgood engineering practice. Special consideration should be given to lightning protection of allsystems in view of the vulnerability of most transmitter sites to lightning. Lightning arrestors arerecommended in the service entrance. Straight, short ground runs are recommended. The elec-trical service must be well grounded.Each amplifier system should have its own circuit breaker, so a failure in one does not shut off thewhole installation. Circuit breakers should be capable of handling the anticipated inrush current,in a load center with a master switch.2-3 Unpacking And InspectionThis equipment has been operated, tested and calibrated at the factory. Only in the event of se-vere shocks or other mistreatment should any substantial readjustment be required. Carefullyopen the container(s) and remove the amplifier module(s). Retain all packing material that can bereassembled in the event that the unit must be returned to the factory.CAUTIONExercise care in handling equipment during inspection to prevent damage caused byrough or careless handling.Visually inspect the amplifier module for damage that may have occurred during shipment. Checkfor evidence of water damage, bent or warped chassis, loose screws or nuts, or extraneouspacking material in the connector or fans. Inspect the rear panel connector for bent connectorpins. If the equipment is damaged, a claim should be filed with the carrier once the extent of anydamage is assessed. We cannot stress too strongly the importance of IMMEDIATE careful in-spection of the equipment and the subsequent IMMEDIATE filing of the necessary claims againstthe carrier if necessary. If possible, inspect the equipment in the presence of the delivery person.If the equipment is damaged, the carrier is your first area of recourse. If the equipment is dam-aged and must be returned to the factory, write or phone for a return authorization. Powerwavemay not accept returns without a return authorization. Claims for loss or damage may not bewithheld from any payment to Powerwave, nor may any payment due be withheld pending theoutcome thereof. WE CANNOT GUARANTEE THE FREIGHT CARRIER'S PERFORMANCE.

G3S-800-140 Installation & Service Manual044-05095 Rev. A 2-2 February 20012-4 Installation Instructions (refer to figures 1-1 and 2-1)The G3S-800-140 amplifier module is designed for installation in a subrack that permits access tothe rear of the subrack for connection of DC power, RF, and monitor cables.To install the amplifier proceed as follows:1. Install subrack in equipment rack and secure in place.2. Connect antenna cable to rear of subrack.3. Connect the transceiver output(s) to rear of subrack.4. Connect alarms cable(s).WARNINGVerify that all circuit breaker switches on the rear panel of the subrack are in the OFFposition. Turn off external primary DC power before connecting DC power cables.5. Connect positive primary power and negative primary power to the subrack. Tighten thesubrack power connections.6. Install the plug-in amplifier module(s) in the subrack. Tighten left and right thumbscrews.7. Check your work before applying DC voltage to the system. Make certain all connections aretight and correct.8. Measure primary DC input voltage. DC input voltage should be +27 Vdc ±1.0 Vdc. If the DCinput voltage is above or below the limits, call and consult Powerwave before you turn onyour amplifier system.9. Refer to section 3 for initial turn-on and checkout procedures.2-5 Amplifier Module ConnectorsThe amplifier has three connectors on the right rear of the module. The larger is a 21-pin maleD-Sub combo which provides the status, alarm, control, and power connections. The smallerBMA coaxial female connectors provide the RF connections. Refer to figure 2-1.Figure 2-1 G3S-800-140 Amplifier, Rear View

G3S-800-140 Installation & Service Manual044-05095 Rev. A 2-3 February 20012-5.1 Amplifier Module Status, Alarm, Control, And Power ConnectorThe amplifier has a separate remote alarm and control connector which may be used by the hostsystem to monitor and control the individual amplifier modules. The status, alarm, control, andpower connections on the amplifier connector are made through a 21-pin male D-Sub comboconnector (figure 2-2) and are listed and described in table 2-1.A1 A2 A3 A41 2 3 4 5 6 7 8 910 11 12 13 14 15 16 17Figure 2-2 DC and Logic Connector (on Rear of G3S-800-140 Amplifier Module)Table 2-1 Amplifier Module DC and Logic Connector DefinitionPin Function DescriptionA1 Power Input +27 Vdc (Power Contact)A2 Power Input +27 Vdc (Power Contact)A3 Ground Ground (Power Contact)A4 Ground Ground (Power Contact)1 RS485 +TxD Serial Communication Data Out2 RS485 +RxD Serial Communication Data In3 Service Loop TTL input to Amp. Gnd. for special test mode (Note 1)4 MCPA Disabled(Summary Fault) TTL signal normally low indicates MCPA enabled. A high level indi-cates that the MCPA has been disabled. Over Power, Over Voltagetakes one second to activate the signal.5 Mod Addr 0 TTL input to Amp. Gnd. supplied by shelf to identify slot.6 Mod Addr 1 TTL input to Amp. Gnd. supplied by shelf to identify slot.7 TP1 TTL output. Future test point.8 Manual Download GND to download manually9 DC on stat TTL output. High indicates Amp is powered on.10 RS485 –TxD Serial Communication Data Out11 RS485 –RxD Serial Communication Data In12 SCL7 No connection13 SDA7 No connection14 FP Disable Output Output, GND if the front panel switch is in the OFF position; +5 voltsindicates the front panel switch is in the ON position.15 FP RST Output, GND if the front panel switch is in the RESET position; +5 voltsotherwise.16 GND Ground17 Module Detect Ground potential. Informs the subrack that an MCPA is plugged in.Note 1: Service loop grounded allows the MCPA to be enabled or disabled by the front panelswitch when not mounted in the shelf.

G3S-800-140 Installation & Service Manual044-05095 Rev. A 2-4 February 20012-5.2 Amplifier Module RF ConnectorThe amplifier has a separate RF connector which is used for the RF signal input and output. TheRF connections on the amplifier connector are made through two BMA female coaxial connectors(figure 2-3) and are listed and described in table 2-2.Figure 2-3 Amplifier RF ConnectorTable 2-2 Amplifier RF Connector DefinitionPin Function DescriptionA1 RF Input BMA Coaxial Female, RadiallA2 RF Output BMA Coaxial Female, RadiallA1 A2

G3S-800-140 Installation & Service Manual044-05095 Rev. A 3-1 February 2001Section 3 Operating Instructions3-1 IntroductionThis section contains operating instructions for the Multicarrier Cellular Amplifier System.3-2 Location And Function Of Amplifier Module Controls And IndicatorsPrimary +27 Vdc power is applied to the amplifier via a 100-amp circuit breaker (ON-OFF) locatedon the left side of the amplifier front panel.The plug-in amplifier module RF control and indicators, located in the center of the amplifier frontpanel between the cooling fans, are shown in figure 3-1. The status and RF control functions aredescribed in detail in table 3-1. The alarms are described in detail in table 3-2.Figure 3-1 G3S-800-140 Amplifier Module RF Control and Indicators

G3S-800-140 Installation & Service Manual044-05095 Rev. A 3-2 February 2001Table 3-1 Amplifier Module RF Control and Indicators DefinitionName Function (Note: MCPA = Multicarrier Power Amplifier)+27VDCIndicatorGreen LED. When lit, indicates that the +27 Vdc supply is greater than +21 Vdcand less than +31 Vdc. If the +27 Vdc indicator goes out, the DC FAIL indicatorwill illuminate. This indicates that the +27 Vdc voltage dropped below +21 Vdc.+15VDCIndicatorGreen LED. When lit, indicates that the +15 Vdc supply is greater than +12 Vdcand less than +17 Vdc. If the +15 Vdc indicator goes out, the DC FAIL indicatorwill illuminate. This indicates that the +15 Vdc voltage dropped below +12 Vdc orincreased above +17 Vdc.+5VDCIndicator Green LED. When lit, indicates that the +5 Vdc supply is greater than +2 Vdc andless than +7 Vdc. If the +5 Vdc indicator goes out, the DC FAIL indicator will illu-minate. This indicates that the +5 Vdc voltage dropped below +2 Vdc or in-creased above +7 Vdc.-5VDCIndicator Green LED. When lit, indicates that the -5 Vdc supply is greater than -7 Vdc andless than -2 Vdc. If the -5 Vdc indicator goes out, the DC FAIL indicator will illumi-nate. This indicates that the -5 Vdc voltage dropped below -7 Vdc or increasedabove -2 Vdc.RF ONSwitch Three position switch:Off (down position) - Turns off amplifier module.On (center position) - Normal amplifier on position.Reset (up position) - When toggled to reset position, all the red LED indicators willturn on one at a time in sequence followed by all the green indicators one at atime in sequence; this will also reset the fault latches. If the switch is held in thereset position, a microcontroller reset will occur. This will be verified by the LEDstoggling state again. The switch is spring loaded to return to the normal ON posi-tion when released. If a fault occurs and the MCPA is disabled, the alarms can becleared and the MCPA enabled by this reset position. The functions of the switchare disabled for five seconds after a power-up condition.

G3S-800-140 Installation & Service Manual044-05095 Rev. A 3-3 February 2001A ‘Minor Alarm’ will flag a potential fatal problem by the LEDs and the MCPA fault will be inevaluation. A ‘Critical Alarm’ is indicative of a fatal problem. The fault indicator will latch on andthe MCPA module will be disabled. A ‘Major Alarm’ indicates a major problem but the MCPAmodule will not be disabled. Both ‘Major Alarm’ and ‘Critical Alarm’ will be sent to the host systemvia the MCPA subrack.Table 3-2 Amplifier Module Alarm Indicators DefinitionAlarm Mode LED MCPAModuleMCPADisable signal(pin 4 inTable 2-1) ConditionOver Pwr Critical Red Disable High MCPA module output power >200watts (Note 4)Over Pwr Critical Red Disable High Input power >-2 dBmHigh Temp Minor Red Enable Low High temperature detectedHigh Temp Critical Red Disable High High temperature detected for longerthan two minutesVSWR Minor Red Enable Low 14.5 W < Reflected Power < 38WVSWR Critical Red Disable High 60W < Reflected power detected atoutput longer than approx. two min.DC Fail Minor Red Enable Low One of the internal DC voltagesdropped below or exceeded the safethreshold levelDC Fail Critical Red Disable High Voltage out of range for longer thanapprox. two minutes (Note 2)DC Fail(Overvoltage) Critical Red Disable High +27 Vdc input >30 V for longer thanone sec. after initial detection of DCinput >31 V (Note 3)Fan Fail(one) Major Red Enable Low Any fan failureLoop Fail Minor Red Enable Low Loop failure detectedLoop Fail Critical Red Disable High Loop failure detected longer than 2minutesLow Pwr Minor Red Enable Low Rack controller detected MCPA out-put is 3 dB below that of the otherMCPA in the system.Low Pwr Critical Red Disable High Rack controller detected low powercondition for more than approx. twominutesLPADISAB. Critical Red Disable HighUnit is manually switched off usingthe front panel RF ON switch, or dis-abled by a serial command or autoshutdown by an alarm condition.NOTES:1. RS-485 serial alarm will follow LED status.2. The appropriate status LED shall turn off indicating which voltage is out of its range.3. When overvoltage is detected:a) MCPA shall shut down (disable)b) Turn on red DC Fail LEDc) Set flag for DC Fail alarm4. When overpower is detected:a) MCPA shall shut down (disable)b) Turn on Over Pwr LEDc) Set flag for Over Pwr alarmd) The MCPA module shall use a peak power detector to determine the overpower fault.

G3S-800-140 Installation & Service Manual044-05095 Rev. A 3-4 February 20013-3 Initial Start-Up And Operating ProceduresThe amplifier module has two operating controls, both located on the front face of the module: thepower ON - OFF switch and the RF ON - ON/OFF/RESET switch. To perform the initial start-up,proceed as follows:1. Double check to ensure that all input and output cables are properly connected.CAUTIONBefore applying power, make sure that the input and output of the amplifier areproperly terminated at 50 ohms. Do not operate the amplifier without a load attached.Refer to table 1-2 for input power requirements. Excessive input power may damagethe amplifierNOTEThe output coaxial cable between the amplifier and the antenna must be 50 ohm coaxialcable. Use of any other cable will distort the output.2. Verify that the amplifier front panel switches are in the OFF position.3. Turn on supply that provides +27 Vdc to the amplifier system. Do not apply an RF signal tothe amplifier system4. Place the ON - OFF circuit breaker on the amplifier in the ON position. Visually check theindicators on the amplifier module, and verify that the following indicators are on:A. LPA DISAB. indicator (red) should be on.B. The +27VDC, +15VDC, +5VDC and -5VDC indicators (green) on the amplifier moduleshould be on.5. Set the RF ON switch to the ON (center) position. All red LEDs should turn off after six sec-onds.6. Turn on external exciter/transceiver and apply RF input signals.

G3S-800-140 Installation & Service Manual044-05095 Rev. A 4-1 February 2001Section 4 Principles of Operation4-1 IntroductionThis section contains a functional description of the Multicarrier Cellular Amplifier.4-2 RF Input SignalThe maximum input power for all carrier frequencies should not exceed the limits specified in ta-ble 1-2. For proper amplifier loop balance, the out of band components of the input signals shouldnot exceed -40 dBc. The input VSWR should be 2:1 maximum (or better).4-3 RF Output LoadThe load impedance should be as good as possible (1.5:1 or better) in the working band for goodpower transfer to the load. If the amplifier is operated into a filter, it will maintain its distortioncharacteristics outside the signal band even if the VSWR is infinite, provided the reflected powerdoes not exceed one watt. A parasitic signal of less than one watt incident on the output will notcause distortion at a higher level than the normal forward distortion (i.e. -60 dBc).4-4 G3S-800-140 Amplifier ModuleThe G3S-800-140 amplifier is a linear, feed-forward power amplifier that operates in the 25 MHzfrequency band from 869 MHz to 894 MHz. The amplifier modules are designed for parallel op-eration to achieve high peak power output, and for redundancy in unmanned remote locations.The amplifier module, figure 4-1, has an average output of 140 watts power (1400 watts peakpower) with intermodulation products suppressed to better than -60 dBc below carrier levels. Theamplifier provides an amplified output signal with constant gain and phase by adding approxi-mately 30 dB of distortion cancellation on the output signal. Constant gain and phase is main-tained by continuously comparing active paths with passive references, and correcting for smallvariations through the RF feedback controls. All gain and phase variations, for example thosedue to temperature, are reduced to the passive reference variations. Each amplifier module hasan alarm and display board that monitors the amplifier performance. If a failure or fault occurs inan amplifier module, it is displayed on the individual amplifier front panel.The amplifier module is comprised of:Pre-amplifiersMain amplifierError amplifierTwo feed-forward loops with phase-shift and gain controlsDC/DC power regulatorAlarm monitoring, control and display panelThe main amplifier employs class AB amplification for maximum efficiency. The error amplifierand feed forward loops are employed to correct signal nonlinearities introduced by the class ABmain amplifier. The error amplifier operates in class AB mode. The RF input signals are ampli-fied by a preamp and coupled to an attenuator and phase shifter in the first feed-forward loop.The main signal is phase shifted by 180 degrees and amplified in the premain amplifier. The out-put from the premain amplifier is fed to the class AB main amplifier. The output from the mainamplifier is typically 220 watts. The signal is output to several couplers and a delay line.The signal output from the main amplifier is sampled using a coupler, and the sample signal iscombined with the main input signal and input to the second feed-forward loop. The error signal is

G3S-800-140 Installation & Service Manual044-05095 Rev. A 4-2 February 2001attenuated, phase shifted 180 degrees, then fed to the error amplifier where it is amplified to alevel identical to the sampled output from the main amplifier. The output from the error amplifieris then coupled back and added to the output from the main amplifier. The control loops continu-ously make adjustments to cancel out any distortion in the final output signals.PreAmpPreMain MainAmpErrorAmpDelayFeed Forward Loop control2nd LoopPhase & Gain1st LoopPhase & Gain DelayAlarms & Display+15 +5 -5Power Supply-30dB -10dBRF OutRFLPWRFWDPWRFront PanelSmart Rack+27VDCFigure 4-1 G3S-800-140 Power Amplifier Module Functional Block DiagramThe 2nd loop control section obtains a sample of the distortion added to the output signals by themain amplifiers, phase shifts the signals by 180 degrees, then feeds it to the error amplifier.There it is amplified to the same power level as the input sample and coupled on to the main out-put signal. The final output is monitored by the 2nd loop and adjusted to ensure that the signaldistortion and IMD on the final output is canceled out.4-4.1 Main AmplifierThe input and output of the amplifier employ two-stage, class AB amplifiers which provide ap-proximately 32 dB of gain in the 25 MHz frequency band from 869 to 894 MHz. The amplifier op-erates on +27 Vdc, and a bias voltage of +5 Vdc, and is mounted directly on a heat sink which istemperature monitored by a thermostat. If the heat sink temperature exceeds 85 °C, the thermo-stat opens and a high temperature fault occurs. The alarm logic controls the +5 Vdc bias voltagewhich shuts down the amplifier.4-4.2 Error AmplifierThe main function of the error amplifier is to sample and amplify the signal distortion level gener-ated by the main amplifier, to a level that cancels out the distortion and IMD when the error signalis coupled onto the main signal at the amplifier output. The error amplifier is a balanced multi-stage, class AB amplifier, has 51 dB of gain, and produces up to an 80-watt output. The amplifieroperates on 27 Vdc and a bias voltage of +5 Vdc, and is mounted directly on a heat sink.4-4.3 Amplifier MonitoringIn the main and error amplifier modules, all normal variations are automatically compensated forby the feedforward loop control. However, when large variations occur beyond the adjustmentrange of the loop control, a loop fault will occur. The alarms are displayed on the front panel indi-cators and output via a 21-pin connector on the rear of the module to the subrack summary boardfor subsequent remote monitoring via the ALARMS connector. Refer to paragraph 2-5 as well asfigure 2-2 and table 2-2 for a description of the ALARMS connector.

G3S-800-140 Installation & Service Manual044-05095 Rev. A 4-3 February 20014-4.4 Amplifier Module CoolingAlthough each amplifier module contains its own heat sink, it is cooled with forced air. Four fansare used for forced air cooling and redundancy. The fans, located on the front and rear of theamplifier module, draw air in through the front of the amplifier and exhaust hot air out the back ofthe module. The fans are field replaceable.4-5 Power DistributionPrimary DC power for the system is provided by the host system to the MCR30830-1-3 Seriessubrack. The subrack supplies each amplifier module with +27 Vdc directly and via the RF powersplitter/combiner. The amplifier module has a DC/DC converter that converts the +27 Vdc to +15Vdc, +5 Vdc and -5 Vdc.4-6 IntermodulationThe G3S-800-140 amplifier is designed to deliver a 140-watt composite average power, multicar-rier signal, occupying a bandwidth less than or equal to 25 MHz, in the bandwidth from 869 to 894MHz. The maximum average power for linear operation, and thus the amplifier efficiency, will de-pend on the type of signal amplified.4-6.1 Two Tone IntermodulationWhen measured with two equal CW tones spaced anywhere from 30 kHz to 20 MHz apart, and atany power level up to the average power, the third order intermodulation products will be below-60 dBc4-6.2 Multitone IntermodulationAdding more tones to the signal will lower individual intermodulation products. If the frequenciesare not equally spaced, the level of intermodulation products gets very low. When the frequenciesare equally spaced, those products fall on top of each other on the same frequency grid. The av-erage power of all intermodulation beats falling on the same frequency is called the composite in-termodulation; it is -60 dBc or better.4-7 AlarmsThe presence of several plug-in amplifier alarms can be detected at the DC and logic connectoron the amplifier rear panel. Refer to table 2-1 and figure 2-2 for a description of the connector.

G3S-800-140 Installation & Service Manual044-05095 Rev. A 5-1 February 2001Section 5 Maintenance5-1 IntroductionThis section contains periodic maintenance and performance test procedures for the MulticarrierCellular Amplifier. It also contains a list of test equipment required to perform the identified tasks.NOTECheck your sales order and equipment warranty before attempting to service or repairthe unit. Do not break the seals on equipment under warranty or the warranty will benull and void. Do not return equipment for warranty or repair service until propershipping instructions are received from the factory.5-2 Periodic MaintenancePeriodic maintenance requirements are listed in table 5-1. Table 5-1 also lists the intervals atwhich the tasks should be performed.WARNINGWear proper eye protection to avoid eye injury when using compressed air.Table 5-1 Periodic MaintenanceTask Interval ActionCleaningAir Vents 30 Days Inspect and clean per paragraph 5-4InspectionCables and Connec-tors 12 Months Inspect signal and power cables forfrayed insulation. Check RF connectorsto be sure that they are tight.Performance Tests 12 Months Perform annual test per paragraph 5-5.5-3 Test Equipment Required For TestTest equipment required to test the amplifier system is listed in table 5-2. Equivalent test equip-ment may be substituted for any item, keeping in mind that a thermistor type power meter is re-quired.NOTEAll RF test equipment must be calibrated to 0.05 dB resolution. Any deviation from thenominal attenuation must be accounted for and factored into all output readings.

G3S-800-140 Installation & Service Manual044-05095 Rev. A 5-2 February 2001Table 5-2 Test Equipment RequiredNomenclature Manufacturer ModelSignal Generator RDL IMD-801D-03A30 dB Attenuator, 500 Watt Weinschel Corp. 53-30-3420 dB Attenuator, 20 Watt(2 each) TenulineSpectrum Analyzer H.P. 8560ECoax Directional Coupler H.P. 778DPower Meter/Sensor H.P. 437B/8481ANetwork Analyzer H.P. 8753CCurrent Probe5-4 Cleaning Air Inlets/OutletsThe air inlets and outlets should be cleaned every 30 days. If the equipment is operated in a se-vere dust environment, they should be cleaned more often as necessary. Turn off DC powersource before removing fans. If dust and dirt are allowed to accumulate, the cooling efficiencymay be diminished. Using either compressed air or a brush with soft bristles, loosen and removeaccumulated dust and dirt from the air inlet panels.5-5 Performance TestPerformance testing should be conducted every 12 months to ensure that the amplifier systemmeets the operational specifications listed in table 5-3. Also verify system performance after anyamplifier module is replaced in the field. The test equipment required to perform the testing islisted in table 5-2, and the test setup is shown in figure 5-1.NOTEThe frequencies used in this test are typical for an amplifier with a 25 MHz band from869 MHz to 894 MHz. Select evenly spaced F1, F2, F3, and F4 frequencies that cover theinstantaneous bandwidth of your system.5-5.1 Amplifier System Performance TestThis test is applicable to the G3S-800-140 amplifier modules. To perform the test, proceed asfollows:1. Connect test equipment to the amplifier as shown in figure 5-1.NOTEDo not apply any RF signals at this time.Turn on signal generator and set frequency F1 to 880 MHz, F2 to 883 MHz, F3 to 886 MHz,and F4 to 889 MHz. Adjust each signal generator output so that the sum power output fromall four signal generators equals -6 dBm at the input.

G3S-800-140 Installation & Service Manual044-05095 Rev. A 5-3 February 2001Figure 5-1 Amplifier System Test Setup Diagram5-5.2 Amplifier IMD Test And Current Test2. Adjust attenuator for an input signal at -10 dBm. Turn on the amplifier by setting RF ONswitch of amplifier. Adjust variable attenuator to set amplifier power output on power meter to140 watts. Measure IMD on spectrum analyzer. IMD should be -60 dBc max. Record testdata in table 5-3. Set RF ON switch to OFF.3. With the amplifier module set at 140 watts power output, use the current probe (magneticfield type) and measure the dc current flow from the +27 Vdc power source. Current shouldbe 70 amps maximum. Record test data in table 5-3.5-5.3 Gain Test4. Disconnect spectrum analyzer from test setup, and connect the network analyzer.5. Set network analyzer as follows:Ø Power output to -10 dBm.Ø Frequency start to 869 MHz.Ø Frequency stop to 894 MHz.Ø Normalize the network analyzer for gain and return loss.6. Check the gain across the band from 869 MHz to 894 MHz. Gain should be between 58 dB.Record test data in table 5-3.5-5.4 Harmonics Test7. 10.With the power set at 140 watts power output, use the spectrum analyzer and check thefrequency band from 869 MHz to 894 MHz for harmonics. Harmonics should be 5 dBmmaximum. Record test data in table 5-3.Unit Under TestG3S-800-140Plug-inAmplifier Module+27 VdcGnd RF InRFOut20 dBDirectionl Coupler30 dBAttenuator500 W20 dBAttenuator20 W Power MeterSensor Head8482A20 dBAttenuator20 WDirectionlCouplerPower MeterSensor Head8482ANetwork Analyzer8753CSignalGeneratorFilter /Isotlator10 dBVariableAttenuatorSpectrum Analyzer8651E

G3S-800-140 Installation & Service Manual044-05095 Rev. A 5-4 February 20015-5.5 Spurious Test8. With the power amplifier set at 140 watts power output, use the spectrum analyzer and checkthe frequency band from 869 MHz to 894 MHz for spurious signals. Spurious signals shouldbe -60 dBc maximum. Record test data in table 5-3.5-5.6 Input Return Loss Test9. Reset and turn on amplifier module. Read and record the S11 return loss measurement onnetwork analyzer. Input return loss should be –16 dB maximum. Record test data in table5-3.

G3S-800-140 Installation & Service Manual044-05095 Rev. A 5-5 February 2001Table 5-3 Multicarrier Cellular Amplifier Test Data SheetDATE _________________________________AMPLIFIER S/N _________________________TEST CONDITIONS:Load and Source Impedance: 50 OhmsVSWR: < 1.2:1Supply Voltage: +27 Vdc ±1.0 VdcTEST SPECIFICATION MIN MAX DATA4-TONE IMD Vcc = 27 VdcPO = 140 WFreq.: 880, 883, 886, and 889MHz-60 dBcRF Gain Vcc = 27 VdcPO = 140 WFreq. = 880 MHz 57.5 dB 58.5 dBGain Flatness Vcc = 27 Vdc ±1 VdcPO =140 W869-894 MHz Band -0.5 dB +0.5 dBHarmonics Vcc = 27 VdcPO = 140 W869-894 MHz Band 5 dBmSpurious Vcc = 27 VdcPO =140 W869-894 MHz Band -60 dBcInput ReturnLossVcc = 27 VdcPO = 140 W869-894 MHz Band -16 dBDC Power Vcc = 27 VdcPO = 140 W4 Tones 70 AmpsPASS _________________________________ FAIL _______________________________Tested by ______________________________

G3S-800-140 Installation & Service Manual044-05095 Rev. A 5-6 February 20015-6 Field Replaceable Parts And ModulesThe following parts and modules can be replaced in the field on site by a qualified technician withexperience maintaining RF power amplifiers and similar equipment:1. G3S-800-140 power amplifier modules2. Cooling fans5-6.1 G3S-800-140 Power Amplifier ModuleTo replace a power amplifier module, proceed as follows:1. Set both the RF ON On/Off/Reset switch and the power ON/OFF switch on the front panel ofthe amplifier module to OFF.2. Loosen two screws that secure amplifier module to subrack.3. Use handle on front of module, and with a steady even pressure, pull module out of subrack.CAUTIONWhen removing the amplifier from the subrack, it is very important to support theamplifier such that the rear of the module does not suddenly drop when it disengagesfrom the track. A drop such as this could damage the module.5-6.2 Cooling FansTo replace a cooling fan, proceed as follows:1. Remove amplifier module from subrack; see paragraph 5-6.1 preceding.2. Loosen four snap fasteners that secure fan to amplifier module. Disconnect fan power con-nector from amplifier module.Install replacement in reverse order of steps 1 and 2 above.

G3S-800-140 Installation & Service Manual044-05095 Rev. A 6-1 February 2001Section 6 Troubleshooting6-1 IntroductionThis section contains a list of problems which users have encountered and a few suggested ac-tions that may correct the problem. If the suggested corrective action does not eliminate theproblem, please contact your Powerwave field representative or the factory for further instructions.NOTECheck your sales order and equipment warranty before attempting to service or repairthe unit. Do not break the seals on equipment under warranty or the warranty will benull and void. Do not return equipment for warranty or repair service until propershipping instructions are received from the factory.6-2 TroubleshootingRefer to table 6-1 for troubleshooting suggestions.Table 6-1 Troubleshooting.Symptom Suggested ActionAny voltage indicators (green)are not lit or blinking1. Check that subrack power connection is secure.2. Check for proper power supply voltage.3. Check fuses or circuit breakers on amplifier or subrack.4. Verify that amplifier is fully inserted into subrack.HIGH TEMP alarm (red) is lit 1. Verify fan(s) are operating properly.2. Check ambient temperature (not to exceed spec – see ta-ble 1-2).OVER PWR alarm (red) is lit Verify RF input level does not exceed spec – see table 1-2.VSWR alarm (red) is lit Check output connections and cables for integrity and tight-ness.LOW PWR alarm (red) is lit Contact Powerwave field representative or factory.6-3 Return for Service ProceduresWhen returning products to Powerwave, the following procedures will ensure optimum response.6-3.1 Obtaining an RMAA Return Material Authorization (RMA) number must be obtained prior to returning equipment tothe factory for service. Please contact our Repair Department at (714) 466-1000 to obtain thisnumber, or FAX your request to (714) 466-5800. Failure to obtain this RMA number may result indelays in receiving repair service.6-3.2 Repackaging for ShipmentTo ensure safe shipment of the amplifier, it is recommended that the package designed for theamplifier be used. The original packaging material is reusable. If it is not available, contact ourRepair Department for packing materials and information.