Powerwave Technologies 5JS0051 Multi-Channel Cellular Amplidier User Manual SECTION 3
Powerwave Technologies Inc Multi-Channel Cellular Amplidier SECTION 3
User Manual
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| Document ID | 142789 |
| Application ID | 5+3jfBjC25uYW/0KeKVRWQ== |
| Document Description | User Manual |
| Short Term Confidential | No |
| Permanent Confidential | No |
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| Document Type | User Manual |
| Display Format | Adobe Acrobat PDF - pdf |
| Filesize | 16.92kB (211447 bits) |
| Date Submitted | 2001-03-30 00:00:00 |
| Date Available | 2001-03-30 00:00:00 |
| Creation Date | 2001-03-29 14:21:23 |
| Producing Software | Acrobat Distiller 4.05 for Windows |
| Document Lastmod | 2001-03-29 14:23:52 |
| Document Title | SECTION 3 |
| Document Creator | Microsoft Word 8.0 |
| Document Author: | Steve Ault |
869-894 MHz Installation & Service Manual G3S-800-140 Multi-Carrier Amplifier System 869 – 894 MHz 044-05095 Rev. A February 2001 G3S-800-140 Installation & Service Manual © 2001 Powerwave Technologies Incorporated. All rights reserved. Powerwave Technologies, and the Powerwave logo are registered trademarks Powerwave Technologies, Inc. reserves the right to make changes to the documentation and equipment, including but not limited to component substitution and circuitry changes. Changes that impact this manual may subsequently be incorporated in a later revision of this manual. February 2001 Powerwave Technologies, Inc. 1801 E. St. Andrew Place Santa Ana, CA 92705 044-05095 Rev. A Tel: (714) 466-1000 Fax: (714) 466-5800 Web Site: www.powerwave.com ii G3S-800-140 Installation & Service Manual Table Of Contents Par. No. 1-1 1-2 1-3 1-4 1-5 Section 1 General Description Page No. Introduction......................................................................................................................... 1-1 General Description ......................................................................................................... 1-1 Functional And Physical Specifications....................................................................... 1-1 Equipment Changes........................................................................................................... 1-1 Ordering Information ......................................................................................................... 1-2 Section 2 Installation 2-1 2-2 2-3 2-4 2-5 2-5.1 2-5.2 Introduction......................................................................................................................... 2-1 Electrical Service Recommendations ........................................................................... 2-1 Unpacking and Inspection ............................................................................................... 2-1 Installation Instructions ................................................................................................... 2-2 Amplifier Module Connectors ......................................................................................... 2-2 Amplifier Module Status, Alarm, Control, and Power Connector............................ 2-3 Amplifier Module RF Connector...................................................................................... 2-4 Section 3 Operating Instructions 3-1 3-2 3-3 Introduction......................................................................................................................... 3-1 Location and Function of Amplifier Module Controls and Indicators..................... 3-1 Initial Start-Up and Operating Procedures................................................................... 3-4 Section 4 Principles of Operation 4-1 4-2 4-3 4-4 4-4.1 4-4.2 4-4.3 4-4.4 4-4.5 4-4.6 4-4.7 4-4.8 4-4.9 Introduction......................................................................................................................... 4-1 RF Input Signal.................................................................................................................... 4-1 RF Output Load.................................................................................................................... 4-1 G3S-800-140 Amplifier Module........................................................................................ 4-1 Main Amplifier.................................................................................................................... 4-2 Error Amplifier .................................................................................................................... 4-2 Amplifier Monitoring......................................................................................................... 4-2 Amplifier Module Cooling................................................................................................ 4-3 Power Distribution ............................................................................................................ 4-3 Intermodulation .................................................................................................................. 4-3 Two Tone Intermodulation............................................................................................... 4-3 Multitone Intermodulation ............................................................................................... 4-3 Alarms .................................................................................................................................. 4-3 044-05095 Rev. A February 2001 G3S-800-140 Installation & Service Manual Section 5 Maintenance 5-1 5-2 5-3 5-4 5-5 5-5.1 5-5.2 5-5.3 5-5.4 5-5.5 5-5.6 5-6 5-6.1 5-6.2 Introduction......................................................................................................................... 5-1 Periodic Maintenance ...................................................................................................... 5-1 Test Equipment Required For Test.................................................................................. 5-1 Clean Air Inlets/Outlets .................................................................................................... 5-2 Performance Test............................................................................................................... 5-2 Amplifier System Performance Test .............................................................................. 5-2 Amplifier IMD Test..............................................................................................................5.3 Gain Test.............................................................................................................................. 5-3 Harmonic Test..................................................................................................................... 5-3 Spurious Emissions Test .................................................................................................. 5-4 Input Return Loss................................................................................................................ 5-4 Field Replacement Parts and Modules ......................................................................... 5-6 G3S-800-140 Power Amplifier Module........................................................................... 5-6 Cooling Fans........................................................................................................................ 5-6 Section 6 Troubleshooting 6-1 6-2 6-3 6-3.1 6-3.2 Introduction......................................................................................................................... 6-1 Troubleshooting ................................................................................................................. 6-1 Return for Service Procedures........................................................................................ 6-1 Obtaining an RMA.............................................................................................................. 6-1 Repackaging for Shipment............................................................................................... 6-1 List of Illustrations Figure No. 1-1 2-1 2-2 2-3 3-1 4-1 5-1 G3S-800-140 Front and Side View................................................................................... 1-3 G3S-800-140 Rear View..................................................................................................... 2-2 DC and Logic Connector ................................................................................................... 2-3 Amplifier RF Connector..................................................................................................... 2-4 G3S-800-140 Amplifier Module RF Control Indicators ................................................ 3-1 G3S-800-140 Power Amplifier Module Functional Block Diagram.......................... 4-2 Amplifier System Test Setup Diagram........................................................................... 5-3 044-05095 Rev. A ii February 2001 G3S-800-140 Installation & Service Manual List Of Tables Table No. 1-1 1-2 2-1 2-2 3-1 3-2 5-1 5-2 5-3 6-1 Major Amplifier Components .......................................................................................... 1-2 G3S-800-140 MCPA Functional Specifications ............................................................ 1-2 Amplifier Module DC and Logic Connector Definition............................................... 2-3 Amplifier RF Connector Definition ................................................................................. 2-4 Amplifier Module RF Control and Indicators Definition ............................................ 3-2 Amplifier Module Alarm Indicators Definition ............................................................ 3-3 Periodic Maintenance ...................................................................................................... 5-1 Test Equipment Required ................................................................................................. 5-2 MCPA Test Data Sheet...................................................................................................... 5-5 Troubleshooting ................................................................................................................. 6-1 044-05095 Rev. A iii February 2001 G3S-800-140 Installation & Service Manual Section 1 General Description 1-1 Introduction This manual contains information and procedures for installation, operation, and maintenance of Powerwave’s G3S-800-140 multicarrier cellular amplifier. The manual is organized into six sections as follows: Section 1. General Description Section 2. Installation Section 3. Operating Instructions Section 4. Principles of Operation Section 5. Maintenance Section 6. Troubleshooting 1-2 General Description The G3S-800-140 (see figure 1-1) is a linear, feed-forward power amplifier that operates in the 25 MHz frequency band from 869 MHz to 894 MHz. The amplifier can simultaneously transmit multiple frequencies, with better than -60 dBc third order intermodulation distortion (IMD). It is designed for use in an amplifier system that is modular in design, and is ideally suited for use in AMPS/TDMA/CDMA/CDPD/W-CDMA base stations. The plug-in Model G3S-800-140 amplifier modules can each provide 140 watts of power and function completely independently of each other. The amplifier modules are designed for parallel operation to produce high peak power output and backup redundancy for remote applications. All solid-state, the system is designed to provide trouble-free operation with minimum maintenance. The system's modular construction and unique and highly effective LED-based operational status and fault indicators help minimize downtime. The turn-on and turn-off sequences of voltages are fully automatic, as is overload protection and recycling. Inadvertent operator damage from front panel manipulation is virtually impossible. The amplifier module has a status connector that allows the host system to monitor the amplifier module performance. The front panel of each amplifier module has unit level status/fault indicators and an RF on/off/reset switch. Primary power for the amplifier is +27 Vdc. Cooling for each plug-in amplifier module is provided by four fans, two mounted on the front and two on the rear of the module. The fans draw outside air through the front of the module and exhaust hot air out through the rear of the module. 1-3 Functional And Physical Specifications Functional and physical specifications for the amplifier are listed in table 1-2. 1-4 Equipment Changes Powerwave Technologies, Inc. reserves the right to make minor changes to the equipment, including but not necessarily limited to component substitution and circuitry changes. Changes that impact this manual may subsequently be incorporated in a later revision of this manual. 044-05095 Rev. A 1-1 February 2001 G3S-800-140 Installation & Service Manual 1-5 Ordering Information Table 1-1 following gives the part numbers and descriptions to be used when ordering either an entire amplifier or replacement fans. Table 1-1 Major Amplifier Components Model number G3S-800-140 800-01075-003 800-00972-002 Description 140 W 869-894 MHz MCPA Module. Front fan assembly Rear fan assembly. Table 1-2 G3S-800-140 Multicarrier Cellular Amplifier Functional Specifications Frequency Range Total Maximum Input Power Total Output Power Intermodulation Distortion and In-Band Spurious: RF Gain at 880 MHz Gain Flatness: Gain Variation Over Voltage: Output Protection: Input Port Return Loss: Second Harmonics: Out of Band Spurious: Duty Cycle: DC Input Power: Operating Temperature: Storage Temperature: Operating Humidity: Storage Humidity: RF Input / Output Connector Status / Alarm / Control / DC Input Connectors: Dimensions: 044-05095 Rev. A 869-894 MHz (25 MHz Bandwidth) -6.0 dBm 140 W typical (1 Module) -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 Watts 58 dB ± 0.5 dB @ 27 Vdc ±1 Vdc ±0.5 dB from 26 to 28 Vdc Mismatch Protected -16 dB (Min) +5 dBm (Max) Better than -60 dBc, +26 to +28 Vdc Continuous +27 Vdc ± 1 Vdc, 70 Amps Max @ 140 Watts Operational +21.7 to 30 Vdc – 5°C to +50°C -40 ºC. to +85 ºC. 5 % - 95 % Relative Humidity (Noncondensing) 5 % - 95 % Relative Humidity (Noncondensing) BMA Coaxial Female, Radiall 21-Pin D-Subminiature Combo Connector 5.22” High, 17.00” Wide, 20.44” Deep (Including handles, rear fans) 1-2 February 2001 G3S-800-140 Installation & Service Manual Figure 1-1 G3S-800-140 044-05095 Rev. A 1-3 February 2001 G3S-800-140 Installation & Service Manual Section 2 Installation 2-1 Introduction This section contains installation recommendations, unpacking, inspection, and installation instructions for the Multicarrier Cellular Amplifier. Carefully read all material in this section prior to equipment unpacking or installation. Also read and review the operating procedures in Section 3 prior to installing the equipment. It is important that the licensee perform these tasks correctly and in good faith. If applicable, carefully review the Federal Communications Commission (FCC) rules as they apply to your installation. DON'T TAKE CHANCES WITH YOUR LICENSE. 2-2 Electrical Service Recommendations Powerwave Technologies recommends that proper AC line conditioning and surge suppression be provided on the primary AC input to the +27 Vdc power source. All electrical service should be installed in accordance with the National Electrical Code, any applicable state or local codes, and good engineering practice. Special consideration should be given to lightning protection of all systems in view of the vulnerability of most transmitter sites to lightning. Lightning arrestors are recommended in the service entrance. Straight, short ground runs are recommended. The electrical service must be well grounded. Each amplifier system should have its own circuit breaker, so a failure in one does not shut off the whole installation. Circuit breakers should be capable of handling the anticipated inrush current, in a load center with a master switch. 2-3 Unpacking And Inspection This equipment has been operated, tested and calibrated at the factory. Only in the event of severe shocks or other mistreatment should any substantial readjustment be required. Carefully open the container(s) and remove the amplifier module(s). Retain all packing material that can be reassembled in the event that the unit must be returned to the factory. CAUTION Exercise care in handling equipment during inspection to prevent damage caused by rough or careless handling. Visually inspect the amplifier module for damage that may have occurred during shipment. Check for evidence of water damage, bent or warped chassis, loose screws or nuts, or extraneous packing material in the connector or fans. Inspect the rear panel connector for bent connector pins. If the equipment is damaged, a claim should be filed with the carrier once the extent of any damage is assessed. We cannot stress too strongly the importance of IMMEDIATE careful inspection of the equipment and the subsequent IMMEDIATE filing of the necessary claims against the 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 damaged and must be returned to the factory, write or phone for a return authorization. Powerwave may not accept returns without a return authorization. Claims for loss or damage may not be withheld from any payment to Powerwave, nor may any payment due be withheld pending the outcome thereof. WE CANNOT GUARANTEE THE FREIGHT CARRIER'S PERFORMANCE. 044-05095 Rev. A 2-1 February 2001 G3S-800-140 Installation & Service Manual 2-4 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 to the 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). WARNING Verify that all circuit breaker switches on the rear panel of the subrack are in the OFF position. Turn off external primary DC power before connecting DC power cables. 5. Connect positive primary power and negative primary power to the subrack. Tighten the subrack 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 are tight and correct. 8. Measure primary DC input voltage. DC input voltage should be +27 Vdc ±1.0 Vdc. If the DC input voltage is above or below the limits, call and consult Powerwave before you turn on your amplifier system. 9. Refer to section 3 for initial turn-on and checkout procedures. 2-5 Amplifier Module Connectors The amplifier has three connectors on the right rear of the module. The larger is a 21-pin male D-Sub combo which provides the status, alarm, control, and power connections. The smaller BMA coaxial female connectors provide the RF connections. Refer to figure 2-1. Figure 2-1 G3S-800-140 Amplifier, Rear View 044-05095 Rev. A 2-2 February 2001 G3S-800-140 Installation & Service Manual 2-5.1 Amplifier Module Status, Alarm, Control, And Power Connector The amplifier has a separate remote alarm and control connector which may be used by the host system to monitor and control the individual amplifier modules. The status, alarm, control, and power connections on the amplifier connector are made through a 21-pin male D-Sub combo connector (figure 2-2) and are listed and described in table 2-1. A1 2 3 4 5 6 7 8 9 A3 A2 A4 10 11 12 13 14 15 16 17 Figure 2-2 DC and Logic Connector (on Rear of G3S-800-140 Amplifier Module) Table 2-1 Amplifier Module DC and Logic Connector Definition Pin Function A1 A2 A3 A4 Power Input Power Input Ground Ground RS485 +TxD RS485 +RxD Service Loop MCPA Disabled (Summary Fault) 10 11 12 13 14 Mod Addr 0 Mod Addr 1 TP1 Manual Download DC on stat RS485 –TxD RS485 –RxD SCL7 SDA7 FP Disable Output 15 FP RST 16 17 GND Module Detect Description +27 Vdc (Power Contact) +27 Vdc (Power Contact) Ground (Power Contact) Ground (Power Contact) Serial Communication Data Out Serial Communication Data In TTL input to Amp. Gnd. for special test mode (Note 1) TTL signal normally low indicates MCPA enabled. A high level indicates that the MCPA has been disabled. Over Power, Over Voltage takes one second to activate the signal. TTL input to Amp. Gnd. supplied by shelf to identify slot. TTL input to Amp. Gnd. supplied by shelf to identify slot. TTL output. Future test point. GND to download manually TTL output. High indicates Amp is powered on. Serial Communication Data Out Serial Communication Data In No connection No connection Output, GND if the front panel switch is in the OFF position; +5 volts indicates the front panel switch is in the ON position. Output, GND if the front panel switch is in the RESET position; +5 volts otherwise. Ground 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 panel switch when not mounted in the shelf. 044-05095 Rev. A 2-3 February 2001 G3S-800-140 Installation & Service Manual 2-5.2 Amplifier Module RF Connector The amplifier has a separate RF connector which is used for the RF signal input and output. The RF 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. A1 A2 Figure 2-3 Amplifier RF Connector Table 2-2 Amplifier RF Connector Definition Pin A1 A2 044-05095 Rev. A Function RF Input RF Output Description BMA Coaxial Female, Radiall BMA Coaxial Female, Radiall 2-4 February 2001 G3S-800-140 Installation & Service Manual Section 3 Operating Instructions 3-1 Introduction This section contains operating instructions for the Multicarrier Cellular Amplifier System. 3-2 Location And Function Of Amplifier Module Controls And Indicators Primary +27 Vdc power is applied to the amplifier via a 100-amp circuit breaker (ON-OFF) located on the left side of the amplifier front panel. The plug-in amplifier module RF control and indicators, located in the center of the amplifier front panel between the cooling fans, are shown in figure 3-1. The status and RF control functions are described 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 044-05095 Rev. A 3-1 February 2001 G3S-800-140 Installation & Service Manual Table 3-1 Amplifier Module RF Control and Indicators Definition Name Function (Note: MCPA = Multicarrier Power Amplifier) +27VDC Green LED. When lit, indicates that the +27 Vdc supply is greater than +21 Vdc and less than +31 Vdc. If the +27 Vdc indicator goes out, the DC FAIL indicator will illuminate. This indicates that the +27 Vdc voltage dropped below +21 Vdc. Indicator +15VDC Indicator Green LED. When lit, indicates that the +15 Vdc supply is greater than +12 Vdc and less than +17 Vdc. If the +15 Vdc indicator goes out, the DC FAIL indicator will illuminate. This indicates that the +15 Vdc voltage dropped below +12 Vdc or increased above +17 Vdc. +5VDC Indicator Green LED. When lit, indicates that the +5 Vdc supply is greater than +2 Vdc and less than +7 Vdc. If the +5 Vdc indicator goes out, the DC FAIL indicator will illuminate. This indicates that the +5 Vdc voltage dropped below +2 Vdc or increased above +7 Vdc. -5VDC Indicator Green LED. When lit, indicates that the -5 Vdc supply is greater than -7 Vdc and less than -2 Vdc. If the -5 Vdc indicator goes out, the DC FAIL indicator will illuminate. This indicates that the -5 Vdc voltage dropped below -7 Vdc or increased above -2 Vdc. RF ON Switch 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 will turn on one at a time in sequence followed by all the green indicators one at a time in sequence; this will also reset the fault latches. If the switch is held in the reset position, a microcontroller reset will occur. This will be verified by the LEDs toggling state again. The switch is spring loaded to return to the normal ON position when released. If a fault occurs and the MCPA is disabled, the alarms can be cleared and the MCPA enabled by this reset position. The functions of the switch are disabled for five seconds after a power-up condition. 044-05095 Rev. A 3-2 February 2001 G3S-800-140 Installation & Service Manual A ‘Minor Alarm’ will flag a potential fatal problem by the LEDs and the MCPA fault will be in evaluation. A ‘Critical Alarm’ is indicative of a fatal problem. The fault indicator will latch on and the MCPA module will be disabled. A ‘Major Alarm’ indicates a major problem but the MCPA module will not be disabled. Both ‘Major Alarm’ and ‘Critical Alarm’ will be sent to the host system via the MCPA subrack. Table 3-2 Amplifier Module Alarm Indicators Definition Alarm Mode LED MCPA Disable signal Condition Module (pin 4 inTable 2-1) Over Pwr Critical Red Disable High Over Pwr Critical High Temp Minor Red Red Disable Enable High Low High Temp Critical Red Disable High MCPA MCPA module output power >200 watts (Note 4) Input power >-2 dBm High temperature detected High temperature detected for longer than two minutes 14.5 W < Reflected Power < 38W 60W < Reflected power detected at output longer than approx. two min. One of the internal DC voltages dropped below or exceeded the safe threshold level Voltage out of range for longer than approx. two minutes (Note 2) +27 Vdc input >30 V for longer than one sec. after initial detection of DC input >31 V (Note 3) VSWR Minor Red Enable Low VSWR Critical Red Disable High DC Fail Minor Red Enable Low DC Fail Critical Red Disable High Critical Red Disable High Major Red Enable Low Any fan failure Minor Red Enable Low Loop Fail Critical Red Disable High Low Pwr Minor Red Enable Low Low Pwr Critical Red Disable High LPA DISAB. Critical Red Disable High Loop failure detected Loop failure detected longer than 2 minutes Rack controller detected MCPA output is 3 dB below that of the other MCPA in the system. Rack controller detected low power condition for more than approx. two minutes Unit is manually switched off using the front panel RF ON switch, or disabled by a serial command or auto shutdown by an alarm condition. DC Fail (Over voltage) Fan Fail (one) Loop Fail 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 LED c) Set flag for DC Fail alarm 4. When overpower is detected: a) MCPA shall shut down (disable) b) Turn on Over Pwr LED c) Set flag for Over Pwr alarm d) The MCPA module shall use a peak power detector to determine the overpower fault. 044-05095 Rev. A 3-3 February 2001 G3S-800-140 Installation & Service Manual 3-3 Initial Start-Up And Operating Procedures The amplifier module has two operating controls, both located on the front face of the module: the power 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. CAUTION Before applying power, make sure that the input and output of the amplifier are properly 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 damage the amplifier NOTE The output coaxial cable between the amplifier and the antenna must be 50 ohm coaxial cable. 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 to the amplifier system 4. Place the ON - OFF circuit breaker on the amplifier in the ON position. Visually check the indicators 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 module should be on. 5. Set the RF ON switch to the ON (center) position. All red LEDs should turn off after six seconds. 6. Turn on external exciter/transceiver and apply RF input signals. 044-05095 Rev. A 3-4 February 2001 G3S-800-140 Installation & Service Manual Section 4 Principles of Operation 4-1 Introduction This section contains a functional description of the Multicarrier Cellular Amplifier. 4-2 RF Input Signal The maximum input power for all carrier frequencies should not exceed the limits specified in table 1-2. For proper amplifier loop balance, the out of band components of the input signals should not exceed -40 dBc. The input VSWR should be 2:1 maximum (or better). 4-3 RF Output Load The load impedance should be as good as possible (1.5:1 or better) in the working band for good power transfer to the load. If the amplifier is operated into a filter, it will maintain its distortion characteristics 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 distortion at a higher level than the normal forward distortion (i.e. -60 dBc). 4-4 G3S-800-140 Amplifier Module The G3S-800-140 amplifier is a linear, feed-forward power amplifier that operates in the 25 MHz frequency band from 869 MHz to 894 MHz. The amplifier modules are designed for parallel operation 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 peak power) with intermodulation products suppressed to better than -60 dBc below carrier levels. The amplifier provides an amplified output signal with constant gain and phase by adding approximately 30 dB of distortion cancellation on the output signal. Constant gain and phase is maintained by continuously comparing active paths with passive references, and correcting for small variations through the RF feedback controls. All gain and phase variations, for example those due to temperature, are reduced to the passive reference variations. Each amplifier module has an alarm and display board that monitors the amplifier performance. If a failure or fault occurs in an amplifier module, it is displayed on the individual amplifier front panel. The amplifier module is comprised of: Pre-amplifiers Main amplifier Error amplifier Two feed-forward loops with phase-shift and gain controls DC/DC power regulator Alarm monitoring, control and display panel The main amplifier employs class AB amplification for maximum efficiency. The error amplifier and feed forward loops are employed to correct signal nonlinearities 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 shifter in the first feed-forward loop. The main signal is phase shifted by 180 degrees and amplified in the premain amplifier. The output from the premain amplifier is fed to the class AB main amplifier. The output from the main amplifier 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 is combined with the main input signal and input to the second feed-forward loop. The error signal is 044-05095 Rev. A 4-1 February 2001 G3S-800-140 Installation & Service Manual attenuated, phase shifted 180 degrees, then fed to the error amplifier where it is amplified to a level identical to the sampled output from the main amplifier. The output from the error amplifier is then coupled back and added to the output from the main amplifier. The control loops continuously make adjustments to cancel out any distortion in the final output signals. 1st Loop Phase & Gain Pre Main FWD PWR Pre Amp RF Out Main Amp 2nd Loop Phase & Gain Delay Delay -30dB -10dB RFL PWR Error Amp Feed Forward Loop control +15 +5 -5 +27VDC Power Supply Alarms & Display Front Panel Smart Rack Figure 4-1 G3S-800-140 Power Amplifier Module Functional Block Diagram The 2nd loop control section obtains a sample of the distortion added to the output signals by the main 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 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 canceled out. 4-4.1 Main Amplifier The input and output of the amplifier employ two-stage, class AB amplifiers which provide approximately 32 dB of gain in the 25 MHz frequency band from 869 to 894 MHz. The amplifier operates on +27 Vdc, and a bias voltage of +5 Vdc, and is mounted directly on a heat sink which is temperature monitored by a thermostat. If the heat sink temperature exceeds 85 °C, the thermostat opens and a high temperature fault occurs. The alarm logic controls the +5 Vdc bias voltage which shuts down the amplifier. 4-4.2 Error Amplifier The main function of the error amplifier is to sample and amplify the signal distortion level generated by the main amplifier, to a level that cancels out the distortion and IMD when the error signal is coupled onto the main signal at the amplifier output. The error amplifier is a balanced multistage, class AB amplifier, has 51 dB of gain, and produces up to an 80-watt output. The amplifier operates on 27 Vdc and a bias voltage of +5 Vdc, and is mounted directly on a heat sink. 4-4.3 Amplifier Monitoring In the main and error amplifier modules, all normal variations are automatically compensated for by the feedforward loop control. However, when large variations occur beyond the adjustment range of the loop control, a loop fault will occur. The alarms are displayed on the front panel indicators and output via a 21-pin connector on the rear of the module to the subrack summary board for subsequent remote monitoring via the ALARMS connector. Refer to paragraph 2-5 as well as figure 2-2 and table 2-2 for a description of the ALARMS connector. 044-05095 Rev. A 4-2 February 2001 G3S-800-140 Installation & Service Manual 4-4.4 Amplifier Module Cooling Although each amplifier module contains its own heat sink, it is cooled with forced air. Four fans are used for forced air cooling and redundancy. The fans, located on the front and rear of the amplifier module, draw air in through the front of the amplifier and exhaust hot air out the back of the module. The fans are field replaceable. 4-5 Power Distribution Primary DC power for the system is provided by the host system to the MCR30830-1-3 Series subrack. The subrack supplies each amplifier module with +27 Vdc directly and via the RF power splitter/combiner. The amplifier module has a DC/DC converter that converts the +27 Vdc to +15 Vdc, +5 Vdc and -5 Vdc. 4-6 Intermodulation The G3S-800-140 amplifier is designed to deliver a 140-watt composite average power, multicarrier signal, occupying a bandwidth less than or equal to 25 MHz, in the bandwidth from 869 to 894 MHz. The maximum average power for linear operation, and thus the amplifier efficiency, will depend on the type of signal amplified. 4-6.1 Two Tone Intermodulation When measured with two equal CW tones spaced anywhere from 30 kHz to 20 MHz apart, and at any power level up to the average power, the third order intermodulation products will be below -60 dBc 4-6.2 Multitone Intermodulation Adding more tones to the signal will lower individual intermodulation products. If the frequencies are not equally spaced, the level of intermodulation products gets very low. When the frequencies are equally spaced, those products fall on top of each other on the same frequency grid. The average power of all intermodulation beats falling on the same frequency is called the composite intermodulation; it is -60 dBc or better. 4-7 Alarms The presence of several plug-in amplifier alarms can be detected at the DC and logic connector on the amplifier rear panel. Refer to table 2-1 and figure 2-2 for a description of the connector. 044-05095 Rev. A 4-3 February 2001 G3S-800-140 Installation & Service Manual Section 5 Maintenance 5-1 Introduction This section contains periodic maintenance and performance test procedures for the Multicarrier Cellular Amplifier. It also contains a list of test equipment required to perform the identified tasks. NOTE Check your sales order and equipment warranty before attempting to service or repair the unit. Do not break the seals on equipment under warranty or the warranty will be null and void. Do not return equipment for warranty or repair service until proper shipping instructions are received from the factory. 5-2 Periodic Maintenance Periodic maintenance requirements are listed in table 5-1. Table 5-1 also lists the intervals at which the tasks should be performed. WARNING Wear proper eye protection to avoid eye injury when using compressed air. Table 5-1 Periodic Maintenance Task Cleaning Air Vents Inspection Cables and Connectors Performance Tests Interval Action 30 Days Inspect and clean per paragraph 5-4 12 Months Inspect signal and power cables for frayed insulation. Check RF connectors to be sure that they are tight. Perform annual test per paragraph 5-5. 12 Months 5-3 Test Equipment Required For Test Test equipment required to test the amplifier system is listed in table 5-2. Equivalent test equipment may be substituted for any item, keeping in mind that a thermistor type power meter is required. NOTE All RF test equipment must be calibrated to 0.05 dB resolution. Any deviation from the nominal attenuation must be accounted for and factored into all output readings. 044-05095 Rev. A 5-1 February 2001 G3S-800-140 Installation & Service Manual Table 5-2 Test Equipment Required Nomenclature Signal Generator 30 dB Attenuator, 500 Watt 20 dB Attenuator, 20 Watt (2 each) Spectrum Analyzer Coax Directional Coupler Power Meter/Sensor Network Analyzer Current Probe Manufacturer RDL Weinschel Corp. Tenuline Model IMD-801D-03A 53-30-34 H.P. H.P. H.P. H.P. 8560E 778D 437B/8481A 8753C 5-4 Cleaning Air Inlets/Outlets The air inlets and outlets should be cleaned every 30 days. If the equipment is operated in a severe dust environment, they should be cleaned more often as necessary. Turn off DC power source before removing fans. If dust and dirt are allowed to accumulate, the cooling efficiency may be diminished. Using either compressed air or a brush with soft bristles, loosen and remove accumulated dust and dirt from the air inlet panels. 5-5 Performance Test Performance testing should be conducted every 12 months to ensure that the amplifier system meets the operational specifications listed in table 5-3. Also verify system performance after any amplifier module is replaced in the field. The test equipment required to perform the testing is listed in table 5-2, and the test setup is shown in figure 5-1. NOTE The frequencies used in this test are typical for an amplifier with a 25 MHz band from 869 MHz to 894 MHz. Select evenly spaced F1, F2, F3, and F4 frequencies that cover the instantaneous bandwidth of your system. 5-5.1 Amplifier System Performance Test This test is applicable to the G3S-800-140 amplifier modules. To perform the test, proceed as follows: 1. Connect test equipment to the amplifier as shown in figure 5-1. NOTE Do 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 from all four signal generators equals -6 dBm at the input. 044-05095 Rev. A 5-2 February 2001 G3S-800-140 Installation & Service Manual Unit Under Test +27 Vdc Gnd G3S-800-140 Plug-in Amplifier Module RF Out 30 dB Attenuator 20 dB Directionl Coupler 20 dB Attenuator 500 W 20 W Power Meter RF In 20 W 20 dB Attenuator Directionl Coupler Spectrum Analyzer 8651E Sensor Head 8482A Network Analyzer 8753C Filter / Isotlator Signal Generator 10 dB Variable Attenuator Sensor Head 8482A Power Meter Figure 5-1 Amplifier System Test Setup Diagram 5-5.2 Amplifier IMD Test And Current Test 2. Adjust attenuator for an input signal at -10 dBm. Turn on the amplifier by setting RF ON switch of amplifier. Adjust variable attenuator to set amplifier power output on power meter to 140 watts. Measure IMD on spectrum analyzer. IMD should be -60 dBc max. Record test data 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 (magnetic field type) and measure the dc current flow from the +27 Vdc power source. Current should be 70 amps maximum. Record test data in table 5-3. 5-5.3 Gain Test 4. 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 Test 7. 10.With the power set at 140 watts power output, use the spectrum analyzer and check the frequency band from 869 MHz to 894 MHz for harmonics. Harmonics should be 5 dBm maximum. Record test data in table 5-3. 044-05095 Rev. A 5-3 February 2001 G3S-800-140 Installation & Service Manual 5-5.5 Spurious Test 8. 5-5.6 9. With the power amplifier set at 140 watts power output, use the spectrum analyzer and check the frequency band from 869 MHz to 894 MHz for spurious signals. Spurious signals should be -60 dBc maximum. Record test data in table 5-3. Input Return Loss Test Reset and turn on amplifier module. Read and record the S11 return loss measurement on network analyzer. Input return loss should be –16 dB maximum. Record test data in table 5-3. 044-05095 Rev. A 5-4 February 2001 G3S-800-140 Installation & Service Manual Table 5-3 Multicarrier Cellular Amplifier Test Data Sheet DATE _________________________________ AMPLIFIER S/N _________________________ TEST CONDITIONS: Load and Source Impedance: 50 Ohms VSWR: < 1.2:1 Supply Voltage: +27 Vdc ±1.0 Vdc TEST 4-TONE IMD RF Gain Gain Flatness Harmonics Spurious Input Return Loss DC Power SPECIFICATION Vcc = 27 Vdc PO = 140 W Freq.: 880, 883, 886, and 889 MHz Vcc = 27 Vdc PO = 140 W Freq. = 880 MHz Vcc = 27 Vdc ±1 Vdc PO =140 W 869-894 MHz Band Vcc = 27 Vdc PO = 140 W 869-894 MHz Band Vcc = 27 Vdc PO =140 W 869-894 MHz Band Vcc = 27 Vdc PO = 140 W 869-894 MHz Band Vcc = 27 Vdc PO = 140 W 4 Tones MIN MAX DAT -60 dBc 57.5 dB 58.5 dB -0.5 dB +0.5 dB 5 dBm -60 dBc -16 dB 70 Amps PASS _________________________________ FAIL _______________________________ Tested by ______________________________ 044-05095 Rev. A 5-5 February 2001 G3S-800-140 Installation & Service Manual 5-6 Field Replaceable Parts And Modules The following parts and modules can be replaced in the field on site by a qualified technician with experience maintaining RF power amplifiers and similar equipment: 1. G3S-800-140 power amplifier modules 2. Cooling fans 5-6.1 G3S-800-140 Power Amplifier Module To 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 of the 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. CAUTION When removing the amplifier from the subrack, it is very important to support the amplifier such that the rear of the module does not suddenly drop when it disengages from the track. A drop such as this could damage the module. 5-6.2 Cooling Fans To 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 connector from amplifier module. Install replacement in reverse order of steps 1 and 2 above. 044-05095 Rev. A 5-6 February 2001 G3S-800-140 Installation & Service Manual Section 6 Troubleshooting 6-1 Introduction This section contains a list of problems which users have encountered and a few suggested actions that may correct the problem. If the suggested corrective action does not eliminate the problem, please contact your Powerwave field representative or the factory for further instructions. NOTE Check your sales order and equipment warranty before attempting to service or repair the unit. Do not break the seals on equipment under warranty or the warranty will be null and void. Do not return equipment for warranty or repair service until proper shipping instructions are received from the factory. 6-2 Troubleshooting Refer to table 6-1 for troubleshooting suggestions. Table 6-1 Troubleshooting. Symptom Any voltage indicators (green) are not lit or blinking HIGH TEMP alarm (red) is lit OVER PWR alarm (red) is lit VSWR alarm (red) is lit LOW PWR alarm (red) is lit Suggested Action 1. 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. 1. Verify fan(s) are operating properly. 2. Check ambient temperature (not to exceed spec – see table 1-2). Verify RF input level does not exceed spec – see table 1-2. Check output connections and cables for integrity and tightness. Contact Powerwave field representative or factory. 6-3 Return for Service Procedures When returning products to Powerwave, the following procedures will ensure optimum response. 6-3.1 Obtaining an RMA A Return Material Authorization (RMA) number must be obtained prior to returning equipment to the factory for service. Please contact our Repair Department at (714) 466-1000 to obtain this number, or FAX your request to (714) 466-5800. Failure to obtain this RMA number may result in delays in receiving repair service. 6-3.2 Repackaging for Shipment To ensure safe shipment of the amplifier, it is recommended that the package designed for the amplifier be used. The original packaging material is reusable. If it is not available, contact our Repair Department for packing materials and information. 044-05095 Rev. A 6-1 February 2001
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