Communication Components BDA-1819-60 BI-DIRECTIONAL AMPLIFIER User Manual New manual

Communication Components Inc BI-DIRECTIONAL AMPLIFIER New manual

New manual

INSTALLATION MANUAL for BI-DIRECTIONAL AMPLIFIERS Communication Components Inc.299 Forest Ave, Paramus, N.J. 07652 Tel: 201-265-8882, Fax: 201-265-8922
TABLE OF CONTENTS1. Theory of Operation2. Intended Application 3. Technical Description 4. Installation Procedure 5. Antenna installation safety precautions
1. THEORY OF OPERATIONThe BDA-1819-60 is a bi-directional amplifier. It. is designed to exchange radiocommunications in buildings, basements, tunnels and other RF shielded environments.The BDA improves the sensitivity of base stations in indoor locations where there is asignificant amount of cable loss in RF distribution systems.It contains two amplifiers providing amplification of RF signals in Up-link and Down-linkfrequency bands. They are connected to the external cables via frequency selectiveduplexers in order to attenuate all signals that are not in the designated bands. 2. INTENDED APPLICATIONBDA is intended for commercial non-consumer applications and has to be installed byPCS service providers or their qualified subcontractors at the locations where the signalstrength from the base station is insufficient to provide quality communication service. Unit is not intended for in-home use to boost output of typical consumer type transmitters(phones, wireless local loops, etc).
3. TECHNICAL DESCRIPTIONThe BDA-1819-60 bi-directional amplifier provides signal amplification in two separatefrequency bands in both directions between two coaxial connector terminals. It is achievedby utilization of two frequency selective duplexers, which direct signals at two frequencybands present at the common port in two outputs. These duplexers provide sufficientlyhigh isolation between two paths to prevent self-oscillation of the system. Detailed block-diagram is shown in Figure 1.The amplifier consists from several gain stages with the low noise stage at the input andmedium power stage at the output. All amplifier stages operate at class A linear regime inorder to provide the lowest possible intermodulation products.The duplexer serves two purposes: it splits the signal from the common port to twodifferent ports, and it provides frequency selectivity and isolation between two paths. Thecommon port of the first duplexer is called “BASE STATION”. The common port of theother duplexer is called “SERVICE AREA”.Only signals within the frequency range of 851-866 MHz band will be amplified comingfrom the BASE STATION port and only signals within the frequency range of 806-821MHz band will be amplified from the SERVICE AREA port.In this configuration the BDA amplifies signals in the Up-link band in one direction andsignals in the Down-link band in the other direction.Physically the BDA block consists of a single compact unit with two RF connectors. It isrugged and can be easily connected during cable installation. It has a moisture proofNEMA 4X enclosure suitable for indoor and outdoor installation with two low noisemedium power amplifiers, optional independently controlled Up-link and Down-linkattenuators, two duplexers, and optional bias tee’s.The BDA can be powered by a conventional 110/220 VAC source using a built-in powersupply or alternatively DC voltage can be supplied to the BDA via an external DC inputor via center conductor of the RF coax cable.
Figure 1Line Bi -Directional AmplifierBLOCK DIAGRAMRx/Tx DUPLEXER RxBPF TxBPFRx/Tx DUPLEXERBIAS TEE Rx BPFTxBPFBIAS TEEAMPAMPVariableAttenuatorAMPAMPVariableAttenuatorVariable attenuators and AGC are optionalACPowerSupplyBias Tee’s are optional
4. INSTALLATION PROCEDURE4.1 NSPECTION Open the enclosure of the bi-directional amplifier (BDA) and carefully inspect the insideassembly of the unit.Verify that all components are properly secured to the base of enclosure, there are no loseparts, and all interconnections are reliable. 4.2 SITE INSTALLATION4.2.1 The bi-directional amplifier can be installed as a freestanding unit lying on the shelfof the cabinet or any other adequately strong support. It can also be secured by screws tothe wall or rack using four holes in the tabs located at the back plate of the enclosure. It isrecommended that the environmental temperature will not exceed 65 C and the area willbe adequately ventilated.4.2.2 Once amplifier is installed in place, open the front door and verify that all internalparts are securely mounted. 4.2.3 Connect the ground wire to ground stud on the enclosure.4.2.4 Plug in the AC cable into the AC socket to turn on the amplifier. The green light onthe enclosure must be lit on.4.2.5 Connect spectrum analyzer to the input (donor antenna) cable. Measure the signallevel in the cable coming into the Down-link port of the amplifier. If the signal level isabove –40 dBm, add attenuator with the corresponding value or use internal attenuator, ifthe BDA option is so equipped.4.2.6 Repeat the same for the cable that will be connected to the Up-link port of theamplifier.4.2.7 Connect the spectrum analyzer via 20 dB pad to the Down-link port of the BDA. CAUTIONUse caution working with the bi-directional amplifier.Disconnect the 115 VAC from the amplifier prior toinspection.
Connect the “donor” side cable to the Up-link port of the BDA. Observe the level of theamplified signals on the spectrum analyzer. Adjust the gain (if the BDA option is soequipped) or external (internal, if so equipped) attenuator value to limit the power of thesignals to +23 dBm for CDMA, +26 dBm for GSM, or +25 dBm for TDMAapplications.4.2.8 Repeat the same measurements connecting the spectrum analyzer to the Up-linkport and cable to the Down-link port. Adjust the level of amplified signals at the Up-linkport to +23 dBm for CDMA, +26 dBm for GSM, or +25 dBm for TDMA applications.4.2.9 Record the settings of attenuators.4.2.10 Connect the Up-link cable to the amplifier. Check the security of the installationand presence of the AC power. Amplifier is ready for operation. 4.3 REMOVE BI-DIRECTIONAL AMPLIFIER4.3.1 Unplug the AC cord from the socket. AC light on the amplifier must be off.Disconnect all coaxial cables.4.3.2 Dismount amplifier from the wall or remove it from the shelf. 4.4 SHIPMENT AND STORAGE OF THE BDA4.4.1 Use common technical shop practices to ensure equipment protection duringshipment or storage. 4.5 TROUBLESHOOTING AND FAULT DETECTION4.5.1 Check the presence of the AC power. The AC light must be on.4.5.2 Check the continuity of all connecting cables.4.5.3 If the fault was not located, remove the amplifier and send it to the manufacturer forrepair.4.5.4 RF testing of the amplifier is possible in the specially equipped laboratory. WARNING!110 VAC CAN BE LETHAL!ALWAYS UNPLUG THE AMPLIFIERBEFORE SERVICING THE INTERIOR..
4.6.0 INFORMATION TO USERAny changes or modifications to this product as well as usage outside of specifiedelectrical parameters, which are not expressly approved by manufacturer, could voidthe user’s authority to operate the equipment.5. Antenna Installation Safety Recommendations
Typical installation is shown in Fig.2 Two antennas are used in this set-up. One antennawith higher gain (10 dbi typically) and narrow beam, which is called Donor Antenna, ispointed to the Base Station. It provides down-link signals for the BDA input and directsup-link signals from the output of BDA to the Base Station.The second antenna, which is called Service Antenna, usually located on the ceiling of theservice area. Low gain omni-directional antenna is normally used with typical gain 5 dBito 2 dBi.Because antennas are open space radiating structures, the following precautions arerecommended:Do not make any RF interconnections while BDA is operatingDo not approach Donor Antenna closer than 1 ft when the BDAis operating. Mark the installation site accordingly.Service Antenna must be installed sufficiently high in such away that the distance between the antenna and the mobilephone user will always be more than 1 foot.Do not use antennas with gain above 10 dBi in the service area. Fig. 2BS HH RadioDonorAntenna ClosetBDAServiceAntenna

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