Westell CSI110-01 Bidirectional Amplifier User Manual 1

Westell, Inc. Bidirectional Amplifier 1

Contents

User Manual 1

1Mini-IBA Manual-A05/17/01Cellular Specialties, Inc.Model 110 Miniature In-Building AmplifierOperation and Users Manual
2Mini-IBA Manual-A05/17/01Table of Contents1. Product DescriptionBackgroundFunctional DescriptionCircuit DescriptionFunctional Block DiagramOutline Drawing2. General Specifications3. Inspection and InstallationInspection of ContentsPackage ContentsInstallationSafety
3Mini-IBA Manual-A05/17/011. Product DescriptionBackgroundThe performance of a cell phone can be easily degraded when in enclosedstructures where signals from a local cell site are not sufficient for reliablephone operation. The Model 110 Miniature In-Building Amplifier (Mini-IBA) was developed by Cellular Specialties, Inc. (CSI) to enhance cellularperformance within these enclosed structures. Specifically, the Mini-IBA isdesigned to cover small areas such as home offices, small workshops, etc.Functional DescriptionThe Mini-IBA boosts the cellular performance by providing amplification ofboth transmit and receive signals. The unit receives the portable phone’ssignal through an interior antenna, amplifies it and then sends it to an outsideantenna. This signal is referred to as the “Uplink”. The Mini-IBA alsoreceives signals from the Cell Site base station through the outside antenna.This signal is amplified and re-radiated to the portable phone and is referredto as the “Downlink”. It is necessary that sufficient signal be available at theexternal antenna.The external antenna is usually a directional type such as a “Yagi”, howeveran Omni-directional antenna may be used when the structure is located inclose proximity to one or more cell sites. Internal antennas are usuallyOmni-directional although other types, such as low profile wall or ceilingmount, may be used for special installations.As shown in Figure 1, there are three stages of gain in the Downlink and 2stages in the Uplink for a nominal gain of 40 dB in each link. The maximumlinear output power for the Uplink is 500 milli-Watts and 30 milli-Watts forthe Downlink.An LED indicator on the unit shows the application of power.
4Mini-IBA Manual-A05/17/01Circuit DescriptionUplinkThe uplink rf circuit consists of two stages of gain. Each gain stage is amonolithic integrated circuit (mmic) mounted to a printed circuit board(PCB). The signal received by the inside antenna is directed to the 1st mmicstage by a frequency diplexer, which separates the uplink frequency (806-824 MHz) from the downlink frequency (851-869MHz). This signal isamplified by both mmic stages and directed to an identical diplexer at theoutput of the 2nd stage. Both stages are biased for linear operation. Theoverall gain from the inside antenna terminal to the outside antenna terminalis nominally 40 dB. Each diplexer provides 60 dB of rejection between theuplink amplifier chain and the downlink.DownlinkThe downlink circuit is similar in operation to the uplink, in that it also usestwo stages of mmic amplification. The major differences are the downlinkfrequency (851-869 MHz), the overall gain (30 dB) and signal flow in theopposite direction.Power SupplyAll the mmic amplification stages, in both the uplink and downlink, operatefrom a single supply voltage of +5 Vdc. A linear regulator is used toprovide the 5 volts from an input of 12 Vdc. All internal dc circuits arefiltered and de-coupled from the rf circuits. A 115 Vac to 12 Vdc “Wall”supply is provided as part of the unit. The overall current at 12 Vdc is lessthan 1.0 Amp.
5Mini-IBA Manual-A05/17/01FIGURE 1 Functional Block DiagramFIGURE 2 Outline Drawing
6Mini-IBA Manual-A05/17/012. General SpecificationsAll specifications stated as typical unless otherwise noted. Cellular Specialties, Inc.reserves the right to change these specifications at any time without prior notice.Downlink UplinkFrequency Band 850-870 MHz 806-824 MHzGain 40 dB 40 dBTypical Power Out +28 dBm +15 dBmNoise Figure 6 dB 6 dB3rd Order Intercept +43 dBm +27 dBmPropagation Delay <1 microsecond <1 microsecondVSWR <2:1 <2:1Passband Ripple (max) 2 dB pk-pk 2 dB pk-pkConnectors Mini-UHFPower Requirements +6 Vdc, 1.0 ADimensions 3.5”x4.0”x1.2”Weight 1 lbs.Indicator LED “Power-On”
7Mini-IBA Manual-A05/17/013. Inspection and InstallationInspectionInspect the equipment as soon as possible after purchase. If any part of theequipment has been damaged in transit, report the damage to thetransportation company and also to the company where purchased.ContentsThe unit package contains the following:Model 110 Mini-IBAPower Transformer, 110 volt to 6 volt – model number ( )User ManualOptional AccessoriesAccessories are available directly from Cellular Specialties, Inc. or any ofCSI’s distributors.Exterior High Gain Antenna – model number ( )Exterior Omni Antenna – model number ( )Interior Omni Antenna – model number ( )Power Cable w/cigarette lighter adapter – model number ( )InstallationThe installation of the Mini-IBA is relatively simple. If possible,measurements of the Received Signal Strength Indicator (RSSI) should berecorded as close as possible to the proposed exterior antenna location.Optimum performance will be obtained with RSSI readings greater than –85dBm.With the exact location of the exterior antenna and the coordinates of the cellsits closest to the building in which the unit is being installed, the distanceand bearings to each of the local cells can be determined. The first choicewould be the closest site unless there is blockage in the form of buildings orterrain. If blockage exists, an alternate site may be available.If coordinates are not available, measure the RSSI at the external antennaoutput by connecting a phone to the external antenna and slowly rotating theantenna until a maximum reading is obtained.
8Mini-IBA Manual-A05/17/01The Mini-IBA and interior antenna should be centrally located, keepingcoaxial cable runs to a minimum. A maximum length of 100 feet of low losscable is recommended. The actual coax used should be RG-8 type with aflame retardant rating as a minimum. If the coax is run through an areawhere heating and/or cooling air is channeled, a plenum rated coax shouldbe used. When mounting the amplifier, take care to avoid areas of high heator extreme cold. In general, do not place the unit on or near the top of highceilings, by heaters or in cold storage areas.During installation, care must be taken to provide the maximum isolationbetween interior and exterior antennas. This isolation should be in the orderof 70 dB to prevent any re-generative feedback in the system. Feedback ofthis nature may cause the amplifier to emit a continuous signal at maximumamplitude and could, in some cases, interfere with the normal operation ofthe cell site.There are no installation or user adjustments or tuning on this unit.CAUTIONInside antennas should be positioned to observe minimumseparation of 2.3 cm. (~ 1.0 in.) from any workstation.Personnel working in the vicinity of inside (downlink)antennas should observe the following guidelines forminimum distances between the human body and theantenna when establishing the position of new workstations.The placement of a workstation must be in excess of 2.3 cm. (~ 1.0 in.) fromany interior antenna. Exceeding this minimum separation will ensure thatthe employee does not receive RF-exposure beyond that MaximumPermissible Exposure according to section 1.1310 i.e. limits for GeneralPopulation/Uncontrolled Exposure.!!!!

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