Westell BA14X Amplifier User Manual Cellular Specialties Inc

Westell, Inc. Amplifier Cellular Specialties Inc

Users Manual

Cellular Specialties, Inc. Model 140 Miniature In-Building Amplifier Operation and Users Manual 1 140 BDA Rev. 1 5/29/03
Table of Contents 1. Product Description Background Functional Description 2. General Specifications 3. Inspection and Installation Inspection of Contents Package Contents Installation Safety 2 140 BDA Rev. 1 5/29/03
1. Product Description Background The performance of a cell phone can be easily degraded when in enclosed structures where signals from a local cell site are not sufficient for reliable phone operation. The Model 140 Miniature In-Building Amplifier (Mini-IBA) was developed by Cellular Specialties, Inc. (CSI) to enhance cellular performance within these enclosed structures. Specifically, the Mini-IBA is designed to cover small areas such as home offices, small workshops, etc. Functional Description The Model 140 amplifier boosts the wireless network’s performance by providing amplification of both transmit and receive signals. The unit receives the portable phone’s signal through an inside antenna, amplifies it and then sends it to an outside antenna. This signal is referred to as the “Uplink”. The amplifier also receives signals from the Cell Site base station through the outside antenna. This signal is amplified and re-radiated to the portable phone and is referred to as the “Downlink”. It is necessary that sufficient signal be available at the outside antenna. The outside antenna is usually a directional type such as a “Yagi”, however an Omni-directional antenna may be used when the structure is located in close proximity to one or more cell sites. Inside antennas are usually Omni-directional although other types, such as low profile wall or ceiling mount, may be used for special installations. As shown in Figure 1, there are four stages of gain in the Downlink and four stages in the Uplink providing nominal gain of 40 dB in each link. The maximum linear output power is 160 milliwatts for the Uplink and 160 milliwatts for the Downlink. These levels are factory set and are maintained by an internal Automatic Gain Control (AGC) circuit. Four LED indicators on the unit indicate: • Green “Power” LED indicates that power is applied and the unit is operating. • Yellow “AGC” LED indicates that the gain of the Uplink and/or Downlink is being reduced to maintain the maximum power 3 140 BDA Rev. 1 5/29/03
output, which prevents spurious radio-frequency emissions from the amplifier. • Yellow “Isolation” LED indicates that the microcontroller in the unit has sensed instability due to insufficient isolation between the inside antenna and the outside antenna, and has reduced the gain of the amplifier. This is done to prevent oscillation, which can interfere with the handsets in the covered area and/or the wireless service provider’s base station. This “degraded mode” will be maintained until the amplifier power is disconnected and reconnected. The outside antenna should be placed as far as practical from the internal antenna, and should not be pointed toward the inside antenna. • Red “Shutdown” LED indicates that the gain of the unit has been reduced to minimum to prevent very strong input signals from overloading the amplifier. The amplifier will attempt to recover from this condition, initially at fifteen intervals and then at four-minute intervals. 4 140 BDA Rev. 1 5/29/03
2. General Specifications All specifications stated as typical unless otherwise noted. Cellular Specialties, Inc. reserves the right to change these specifications at any time without prior notice. Downlink Uplink Frequency Band 851-869 MHz (SMR) 869-894 MHz (Cellular) 806-824 MHz (SMR) 824-849 MHz (Cellular) Linear Gain (dB) 40 40 Typical Power Out (max) Linear * ** +22 dBm +22 dBm Noise Figure 6 dB 6 dB Propagation Delay <150 nsec. <150 nsec. Passband Ripple (max) 4 dB pk-pk 4 dB pk-pk Connectors Type N female Power Requirements +5 Vdc, 1.5 A Temperature -40º F to +122º C; -40º C to +50º C Dimensions 6.1 x 3 x 1 inch; 15.4 x 7.6 x 2.5 cm. Weight (amplifier only) 1.2 lb.; 0.55 kg. Indicator LEDs Power, AGC, Isolation, Shutdown Regulatory Approvals FCCID: NVRBA14X IC: 4307A-BA14X8 NOTES * The manufacturer’s rated output power of this equipment is for single carrier operation. For situations when multiple carrier signals are present, the rating must be reduced by 3.5 dB, especially where the output signal is re-radiated and can cause interference to adjacent band users. This power reduction is to be by means of input power or gain reduction and not by an attenuator at the output of the device. ** Maximum total output power without exceeding the FCC allowable emissions of –13 dBm. 5 140 BDA Rev. 1 5/29/03
3. Inspection and Installation Inspection Inspect the equipment as soon as possible after purchase. If any part of the equipment has been damaged in transit, report the damage to the transportation company and also to the company where purchased. Contents The unit package contains the following: Model 140 Amplifier Power Transformer, 110 volt to 5 volt User Manual Installation Note: The Installer should refer to the Safety Precautions, in the following section, for proper antenna selection and installation The installation of the Mini-IBA is relatively simple. If possible, measurements of the Received Signal Strength Indicator (RSSI) should be recorded as close as possible to the proposed outside antenna location. Optimum performance will be obtained with RSSI readings greater than –85 dBm. With the exact location of the outside antenna and the coordinates of the cell sites closest to the building in which the unit is being installed, the distance and bearings to each of the local cells can be determined. The first choice would be the closest site unless there is blockage in the form of buildings or terrain. If blockage exists, an alternate site may be available. If coordinates are not available, measure the signal strength at the outside antenna output by connecting a phone to the outside antenna and slowly rotating the antenna until a maximum reading is obtained. NEVER CONNECT A PHONE DIRECTLY TO THE AMPLIFIER. The amplifier and inside antenna should be centrally located, keeping coaxial cable runs to a minimum. A maximum length of 100 feet of low loss 6 140 BDA Rev. 1 5/29/03
cable is recommended. The actual coax used should be RG-8 type or better with a flame retardant rating as a minimum. If the coax is run through an area where heating and/or cooling air is channeled, a plenum rated coax must be used. When mounting the amplifier, take care to avoid areas of high heat or extreme cold. In general, do not place the unit on or near the top of high ceilings, by heaters or in cold storage areas. During installation, care must be taken to provide the adequate isolation between inside and outside antennas. It is good practice to install the antennas where that there are metal and/or concrete building obstructions between the antennas, such as concrete floors, elevator shafts, restroom areas, chimneys, etc. The outside antenna should never be pointed in the direction of any inside antenna unless significant metal/concrete obstructions or significant height difference exists between the antennas. Isolation should be at least 55 dB to prevent re-generative feedback in the system. Feedback of this nature could cause the amplifier to emit a continuous signal at maximum amplitude. The Model 140 amplifier’s controller will detect inadequate isolation and will reduce the gain of the amplifier to prevent oscillation (yellow “Isolation” indicator indicates this condition). Though the amplifier will continue to operate, its performance is reduced and the inadequate isolation condition should be corrected. If the yellow “Isolation” LED is on, re-orient the outside and / or inside antennas to minimize signals between the antennas and reset the amplifier by disconnecting and reconnecting the power supply at the amplifier. The gain of the amplifier will remain in a reduced state until adequate isolation is achieved and it is reset. There are no installation or user adjustments or tuning on this unit. 7 140 BDA Rev. 1 5/29/03
Safety Precautions CAUTION !For INDOOR use, an Omni-Directional Antenna with a maximum gain of 8 dBi is authorized for use with this unit. Inside antennas must be positioned to observe minimum separation of 20 cm. (~ 8 in.) from all users and bystanders. For the protection of personnel working in the vicinity of inside (downlink) antennas, the following guidelines for minimum distances between the human body and the antenna must be observed. The installation of an INDOOR antenna must be such that, under normal conditions, all personnel cannot come within 20 cm. (~ 8.0 in.) from any inside antenna. Exceeding this minimum separation will ensure that the employee or bystander does not receive RF-exposure beyond the Maximum Permissible Exposure according to section 1.1310 i.e. limits for General Population/Uncontrolled Exposure. !For OUTDOOR use, a Directional Antenna up to a maximum gain of 10 dBi is authorized for use with this unit. The Outside antenna must be positioned to observe minimum separation of 120 cm. (~ 4 ft.) from all users and bystanders. For the protection of personnel working in the vicinity of outside (uplink) antennas, the following guidelines for minimum distances between the human body and the antenna must be observed. The installation of an OUTDOOR antenna must be such that, under normal conditions, all personnel cannot come within 120 cm. (~ 4 ft.) from the outside antenna. In all installations, the antenna should never be mounted such that the main beam is directed toward an area where workers or bystanders may be present. Exceeding this minimum separation will ensure that the worker or bystander does not receive RF-exposure beyond the Maximum Permissible Exposure according to section 1.1310 i.e. limits for General Population/Uncontrolled Exposure. 8 140 BDA Rev. 1 5/29/03

Navigation menu