INSTALLATION OPERATING MANUAL BDA-PCS/X-1/1W-XX-B BI-DIRECTIONAL AMPLIFIER AND FOR TABLE OF CONTENTS PAGE NO 3 3 4 5 6 7 7 7 8 9 10 11 12 13 PARAGRAPH BDA OVERVIEW BDA BLOCK DIAGRAM DESCRIPTION BDA BLOCK DIAGRAM DRAWING (Figure 1) ELECTRICAL SPECIFICATIONS FREQUENCY RANGES (Table 1) MECHANICAL SPECIFICATIONS ENVIRONMENTAL CONDITIONS BDA CONNECTIONS MECHANICAL OUTLINE DRAWING (Figure 2) RF EXPOSURE WARNING BDA INSTALLATION BDA OPERATION MECHANICAL OUTLINE- ADJUSTMENT (Figure 3) DIAGNOSTICS GUIDE Page 2 BDA OVERVIEW:
The BDA assembly extends the coverage area of radio communications in buildings and RF shielded environments. The unit features low noise figure and wide dynamic range. It is based on a duplexed path configuration with sharp out of band attenuation allowing improved isolation between the receiving and transmitting paths. BDA BLOCK DIAGRAM DESCRIPTION:
Refer to figure 1 for the following discussion. The BDA Downlink path receives RF signals from the base station and amplifies and transmits them to the subscriber. The BDA Uplink path receives RF signals from the subscriber and amplifies and transmits them to the base station. The Uplink and Downlink occupy two distinct frequency bands. For example, the PCS A frequency bands are as follows: 1850-1865 MHz for the Uplink and 1930-1945 MHz for the Downlink. Two diplexers isolate the paths and route each signal to the proper amplifying channel. A selectable Automatic Level Control (ALC) allows for output power limiting. A variable step attenuator provides 30 dB of attenuation in 2 dB steps. The use of these controls is covered in the OPERATION section, later in this document. Page 3 Figure 1 LNA LNA BLOCK DIAGRAM Page 4 ELECTRICAL SPECIFICATIONS:
Frequency Range Pass band Gain @ min attenuation Variable Step Attenuator Range
(2-dB steps) Pass band Ripple Noise Figure @+25C at max gain 3rd Order Intercept point Uplink Downlink Output Power @ 1dB Compression Uplink Downlink Isolation between Up/Down Link Input/ Output Impedance VSWR (Input/Output) Power Supply
: See Table 1
: 65 dB or 80 dB minimum
: 0-30 dB
: 1.5 dB typical
: 5.0 dB max
: +45 dBm typical
: +45 dBm typical
: +32 dBm (typ)
: +32 dBm (typ)
: 80 dB min
: 50 Ohms
: 1.5: 1 max
: 110VAC/0.67Amp
: 240VAC/0.34 Amp
: 50 to 60 Hz Page 5 Table 1 Downlink Frequency Ranges 1930-1945 MHz 1950-1965 MHz 1975-1990 MHz 1982.5-1990 MHz 1975-1982.5 MHz 1975-1980 MHz 1980-1985 MHz 1985-1990 MHz 1945-1950 MHz 1965-1970 MHz 1970-1975 MHz Uplink Frequency Ranges 1850-1865 MHz 1870-1885 MHz 1895-1910 MHz 1902.5-1910 MHz 1895-1902.5 MHz 1895-1900 MHz 1900-1905 MHz 1905-1910 MHZ 1865-1870 MHz 1885-1890 MHz 1890-1895 MHz Page 6 Frequency Band PCS A PCS B PCS C PCS C-1 PCS C-2 PCS C-3 PCS C-4 PCS C-5 PCS D PCS E PCS F MECHANICAL SPECIFICATIONS:
Size
: 11.2 x 9.7 x 6.0 inch
: (284.5 x 246.4 x 152.4 mm)
: N-type Female
: 13.5 Lbs. (6.2kg.) approx. RF Connectors Weight ENVIRONMENTAL CONDITIONS:
The unit is designed for indoor applications:
Operating temperature: - 20C to + 50C Storage temperature: - 50C to + 90C BDA CONNECTIONS The BDA AC power is accepted through a standard 3-wire male plug (IEC-320) with phase, neutral and ground leads. The AC power is wired to a high efficiency DC switching power supply which is CE and UL approved. The power supply runs the amplifiers and the Power On lamp. The metal enclosure of the BDA is connected to ground. A 9-pin D-Sub connector provides failure alarm output contacts (see diagram next page) as well as an optional 12 VDC (250mA) auxiliary output. The RF connections are made via two type N female connectors. The RF connector labeled BASE must be connected to the antenna pointing towards the base station. The RF connection labeled MOBILE must be connected to the antenna facing the area to be covered by the BDA. The RF connections must be made through cables with characteristic impedance of 50 ohms. The isolation between the base station antenna and the mobile antenna should be at least 12 dB higher than the BDA gain. Isolation less than this value can cause gain ripple across the band. Isolation equal to or less than the BDA gain will give rise to oscillations which will saturate the amplifiers and possibly cause damage to the BDA. Page 7 Figure 2 IN BUILDING REPEATER BDA Mechanical Outline Page 8 RF EXPOSURE WARNING In order to satisfy the FCC RF exposure requirements, the BDA/antenna installation must comply with the following:
The outdoor antenna (Yagi type or similar directional antenna) must be installed so as to provide a minimum separation distance of 0.3 meters (30 cm) between the antenna and persons within the area. (This assumes a typical antenna with gain of
[10.1 dBi, VSWR 1.5:1, Zo= 50 ohms, and a cable attenuation of between 1-10 dB). The indoor antenna (omni directional) must be installed so as to provide a minimum separation distance of 0.2 meters (20 cm) between the antenna and persons within the area. (This assumes a typical wide-beam type antenna with gain of 0-2 dBi, VSWR 2:1, Zo= 50 ohms, and a cable attenuation of between 1-10 dB). Page 9 BDA INSTALLATION DO NOT APPLY A.C. POWER TO THE BDA UNTIL CABLES ARE CONNECTED TO BOTH PORTS OF THE BDA AND THE ANTENNAS. 1. Mount the BDA on the wall with the RF connectors pointing DOWN. Using appropriate screws and anchors, attach the BDA to the wall at the four mounting holes on the side flanges. 2. Ensure that the isolation between the donor antenna and the service antenna is at least 12 dB greater than the BDA gain. (Use the higher of the Uplink and Downlink gains reported on the BDA test data sheet). 3. Connect the cable from the donor antenna to the BDA connector labeled BASE and the cable from the service antennas to the BDA connector labeled MOBILE. 4. Open the adjustment access panels on the sides of the BDA and verify that both of the ALC switches are in their factory preset ON positions. Close the panels. 5. Connect the AC power cord to the BDA and then to the power source. Verify that the Power ON lamp is illuminated. Installation of the BDA is now complete. To adjust the gain controls to suit the specific signal environment, refer to the next section of the manual. Page 10 BDA OPERATION Refer to figure 3 for adjustment access location and label. Variable Step Attenuator BDA gain can be reduced by up to 30 dB in 2 dB steps using the variable step attenuator (Figure 3). Gain adjustment is made with rotary switches accessible via the access door on the BDA enclosure. Arrows on the shafts of these switches point to the value of attenuation selected. BDA gain can be determined by subtracting the attenuation value from the gain reported on the BDA Test Data Sheet for that side of the unit. The attenuators are labeled for Uplink and Downlink. ALC (Automatic Level Control) To minimize intermodulation products, each amplifier in the BDA contains an ALC feedback loop. The ALC circuit senses the output power and limits it to the factory preset level of +25 dBm. ALC function is selected with an on/off toggle switch located on each amplifier and accessible via the adjustment access panels located on the sides of the BDA enclosure (Left, or BASE side is Downlink, right, or MOBILE side is Uplink). A red indicator lamp located on each amplifier illuminates when output power exceeds the ALC set point. The indicator is functional regardless of the position of the ALC switch. Units are shipped with the ALC switch in the ON position. If operation below the 25 dBm ALC set point is desired, BDA gain can be reduced by adjusting the variable step attenuator until the light goes off. Operation of BDA-PCS/X-1/1W-XX-A at minimum attenuation with greater than
-35 dBm average power incident for 65dB gain units and -50 dBm average power incident for 80dB gain units on either BASE or MOBILE port can cause damage to the BDA. Page 11 Figure 3 DOWNLINK 0 30 ON OFF DOWNLINK ALC Adjustment Access Panel and Label Page 12 DIAGNOSTICS GUIDE The BDA provides long term, care-free operation and requires no periodic maintenance. There are no user-serviceable components inside the BDA. This section covers possible problems that may be related to the installation or operating environment. a. Gain Reduction Possible causes: Bad RF cables and RF connections to antennas, Damaged antennas. b. Excessive Intermodulation or Spurious Possible causes:
Amplifier oscillation caused by insufficient isolation. The isolation between two antennas is given by the equation:
Isolation = 92.5 + 20 Log (F x D) Gt Gr Where:
F = frequency (GHz) D = separation (Km) Gt = transmit antenna gain (in the direction of the receive antenna). Gr = receive antenna gain (in the direction of the transmit antenna). For example, at the SMR frequencies, the antenna isolation at 100 m separation is about 71 dB for omni-directional antennas (0 dB gain). To increase isolation, the antennas should have higher directivity and must be pointed away from each other. c. Occasional Drop-out of some Channels Possible causes: One channel with very strong power dominates the RF output of the amplifier. Page 13