AE04B-A0279 Rev -- APPENDIXA: AMPLIFIER INSTALLATION
Document use is restricted to that described on cover
A-6
2. Connect a signal source to the null antenna. Make sure the frequency of the signal
source is well away from the BTS frequency, and set the source power level to 0
dBm. Set the spectrum analyzer to the signal source frequency and measure the
power level at the Donor antenna cable. The difference between the signal source
power and the spectrum analyzer power level reading is the antenna isolation in dB.
Record the values.
Signal Source Level ________ dBm
Spectrum Analyzer Level ________ dBm
Isolation ________ dB
The isolation value determines the maximum amount of gain allowed for either
downlink or uplink path. For the best stability of the system under all conditions, the
repeater gain in the uplink or downlink should be at least 10 dB less than the
isolation measured.
3. Initial Downlink Gain Setting
THE OUTPUT POWER OF THE EITHER PATH MUST NOT EXCEED THE
SPECIFIED RATING. IF THE SPECIFIED RATING IS EXCEEDED, THE UNIT
MAY NOT BE FCC COMPLIANT FOR SPURIOUS EMISSIONS.
Connect the spectrum analyzer to the NULL port of the repeater. Remember, the
power rating of the repeater is quite high and there is risk of exceeding the spectrum
analyzer maximum input. Place attenuators as required on the spectrum analyzer
input. Connect the Donor antenna to the DONOR port of the repeater.
The downlink output power of the repeater is equal to the input level measured in
Step 1 above, plus the repeater gain. Initially, set the repeater gain so that it meets
the isolation criteria specified in Step 2 without exceeding the output power specified
in Chapter 1, Table 1-1.
4. Initial Uplink Gain Setting
The uplink gain is completely dependent on the system design, and can only be
determined through drive testing. It is recommended that the gain be set to
minimum, and increased as required to meet system performance requirements.
5. Once the initial settings are made, drive testing is recommended to verify proper
coverage.
