User's Manual

Test Set Calibration68P64115A18–1
Mar 2003
1X SC 4812T Lite BTS Optimization/ATP Software Release R2.16.1.x
DRAFT
3-79
Calibrate Test Cabling Using Signal Generator & Spectrum Analyzer
Refer to Figure 3-23 and follow the procedure in Table 3-27 to calibrate
the TX test cable configuration for all BTSs or the RX ATP test cable
configuration for BTSs with duplexed TX/RX using the signal generator
and spectrum analyzer. Refer to Figure 3-24 and follow the procedure in
Table 3-28 to calibrate the test cable configuration for non–duplexed RX
using the signal generator and spectrum analyzer.
TX and Duplexed RX Cable Calibration
Table 3-27: Calibrate TX/Duplexed RX Test Cabling using Signal Generator & Spectrum Analyzer
Step Action
1 Connect a short test cable between the spectrum analyzer and the signal generator as shown in
Figure 3-23, detail “A” (top portion of figure).
2 Set signal generator to 0 dBm at the customer frequency of the 869.7–893.31 MHz band for North
American cellular and 1930–1990 MHz band for North American PCS.
3 Use spectrum analyzer to measure signal generator output and record the value for the detail “A”
setup.
4 Change the test setup to the one shown in detail “B” (lower portion of Figure 3-23), to measure cable
output at customer frequency (869.7–893.31 MHz band for North American cellular and 1930–1990
MHz for North American PCS) and record the value measured using the detail “B” test setup.
5
Calibration factor = (value measured with detail “A” setup) – (value measured with detail “B” setup)
Example: Cal factor = –1 dBm – (–53.5 dBm) = 52.5 dB
NOTE
The short cable is used for calibration only. It is not part of the final test setup. After calibration is
completed, do not re-arrange any cables. Use the test cable configuration as–is to ensure test
procedures use the correct calibration factor.
Figure 3-23: Cal Setup for TX/Duplexed RX Test Cabling Using Signal Generator & Spectrum Analyzer
50 OHM
TERMINATION
30 DB
DIRECTIONAL
COUPLER
Spectrum
Analyzer
Signal
Generator
A
Spectrum
Analyzer
40W NON–RADIATING
RF LOAD
B
SHORT TEST CABLE
Signal
Generator
THIS WILL CONNECT TO THE POWER METER OR
COMMUNICATIONS SYSTEM ANALYZER DURING TX
CALIBRATION AND TO THE COMMUNICATIONS
SYSTEM ANALYZER DURING TX AND RX ATP TESTS.
SHORT
TEST
CABLE
SECOND TX TEST CABLE
FOR TX CAL AND ATP
20DB 20 W IN–LINE
ATTENUATOR FOR
1.9 GHZ
THIS WILL CONNECT TO THE BTS TX
ANTENNA CONNECTOR DURING TX
CALIBRATION AND TO THE TX/RX ANTENNA
CONNECTORS DURING ATP TESTS.
TX TEST
CABLE
RX TEST CABLE
FOR RX ATP TEST
OR