Cell Receiver Check From Rf To Iq - Nokia 2125 Troubleshooting Manual

2125/2125i/2126/2126i/2128i (RH-71)
RF Description and Troubleshooting

Cell Receiver Check from RF to IQ

Use the following values to check the CDMA Cell Rx functionality from RF to IQ output.
1. Start Phoenix in Local Mode with only the Rx path turned on.
2. Inject a –75 dBm CW signal of 881.82 MHz (i.e. 300 kHz offset from 881.52 MHz
or 10 channels away).
3. Measure a 300 kHz tuning on the analyzer. You should see a typical -21 dBm IQ
tuning for CDMA Cell.
Cell I Q Output
dBm
Trace A
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
Centre: 300 kHz
Res BW: 3 kHz
5/5/2004 3:29:30 PM
Figure 11 shows the Cell spectrum with an inject tone at -75 dBm, as well as the IQ
output test points. Note that DC is present on the IQ output test points. All test points
should be approximately equal.
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1
Atten: 10 dB
Vid BW: 3 kHz
CellIQ.spt
Figure 10: Receiver IQ level on CDMA Cell band
©2005 Nokia Corporation
Span: 200 kHz
Sweep: 100 ms
HP8595E
Company Confidential
1 Trace A
302 kHz
-21.2500 dBm
ISSUE 1 08/2005