User Guide

PAMS Technical Documentation Service Software
NSB-5
Issue 1 03/01 Nokia Mobile Phones Ltd. Page 39
phase difference.
The TX I/Q tuning is performed in the following seven steps:
1. Connect the GSM/PCS signal tester or spectrum analyzer to the phone antenna con-
nector. When using spectrum analyzer: The recommended spectrum analyzer settings
are: Span 200 kHz, Resolution Bandwidth 10 kHz, Video Bandwidth 1 kHz, Sweep
500 ms, Input Attenuation 30 dB.
2. Select PCS band on the GSM/PCS signal tester or GSM/PCS Spectrum analyzer. Select
the GSM band in WinTesla (Product, Band menu).
3. Select the menu Tuning, Tx I/Q.
4. Choose the option EEPROM values to tune the TX I/Q values in the phone, and select
the OK button.
5. Adjust the TX I DC Offset and TX Q DC Offset stepwise until the carriers are suppressed
as much as possible (refer to the drawing below). When tuning, slowly adjust the values
step-by-step.
6. Adjust the Amplitude difference and the Phase difference stepwise until the side
bands are suppressed as much as possible (Refer to the drawing above). When tuning,
slowly adjust the values step-by-step.
7. Store the selected values to the phone by pressing the OK button.
During tuning, proceed as follows:
-Take care not to damage sensitive measuring instruments with excessive RF power.