User Guide

Min Typ Max Unit

Phase 95 100 110 dB

Tx power level tuning (GSM)

Context

Because of variations at IC process and discrete component values, the actual transmitter RF gain of each

phone is different. Tx power level tuning is used to find out mapping factors called 'power coefficients’. These

adjust the GSM transmitter output power to fulfill the specifications.

In dual or triple band phones, the power level tuning is made for both high and low PA Modes (Power Amplifier

Mode) in the GSM850/GSM900 bands but only for high PA mode in GSM1800/GSM1900 bands

For EDGE transmission the bias settings of the GSM PA are adjusted in order to improve linearity. This affects

the PA gain and hence the power levels have to be aligned separately for EDGE transmission.

Tx power level tuning has to be performed on all GSM bands.

Steps

1. Connect the phone to a spectrum analyzer.

2. Start Phoenix service software.

3. From the "Operating mode" dropdown menu, set mode to "Local".

4. From the Tuning menu, choose GSM -> Tx Power Level Tuning.

5. Set the spectrum analyzer for power level tuning:

Frequency channel frequency (881.6MHz GSM 850, 897.4MHz

GSM900, 1747.8MHz GSM1800, 1880MHz

GSM1900)

Span 200 kHz

Sweep time 3s

Trigger Video triggering: Free run

Resolution BW 3 kHz

Video BW 3 kHz

Reference level offset sum cable attenuation with module jig

attenuation

Reference level 33dBm

A power meter with a peak power detector can be also used. Remember to take the attenuations in the

account!

RM-10;RM-24

RF Troubleshooting and Manual Tuning Guide Nokia Customer Care

Issue 1 COMPANY CONFIDENTIAL Page 7 –37