Antenna Troubleshooting; Introduction To Wlan Rf Tuning; Tx Iq Tuning - Nokia RX-44 Service Manual

RX-44
RF Troubleshooting and Tuning

Antenna troubleshooting

The device uses a common antenna for Bluetooth and WLAN. If fault is not found after TX and/or RX
troubleshooting then check antenna by doing SB-7 test.
If it does not work check detailed instructions for antenna troubleshooting from Bluetooth troubleshooting
in BB Troubleshooting and Manual Tuning Guide.

Introduction to WLAN RF tuning

Phone WLAN RF is tuned in production. There is no reason to do the re-calibration unlessoOne or more of the
RF components is changed.
Note:
RF calibration is always performed with the help of a product-specific module jig, never with an RF coupler.
Using an RF coupler in the calibration phase will cause a complete mistuning of the RF side.
Cable and adapter losses RF cables and adapters have some losses. They have to be taken in account when
the phone is tuned.
As all the RF losses are frequency dependent, the user have to be very careful and understand the
measurement setup. In the following table there are RF attenuations of the Rf cable CA-58 RS connected to
RF connector on PWB.:
Freq. (MHz)
2400
2440
2480
Note: XRS-6 RF cable should be connected to SMA connector of CA-58RS cable.

Tx IQ tuning

Context
The Tx path branches to I and Q signals at the RF I/Q modulator. Modulator and analog hardware located
after the modulator cause unequal amplitude and phase disturbance to I and Q signal paths. Tx IQ tuning
balances the I and Q branches.
Steps
1. Connect the phone to a measurement equipment.
2. From the dropdown menus, set "Operating mode" to "Local"
3. From the Tuning menu, choose "WLAN Tx I/Q Tuning"
4. Set PCV value to 160 and Calibrate all channels on.
5. Click Start.
Issue 1
Attn. (dB)
0.4
0.4
0.4
COMPANY CONFIDENTIAL
Copyright © 2007 Nokia. All rights reserved.
Tolerance (dB)
0.5
0.5
0.5
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