I/Q Modulator Amplitude Balance And Phase Shift Tuning; Tuning Of Transmitter Power Levels - Nokia NSW-6 Series Technical Documentation Manual

NSW-6
Tuning, Flashing and NAM programming instructions PAMS Technical Documentation

3. I/Q Modulator Amplitude Balance and Phase Shift Tuning

This tuning is to adjust the DC–offset and phase offset of the I and Q–
modulators so that the system requirements for modulation accuracy will
be met.
– –Select Tuning ––> TX I / Q
– –Connect the spectrum analyzer to the antenna adapter or diagnostic
jig.
– –Use the following settings for spectrum analyzer in tuning:
– –Use "TX I DC Offset" and "TX I DC Offset" option to adjust CFR – 7.1
kHz to minimum.
– The amplitude difference between CFR and CFR – 7.1 kHz must be >
40 dB.
– –Use "Phase Offset " option to adjust CFR – 14.2 kHz to minimum
– The amplitude difference between CFR and CFR – 7.1 kHz must be >
40 dB.
– –Once the TX I, TX Q and phase shift are aligned, press SAVE button.

4. Tuning of Transmitter Power Levels

– This tuning is to adjust the output power level values of the radio unit
according to the system specification.
– This adjustment loads the power levels of the phone transmitter into
the EEPROM. When doing this, a pulse power meter or spectrum
analyzer must be used.
– Tuning targets are listed next page.
– –Set power supply voltage. See Note above.
– –Connect the pulse power meter or spectrum analyzer. Use attenua-
tor, if needed.
– – Settings for spectrum analyzer in power level tuning:
Page 10
– Set spectrum analyzer center frequency to 830.700 MHz.
– Set span 80 kHz
– Set Ref LVL 20 dB
– Set RBW and VBW 1 kHz
– Set sweep time 0.3 s
– Set span 0 Hz
– Set Ref LVL 30 dB
– Set Ref LVL offset and ––> Attenuation to Antenna Pad
– Set RBW and VBW 300 kHz
– Set sweep time 50 ms
– Set TRIG: SWEEP CONT, VIDEO –10 dBm
– Set marker at middle of slot.
– Check that spectrum analyzer frequency is correct
E Nokia Mobile Phones Ltd.
Issue 1 12/99