User Guide
Table Of Contents
- 7 - RF Description & Troubleshooting
- 1. RF Description and Troubleshooting
- 2. RF Implementation in NHL-12
- 3. Introduction to RF troubleshooting
- 4. Receiver Description and Troubleshooting
- 5. Transmitter Description and Troubleshooting
- 6. Additional Information on EDGE Troubleshooting
- 7. Synthesizer Description and Troubleshooting
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Issue 2 10/2004 COMPANY CONFIDENTIAL 23
Copyright © 2004 Nokia. All Rights Reserved.
NHL-12
7 - RF Description & Troubleshooting Nokia Customer Care
Figure 11:Power amplifier
■ RF ASIC Helgo
The RF ASIC features include:
• Package uBGA108
• Balanced I/Q demodulator and balanced I/Q modulator
• Power control operational amplifier, acting as an error amplifier
• Balanced signal from VCO, frequencies 3420 to 3980 MHz
• Integrated GSM850 and GSM1800 low noise amplifiers (LNAs)
• Helgo testing via test points only
■ AFC function
AFC is used to lock the transceiver’s clock to the base station frequency.
EGSM
out
DCS/
PCS
out
EGSM
in
DCS/
PCS
in
Power
detector
EGSM
Power
control
DCS/PCS
Power
control
Mode
GSM850
GSM1800/
1900
GSM850
GSM1800/
1900
GSM850
GSM1800/
1900