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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NHL-12
Nokia Customer Care 7 - RF Description & Troubleshooting
22 COMPANY CONFIDENTIAL Issue 2 10/2004
Copyright © 2004 Nokia. All Rights Reserved.
5. Transmitter Description and Troubleshooting
The transmitter consists of two final frequency IQ-modulators and a power amplifier (separate
ones for the lower and upper bands), and a power control loop. The IQ-modulators are integrat-
ed in Helgo, as well as the operational amplifiers of the power control loop. The two power am-
plifiers are located in a single module with a power detector. In the GMSK mode, the power is
controlled by adjusting the DC bias levels of the power amplifiers.
■ Transmitter characteristics
■ Power amplifier
The power amplifier features include:
• 50 ohm input and output, GSM850/1800/1900
• internal power detector
• EDGE mode
Item Values (GSM850/1800/1900)
Type Direct conversion, nonlinear, FDMA/
TDMA
LO frequency range 3296...3396 MHz/3420...3570 MHz/
3700...3820 MHz
Output power GMSK 33/30/30 dBm
8-PSK 27/26/26 dBm
Gain control range min. 30 dB
Phase error (RMS/peak), GMSK
EVM (RMS/peak), 8-PSK
5 deg./20 deg. peak
10%/30%