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
- BACK TO MAIN PAGE
Issue 2 10/2004 COMPANY CONFIDENTIAL 13
Copyright © 2004 Nokia. All Rights Reserved.
NHL-12
7 - RF Description & Troubleshooting Nokia Customer Care
4. Receiver Description and Troubleshooting
■ Receiver
Each receiver path is a direct conversion linear receiver. From the antenna, the received RF
signal is fed to a front end module where a diplexer first divides the signal into three separate
paths according to the band of operation: either lower GSM850 or upper GSM1800 or
GSM1900 path.
Most of the receiver circuitry is included in Helgo.
■ Rx front-end
The front-end features include:
• Antenna 50 ohm input
• Rx GSM850, GSM1800 and GSM 1900 50 ohms inputs
• Txs single 50 ohm input
• 3 control lines from the Helgo
Figure 7: Front-end