User Guide

CCS Technical Documentation System Module and User Interface
Company confidential RH-20
Issue 1 10/2003 Nokia Corporation. Page 49
Figure 23: 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, acts as an error amplifier
- The signal from VCO is balanced, frequencies 3420 to 3980 MHz
- EGSM900 and GSM1800 low noise amplifier (LNA) are integrated.
The Helgo can be tested by test points only.
AFC function
AFC is used to lock the transceiver’s clock to the frequency of the base station.
Antenna
The RH-20 EGSM900/GSM1800/GSM1900 transceiver features an internal antenna.
EGSM
out
DCS/
PCS
out
EGSM
in
DCS/
PCS
in
Power
detector
EGSM
Power
control
DCS/PCS
Power
control
Mode
EGSM900
GSM1800
/
1900
EGSM900
GSM1800
/
1900
EGSM900
GS
M1800
/
1900