User Guide

Nokia Customer Care System Module
RH-37
Issue 1 07/04 Nokia Corporation Page 49
Figure 19: RF frequency plan
RF power supply configuration
All power supplies for the RF unit are generated in the UEM ASIC, which contains among
other functions six pieces of 2.78 V linear regulators (VR2 ... VR7), a 4.8 V switching reg-
ulator (VR1) and two 1.35V voltage references (VrefRF01 and VrefRF02).
The regulators are connected to the RF ASIC, except for VR7, which supplies the VCO. The
4.8V supply is required for the charge pump of the PLL to generate the tuning voltage for
the VCO.
The reference voltages are used as bias reference for the RF ASIC for the RX ADC (ana-
log-to-digital converter) reference.
All RF supplies can be checked either in Small Signal Chamber or in BB Chamber.
The used power supply configuration is shown in the block diagram below. Values of
voltages are given as nominal outputs of UEM. Currents are typical values.
G
SM900: 925-960 MHz
G
SM1800: 1805-1880 MHz
G
SM1900: 1930-1990 MHz
f
f
f/4
f/4
f
f
Helgo
f/2
f/2
PLL
3296-
3980
MHz
I-signal
Q-signal
RX
I-signal
Q-signal
TX
G
SM1900: 1850-1910 MHz
G
SM1800: 1710-1785 MHz
G
SM850: 824-849 MHz
G
SM900: 880-915 MHz
Buffer
VCTCXO
26 MHz
26 MHz
VCTCXO
AFC