NSB–6
System Module
PAMS Technical Documentation
Page 39
Issue 1 06/2000
E
Nokia Mobile Phones Ltd.
RF Module
This RF module takes care of all RF functions of EGSM/GSM1900 dual-
band engine. RF circuitry is located on one side of the 8 layer tranceiver–
PCB. PCB area for the RF circuitry is about 15 cm2. The RF design is
based on the first dualband direct conversion RF–IC ”Hagar”. So there is
no intermediate frequency and that means the number of component is
much lower than before and there shall be much less interference prob-
lems than previously.
EMC emissions are taken care of using metallized plastic shield, which
screens the whole transceiver. Internal screening is realized with isolated
partitions. VCO is isolated in it’s own locker. PA and some surrounding
components are covered with metal can. The baseband circuitry is lo-
cated on the same side of the same board.
Environmental specifications
Normal and extreme voltages
Lithium–ion battery ( 1 cell )
Nominal voltage:
3.9 V
Lower extreme voltage:
0.85 x 3.9 = 3.31 V
Higher extreme voltage:
same as nominal
Absolute maximum voltage:
4.8 V
Software cut–off voltage:
3.1 V
(during TX burst)
Main Technical specifications
Maximum Ratings
Parameter
Rating
Battery voltage, idle mode
3.9 V
Regulated supply voltage
2.8 +/– 3% V
Voltage reference
1.5 +/– 1.5% V
Operating temperature range
–10...+55 deg. C
Absolute maximum battery voltage
4.8 V
RF Characteristics
Item
Values (EGSM / GSM1900)
Receive frequency range
925 ... 960 MHz / 1930 ... 1990 MHz
Transmit frequency range
880 ... 915 MHz / 1850 ... 1910 MHz
Duplex spacing
45 MHz / 80 MHz
Channel spacing
200 kHz
Number of RF channels
174 / 299
Power class
4 (EGSM900) / 1 (GSM1900)
Number of power levels
15 / 16
