User Guide

System Module LG4 and Grip Module LS4 CCS Technical Documentation
Page 46 ¤Nokia Corporation Issue 2 11/02
Figure 25: Gain control of E-GSM900
18+46=64
18+36=54
18+26=44
18+16=34
18+6=24
18-4=14
-7+6=--1
-7-4=-11
Receiver chain
gain
[ dB ]
64
54
44
34
24
14
-1
-11
RF signal
[ dBm ]
-110 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0
-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0
LNA gain = +18dB ( E-GSM900 ) LNA gain = -7dB ( E-GSM900 )
DtoS gain = ? dB DtoS gain = ? dB
Accurate gain control region
ADC input
voltage
[ mV
p-t-p ]
RF signal
[ dBm ]
+
4
6
d
B
+
3
6
d
B
+
2
6
d
B
+
1
6
d
B
+6dB
-
4
d
B
+
6
dB
-
4
d
B
-110
Accurate RSSI requirment range