LGE Internal Use Only
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3.9 RF Interface
E-GOLDvoice features a fully integrated constant-gain direct conversion receiver, i.e. there is no
interstage filter needed and the baseband level at the analogue IQinterface follows directly the RF
input level. Depending on the baseband ADC dynamic range, single- or multiple-step gain switching
schemes are possible.
An integrated, selfaligning, low-pass filter ensures the receivers to function under blocking and
reference interference conditions and avoids aliasing by baseband sampling. An automatic DC-offset
compensation is implemented and can be switched depending on the gain setting.
3. TECHNICAL BRIEF
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Figure 3-9-2. RF Module /SAW Filter interface
7
GSM_RX
NC
18
21
PGND
TX_EN
4
1
VBATT
VLOGIC
2
3
VRAMP
PCS_IN
19
6
PCS_RX
17
11
ANT
5
BS
GND1
8
9
GND2
10
GND3
GND4
12
13
GND5
GND6
14
15
GND7
GND8
16
GND9
20
GSM_IN
IN CASE OF GSM850/PCS1900
TO PART_NO SFSB0001301
PART_NO SFSB0001401
CHANGE THIS DUAL SAW FILTER
5.1nH
L405
1K
R405
39p
C409
39p
C411
2
G1
3
G2
5
G3
10
G4
I1
1
I2
4
9
O1_1
O1_2
8
O2_1
7
O2_2
6
B9310
FL401
C414
3p
3p
C416
SKY77517
U401
L404
18nH
C408
39p
3p
C413
C415
3p
C410
39p
VLOGIC
DCS_PCS_OUT
GSM_OUT
GSM_RXN
GSM_RXP
DCS_RXN
DCS_RXP
BS
TXON_PA
TX_RAMP