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LGE Internal Use Only
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. TECHNICAL BRIEF
Figure 34. Receiver Block Diagram of S-GOLDradio
The constant gain direct conversion receiver contains all active circuits for a complete receiver chain for
GSM/GPRS/EDGE (see Figure 30). The GSM850/900/DCS1800/ PCS1900 LNAs with balanced inputs are fully
integrated. No inter-stage filtering is needed. The orthogonal LO signals are generated by a divider-by-four for
GSM850/900 band and a divider-by-two for the DCS1800/PCS1900 band. Down conversion to baseband
Figure 33 TX IQ
3.20. Receiver part
R113
4.7K
R111
390K
R114
100K
P3
VRAMP
T5
VDET
TX1
V3
W3
TX2
T_OUT3
A18
J10
PAEN
M3
PAMODE
U5
W2
RX1
RX1X
V1
U1
RX2
T1
RX2X
RX3
R1
P1
RX3X
RX4
N1
RX4X
M1
PABIAS
R3
R4
PABS
M0
H3
J3
M1
M10
F4
M2
G4
H4
M7
M8
G3
J4
M9
FE1
N4
P5
FE2
TP105
C135
1u
FB180
0.1u
PA_EN
PA_EN_LED
VBAT
C129
UART_BT_RTS
PCS1900_RXN
DCS1800_RXP
DCS1800_RXN
GSM900_RXP
GSM900_RXN
GSM850_RXP
GSM850_RXN
TX_RAMP
PCS1900_RXP
TXLB
TXHB
BAT_ID
RF_TEMP
REMOTE_ADC
PA_BAND
PA_MODE
VC1
VC2