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3. TECHNICAL BRIEF
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Copyright © 2012 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
LG530G
11/87
Figure 3.3.2.1 QSC GSM receiver signal paths functional diagram
3.3.2 Receiver Part
There are two recommended GSM receiver path configurations; both are shown in Figure 3.3.2.1.
The configuration shown on top allows the GSM 850 and GSM 1900 bands to share the UMTS 850 and UMTS
1900 paths for US applications and uses four LNA inputs to support quad-band GSM operation.
The lower example uses two LNAs for quad-band GSM operation (one low band and one high band),
with two-way SAW filters between the antenna switch and the QSC inputs for each band type.
26page Figure 3.3.2.1
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g
LG530G
11/87
Figure 3.3.2.1 QSC GSM receiver signal paths functional diagram
3.3.2 Receiver Part
There are two recommended GSM receiver path configurations; both are shown in Figure 3.3.2.1.
The configuration shown on top allows the GSM 850 and GSM 1900 bands to share the UMTS 850 and UMTS
1900 paths for US applications and uses four LNA inputs to support quad-band GSM operation.
The lower example uses two LNAs for quad-band GSM operation (one low band and one high band),
with two-way SAW filters between the antenna switch and the QSC inputs for each band type.
Figure 3.3.2.1 QSC GSM receiver signal paths functional diagram
3.3.2 Receiver Part
G1800/1900
G850/900
U2100
U_HB
U_LB
G850
G900
G1800
G1800
Rx BPF
G1900
Rx BPF
G900
Rx BPF
Quad
D’convert
GSM Rx LO
QSC device
G850
Rx BPF
2-way SAW filters
to
/f
ro
m
o
th
er
p
at
hs
to
b
as
eb
an
d
ci
rc
ui
ts
M
N
LNA
LPF
REF & CLK
Generation
ADC_I
ADC_Q
from UMTS
receivers
LPF
J22
H22
G23
F23
LNA
MN = matching network
Antenna
A
nt
en
na
sw
itc
h
m
od
ul
e
M
N
G1900