Samsung SGH-T408, Руководство по обслуживанию

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4-3 Block Diagrams
4-2-1 RF Transmit Part
VCTCXO
(U102)
EGSM TX
880 ~ 915 MHz
(CH62 :
902.4 MHz)
DCS TX
1710 ~ 1785 MHz
(CH698 :
1747.4 MHz)
Antenna
S/W
(U107)
RF
Conector
(CN1)
VP40578
(U406)
S
D
ATA
SCLK SENB
PDNB
PD
LPF
Si4200 (U104)
I Q
Dual P
A
M
(U106)
RF
PLL
Si4133-T (U103)
AFC
+VBA
TT
Txpo
w
e
r
from U406
2.8VRFVCC
8
2.8VTX
TXEN2
from U406
VC1
VC2
Ant.
S/W
Control
Circuit
BAND Selection
VREG
BAND Selection - GSM :
Lo
w
- DCS :
High
<EGSM> 1279 ~ 1314 MHz <DCS> 1327 ~ 1402 MHz
-6dBm @ 1301.4 MHz (G) -9dBm @ 1364.4 MHz (D)
21
1
53
9
11
7 1
24 25
5 6 7 8
31
1
3
7
26,27
23,24 12,13
9,10
IF
PLL
9
/2
<EGSM> 880~895 MHz :
798 MHz
895~900 MHz :
790 MHz
900~915 MHz :
798 MHz
<DCS> 766 MHz
-6dBm @ 798 MHz -9dBm @ 766 MHz
1
2
3
VC2
VC1
Tx(GSM) Tx(DCS)
Rx
L
L H
H LL
TXEN2 Txpo
w
e
r
2
1