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7.1 Radio Frequency (RF) Block Diagram
Antenna
RX 900
RX 1800
( + Filter)
TX 900
TX 1800
Diplexer
switch
The GMSK modulated 900 MHz / 1800 MHz signal received by the antenna is downconverted into the baseband
via an intermediate frequency of 282 MHz. In the transmit direction the digitally GMSK-modulated baseband signal
is modulated to the transmit frequency in the 900 MHz / 1800 MHz bands by means of a modulation loop and the
dual power VCO.
The radio part mainly consists of the RF Synthesizer, Receiver (RX), Transmitter (TX), power amplifiers,
diplexer/switch, antenna connector with integrated switch and antenna.
SECTION 7
DIAGRAMS
EGSM
LNA
EGSM
EGSM 925 - 960 MHz
28
13
26
29
14
BPF2
BPF4
DCS
LNA
DCS
DCS 1805 - 1880 MHz
1
11
15
2
12
BPF5
BPF1
PMB 2333
RX
DUAL RF VCO
TX
DUAL TX VCO
EGSM
PA-Module
Matching
880..915 MHz
GSM
DCS
PA-Module
Matching
1710..1785 MHz
DCS
PMB 2411
20
21
282 MHz
PGC
IF Filter
8
17
18
9
8
9
BPF3
6
7
GSM LO
1207 - 1242 MHz
DCS LO
1523 - 1598 MHz
GSM
1
3
PD1
.
5
RF1
DCS
3
VBB2
8
VBB1
GSM : 1162 - 1197 MHz
DCS : 1521 - 1596 MHz
23
LO
21
RF
GSM 900 : R=4
DCS 1800 : R=6
1
GSM : Fpd = approx. 140 MHz
R
DCS : Fpd = approx. 95 MHz
LPF
ϕ
19
CP
1
N
13
SERCK
14
GSM 900 : N=2
SERDA
DCS 1800 : N=2
15
PGC_TX_STR
PMB 2251
20
LPF
43
48
0°
1
2
90°
282 MHz
LPF
37
42
564 MHz
IF
10
SERDA
VCO
11
SERCK
12
PGC_TX_STR
18
PD2
VC - TCXO
16
Dual PLL
RF2
13
RI
PMB 2346
8
SYN_STR
9
SERDA
10
SERCK
SYN2V8
GSM AND DCS : 558, 564 and 570 MHz
MO
25
CR
11
27
IF
TX IF Filter
CN
9
6
E
90°
∑
0°
TXPLL2V8
RX IP
RX IN
Rx
RX QN
RX QP
REF_13MHz to BB
13 MHz
AFC
RF2V8
1
TX IN
2
TX IP
Tx
3
TX QP
4
TX QN
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