(2) Transmitter Part
Fig.3-2 Transmitter Block diagram
- 18 -
The Transmitter part contains CX74017 active parts, power amplifier module (PAM) and antenna
switch. The CX74017 active part consists of a vector modulator and offset phase-locked loop
block (OPLL) including down-converter, phase detector, loop filter and dual band transmit VCO
which can operate at either final RF output frequency. The RF GMSK outputs from the transmit
VCO are fed directly to the RF power amplifiers.
ANT
S/W
GSM
TXVCO
PAM(RF3110)
CX74017
Base
Band
Block
DCS : 1710 ~ 1785MHz
GSM : 880 ~ 925MHz
90
0
LF
TXIP
TXIN
TXQP
TXQN
PFD
/D2
/D1
X2
DCS
f
vco
/3
X2
f
TX
f
IF
f
LO
GSMSEL
DCSSEL
TXPA
TXRAMP
BANDSEL1
LMSP54AA-097
A. IF Modulator
The baseband converter(BBC) within the GSM chipset generates I and Q baseband signals for
the transmit vector modulator. The modulator provides more than 40dBc of carrier and unwanted
sideband rejection and produces a GMSK modulated signal. The baseband software is able to
cancel out differential DC offsets in the I/Q baseband signals caused by imperfections in the D/A
converters.
The TX-Modulator implements a quadrature modulator. The IF-frequency input signal is split into
two precise orthogonal carriers, which are multiplied by the baseband modulation signal IT/ITX
and QT/QTX. It is used as reference signal for the OPLL.
3. TECHNICAL BRIEF
Содержание G3100
Страница 32: ... 34 3 TECHNICAL BRIEF Figure 3 20 TX IQ Signal Figure 3 21 RX IQ Signal ...
Страница 40: ... 42 Figure 3 26 1 Voice band circuit diagram Headset Hands free kit part 1 3 TECHNICAL BRIEF ...
Страница 42: ... 44 Figure 3 27 AD6521 circuit diagram 3 TECHNICAL BRIEF ...
Страница 73: ... 75 4 3 8 Receiver RF Level Figure 4 1 Test Points of Rx Level 4 TROUBLE SHOOTING ...
Страница 74: ... 76 4 3 9 Transmitter RF Level Figure 4 2 Test Points of Tx Level 4 TROUBLE SHOOTING ...
Страница 81: ... 83 The Receiver part Circuit Diagram C203 C207 C206 4 TROUBLE SHOOTING ...
Страница 87: ... 89 R202 MIC201 R204 C204 C201 R208 R206 C208 Q203 4 TROUBLE SHOOTING ...
Страница 93: ... 95 Test SIM Connector Check J301 4 TROUBLE SHOOTING ...
Страница 97: ... 99 J201 R240 C234 L201 R241 4 TROUBLE SHOOTING U205 U203 U204 ...
Страница 101: ... 103 CN302 U203 U204 4 TROUBLE SHOOTING ...
Страница 102: ... 104 U205 4 TROUBLE SHOOTING ...
Страница 104: ...5 DISASSEMBLY INSTRUCTION 106 3 Detach the rest components as shown below Figure 5 3 Detaching the rest components ...
Страница 108: ...3 Press Start and Wait until Erase is completed 110 1 Press Start 2 Confirm completion 6 SOFTWARE DOWNLOAD ...
Страница 117: ... 119 9 PCB LAYOUT 9 1 Rear Part ...
Страница 118: ...9 2 Front Part 120 ...
Страница 124: ... 126 11 2 Standalone Test Equipment Setup GSM Test Equipment Power Supply PC JIG RS 232 Cable Phone 11 STAN ALONE TEST ...
Страница 134: ... 137 13 EXPLODED VIEW REPLACEMENT PART LIST 13 1 Exploded View ...