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 side-
band. 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. A quadrature mixer upconverts the differential
I/Q signals with the IFLO to generate a SSB IF signal, which is filtered and used as the reference input
to the OPLL. The IFLO frequency is generated between 766 and 896 MHz and internally divided by 2
to generate the quadrature LO signals for the quadrature modulator, resulting in an IF between
383MHz and 448 MHz.
3.3.1. IF Modulator
-16-
3.3.2. OPLL
The OPLL consists of a feedback mixer, a phase detector, a loop filter, and a fully integrated TXVCO.
The TXVCO is centered between the DCS 1800 and PCS 1900 bands, and its output is divided by 2 for
the GSM 850 and E-GSM 900 bands. The RFLO frequency is generated between 1272 and 1483 MHz.
To allow a single VCO to be used for the RFLO, high-side injection is used for the GSM 850 and
E-GSM 900 bands, and low-side injection is used for the DCS 1800 and PCS 1900 bands. Low-pass
filters before the OPLL phase detector reduce the harmonic content of the quadrature modulator and
feedback mixer outputs. The cutoff frequency of the filters is programmable with the FIF[3:0] bits in
register 04h. The OPLL requires no external duplexer to attenuate transmitter noise and spurious signal
s in the receive band. Additionally, the output of the transmit VCO (TXVCO) is a constant-envelope
signal which reduces the problem of spectral spreading caused by non-linearity in the PA.
Figure 3. RF Transmit Block
Φ
DET
Φ
DET
÷
2
÷
2
÷
1
÷
1
÷
2
÷
2
IF PLL
IF PLL
I
Q
Baseband
(TI)
U101
IOTA
+
U102
Calypso
Baseband
(TI)
U101
IOTA
+
U102
Calypso
PA_BAND
VC1,VC2,VC3
RFOG
RFOD
EGSM
DCS/ PCS
RF PLL
RF PLL
D
I
P
D
I
P
DCS
FL801
Antenna Switch
PCS
EGSM
Si4205 (U803)
PAM RF3146 (U804)
PA
PA
Triple Buffer
Triple Buffer
VC1,VC2,VC3
Содержание L1100
Страница 1: ...Service Manual Model L1100 Service Manual L1100 P N MMBD0032801 Date June 2004 Issue 1 0 ...
Страница 31: ... 30 Figure 14 Power Supply Scheme ...
Страница 46: ... 45 Figure 25 CLC344E Camera Chip Circuit ...
Страница 49: ... 48 Figure 28 Camera Module Circuit MAIN BOARD FPCB ...
Страница 62: ...4 9 Microphone Trouble 61 Circuit Diagram ...
Страница 82: ... 81 U602 FPCB CN2 1 3 U601 5 4 Test Points 1 20 2 19 ...
Страница 88: ...Checking ANT SW Mobile SW 2 Rx pass continued 87 SW801 ANT Pin 2 VC2 SW801 RF Pin 7 VC1 Pin5 VC3 U801 FL801 ...
Страница 97: ...Checking ANT SW Mobile SW 2 Tx pass continued 96 Pin 2 VC2 SW801 RF Pin 7 VC1 Pin5 VC3 U801 FL801 SW801 ANT ...
Страница 98: ...5 1 Disassembly 5 ASSEMBLY INSTRUCTION 97 2 1 1 2 ...
Страница 99: ...98 1 2 3 2 1 ...
Страница 100: ... 99 1 2 3 ...
Страница 101: ... 100 ...
Страница 103: ...6 2 Download Procedure 1 Execute Fluid_GUI exe and select Erase Program flash menu 104 ...
Страница 104: ...2 Click the Add button Then choose m0 file which is going to download 105 ...
Страница 106: ...4 Press Global Settings menu Choose a correct serial port and set the configuration as below 107 ...
Страница 108: ...6 Wait for downloading to be finished 109 ...
Страница 125: ... 127 9 PCB LAYOUT ...
Страница 126: ... 128 9 PCB LAYOUT ...
Страница 129: ... 131 12 EXPLODED VIEW REPLACEMENT PART LIST 12 1 EXPLODED VIEW ...