MITSUBISHI FA9M0476 Repair Manual

Level 3 Service Manual
COSMO
3.c.1 Reception Block Diagram.
Mecha
GSM SUPPLY
SWFL 50045 MHz
FL 504TR504FL 503
FILTER
225
MHz
GSM RX : 925 - 960 MHz45MHz
SW700
270MHz
DCS RX : 1805 - 1880 MHz
TR503FL 502
DCS SUPPLYFL 501
LNA
1/21/2
GSM & DCS :1080MHzGSM & DCS : 540MHz
RX
I,Q
IF1/21/2DEMOD
CLKPLL
90MHz
SDATA
SLEIC602
RFRX GSM : 1150 - 1185MHz
PLLRX DCS : 1580 - 1655MHz
TCXO
13MHz
Description of Reception Block Diagram.
E-GSM band (925-960 MHz).
Incoming RF signal from aerial is filtered and switched to the RX GSM path through SW700 . The
signal is filtered by FL504 , before being amplified by TR504 , and is further filtered by FL503. Then,
the signal input sent to RF-IC (IC600) in a first mixer stage. The RF signal (925-960 MHz) is mixed
with the RF-PLL Frequency (1150-1185 MHz) coming from IC601 (PLLs & VCOs). For the channel 1,
the output signal of the mixer is 225 MHz (1150 - 925 = 225 MHz), and is filtered by FL500.
DCS band (1805-1880 MHz).
Incoming RF signal from aerial is filtered and is switched to the RX DCS path through SW700 . The
signal is filtered by FL501 , before being amplified by TR503 , and is further filtered by FL502. Then,
the signal input to RF-IC (IC600) in a first mixer stage. The RF signal (1805-1880 MHz) is mixed with
the RF-PLL Frequency (1580-1655 MHz) coming from IC601 (PLLs & VCOs) via IC602 (RF-VCO).
For the channel 1, the output signal of the mixer is 225 MHz (1805 Mhz-1575 MHz = 225 MHz), and
is filtered
by FL500.
For the E-GSM and DCS bands.
The first intermediate frequency is 225 MHz. Then, this frequency is filtered by FL 500 before input to
the second mixer stage. The first IF (225 MHz) is mixed with the 270 MHz (Fixed Frequency PLL
540 /2 = 270 MHz), to a second IF 45 MHz. The second IF is demodulated to Base Band (IC300) I/Q
phase demodulated signals. RF-IC (IC600) provides automatic gain control.
IC600 includes a quadrature demodulator. The second IF signal (45 MHz) is demodulated to I, Q
balanced signals for One-C.
Version AMitsubishi Electric Telecom Europe S.A.
Date: 04/00ZA le Piquet 35370 Etrelles
Phone: +33 2 99 75 71 00
12/29
Fax: + 33 2 99 75 71 47