Comtech EF Data CST-5005 - Manual (Page 84)

Theory of Operation CST-5005 C-Band Satellite Terminal
5–14 Rev. 1
5.5 Down Converter
The function of the down converter is to convert the C-band signal from the LNA to a
70 MHz IF signal for use in the modem.
Refer to Figure 5-7 for a functional block diagram of the down converter.
3625 TO 4200 MHz
-36 TO -21 dBm
SMA FEMALE
RF INPUT
DOWN CONVERTER
FROM
SYNTHESIZER
FROM IFLO
PHASE
EQUALIZER
ATTENUATOR
SMA FEMALE
70 MHz (+/-18 MHz)
P = +11 dBm
2nd IF OUTPUT
+4 dBm
SMA FEMALE
1112.5 MHz
+13 dBm
SMA FEMALE
LO INPUT
LO INPUT
Figure 5-7. Down Converter Block Diagram