Comtech EF Data DD2401 VME - Manual (Page 19)

DD2401 VME L-Band Demodulator Card Installation & Operational Manual Theory of Operation
MN-VME2401 – Rev. B 3-1
Theory of Operation 3
3.0 Theory of Operation
The VME L-Band Demodulator Card is capable of receiving four L-Band signals between 950-
1750 MHz. The IF signals are then converted into data. The data is digitally filtered, passed
through the Viterbi FEC, differentially decoded and descrambled before it is sent to the RS422
terrestrial interface. The RS422 data from each demodulator can be retrieving from the rear
panels of each demodulator.
Rx
Baseband
Processing
Terminal
Remote
Port
M&C
Remote
Serial
Interfaces
Demodulator
RX RF
Equipment
Power Supply
+5 VDC
+12VDC
-12VDC
Terrestrial Data
Interface
Customer
Data
Terrestrial I/O
Modulator
Interconnect
Antenna
Demodulator Card
External
Referance
DD2401 VME Block Diagram
IF Input 950-1750 MHz
-25 to -55 dBm
Reference
Figure 3-1. DD2401 VME Demodulator Block Diagram