C-band frequency translations – Comtech EF Data MIDAS Version 4.X Basic Configuration User Manual
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MIDAS 4.2 Basic Configuration, Rev. 1
A–8 Maintenance
Menu
C
C
-
-
B
B
a
a
n
n
d
d
F
F
r
r
e
e
q
q
u
u
e
e
n
n
c
c
y
y
T
T
r
r
a
a
n
n
s
s
l
l
a
a
t
t
i
i
o
o
n
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s
The following parameters are configurable for C-Band:
Satellite – Downlink Factor
Equivalent to LNB LO (Low Noise Block Converter Local Oscillator
frequency). Common C-Band LO’s include 5.15 GHz and 5.76 GHz.
Satellite - Translation
Frequency difference between the Transponder TX Center and the
Transponder RX Center (C-Band Default = 2.225 GHz).
Satellite High-Side Injection
High-side injection is where the LNB LO frequency is higher than the
RX RF frequency and the difference is used to convert to L-Band.
C-Band default = ON/High side injection).
Transponder – TX Center
TX Center frequency the Ku transponder.
Transponder – RX Center
RX Center frequency the Ku transponder.
Figure A-1 exhibits:
• A 36 MHz Ku-Band transponder with the default case of high-side in-
jection, which results in frequency inversion.
• If low-side injection is specified, use the Ku-Band example, substitut-
ing C-Band frequencies in the example.
• A relationship between the downlink RF frequencies and the corre-
sponding L-Band IF frequencies for the first transponder of the satel-
lite.
Note: There is a 2 MHz guard band at the lower and upper edges of the transponder,
so the C- and L- Bands display 40 MHz of bandwidth (FC
± 20 MHz).