Comtech EF Data MIDAS Version 4.X NMS Configuration - Manual (Page 149)

MIDAS 4.X NMS Configuration, Rev. 6
Frequency Translation A-17
I I F F t t o o 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 I I n n v v e e r r s s i i o o n n
Normally, there is no frequency inversion between the IF (70 MHz) and the RF (C-Band or
Ku-Band). If there were a frequency inversion between IF and C-Band, the IF to
C-Band conversion is altered slightly: the IF Frequency is subtracted instead of added. In
the example of a C-Band frequency of 3.7285 GHz, the IF frequency would be 61.5 MHz,
8.5 MHz below the IF center of 70 MHz.
RF = Transponder RX Center + 70 MHz – IF
(3720 + 70 – 61.5 = 3728.5 MHz)
Also, in this case, the IF to L-Band formula changes, and the conversion factor is:
Conversion Factor = 5150 MHz - Transponder RX Center - 70 MHz
(5150 MHz - 3720 MHz - 70 MHz)
Conversion Factor = 1360 MHz
The usage of the conversion factor is:
L-Band = ConversionFactor + IF Freq
or
IF = L-band – ConversionFactor