RF is Radio Frequency that LNB can receive from a satellite. This would differ between a C-Band LNB, a Ku band standard LNB
IF is Intermediate Frequency
LO is local oscillating frequency
The relationship between all these parameters are RF + IF = LO or IF = RF – LO
Ref: http://www.polyphasemicrowave.com/datasheets/IRM0511B.pdf
The satellite signal at 12000 mhz, the local oscillator beats out a constant 10750 mhz. This generates an intermediate frequency of 1250, which is more easily conducted down the coax to the receiver for demodulation. Modulator applies desired modulation to RF or IF carrier wave and Demodulator extracts the original modulation from the RF or IF.
