where NF1 and G1 are the NF and the gain of the optical block,
NF2 and G2 are the terms for the filters losses, NF3 is the NF of
theLNA, and givenNFtot theNFmeasured with the gainmethod
[38], the NF of the optical up-converter has been estimated in
46 dB for the X-band and 41 dB for the S-band.