Paper on Modeling RF Systems by Chen

no detail

is it for FET or BJT?

which is the best book and software for rf modelling?

I dont think there is exactly a best book....there is the manual of the Bsim3v3 were it is quiet good.
try to find information on academic researches like in BWRC at berkeley.

there are lots of good ieee papers on this topic!

thanks , generous guy