rfic mmic
Momentum is an electromagnetic simulation tool. You can read more about it on the HP website.(currently Agilent) Momentum runs, for example, EM simulations to extract parameters for an inductor using Green's functions. Since i am not a CAD person, this is as far as i would go. it can also run some structural simulations but not really designed for that.
I was a little vague, I apologize. When i say structural simulation, i mean, hp's HFSS (high frequency structural simulator) or the like. This would be an essential part of designing microstrip lines or waveguides for MMIC design. other tools can be CST Microwave Studio, FEMLAB, Genesys Suite, Microwave Office that have some if not all the functionality.
For terminology, MMIC refers to "millimeter wave" integrated circuits as far as i know. At least, this is what is meant by MMIC currently.
30 GHz=1cm.
and anything above that is usually referred to as being in the MMIC domain. The division is sort of fuzzy, since you can have 40GHz circuits on cmos these days.