I don't know exactly what you mean by intrinsic frequency (please elaborate), but answering your second question might answer it for you.

You don't need to save an expression in spectre, but if you do:

Code:

save m1:gm m1:cgs 

or just:

Code:

save m1 

(which will save all operating point data for a specific transistor), you can then compute gm/cgs in the calculator. If you can plot gm versus I, and cgs versus I, then in the calculator dividing the two will give gm/cgs versus I.

Whatever calculation you need to do to compute intrinsic frequency, can be done in this way.

Regards,

Andrew.

[quote author=James  link=1112889742/0#2 date=1112924296]Do you mean intrinsic frequency "gm*ro"? [/quote]
this is intrinsic gain.

ideally, it is the frequency that the gain of input current equals to output current.