A new approach is presented in this paper to help the modeling of complex a
ctive microwave devices like field-effect transistors. This hybrid method c
ouples an electromagnetic three-dimensional simulator to characterize the e
xtrinsic part and a circuit software to introduce the contribution of the c
omponent intrinsic part. The interests of such approach are diverse and are
discussed in this paper, Theoretical linear and nonlinear results are comp
ared with measurements and shove good agreements.