The Frequency Domain Perturbation (
) study step is used for studying small oscillations about a biased solution (small-signal analysis).
When this study step is added to the Model Builder as part of a two-step study, the first step is usually a Stationary study step that computes the stationary (or bias) solution. The second step is the
Frequency Domain Perturbation step, which computes a perturbed solution of the linearized problem around the linearization point (or bias point) computed in the first step. The settings are the same as those for the
Stationary and
Frequency Domain nodes.