Frequency-Domain Perturbation
The Frequency-Domain Perturbation () study step is used for studying small oscillations about a biased solution (small-signal analysis).
This study step is useful for small-signal analysis (AC/DC), prestressed analysis (structural mechanics), and harmonic perturbation (fluid flow) types of analyses.
This study step is part of some two-step studies (see below).
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.
This study step is available for a variety of interfaces and licenses:
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As a study step with the AC Impedance, Stationary and AC Impedance, Time Dependent studies, which require the Batteries & Fuel Cells Module or the Electrodeposition Module.
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As a study step with the Prestressed Analysis, Frequency Domain study, which requires the Structural Mechanics Module, Geomechanics Module, MEMS Module, or Acoustics Module (depending on which physics interface you use it for).
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As a study step for the Small-Signal Analysis, Frequency Domain study, which requires the AC/DC Module or MEMS Module.
Harmonic Perturbation, Prestressed Analysis, and Small-Signal Analysis
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With the AC/DC Module, see Small-Signal Analysis of an Inductor, Application Library path ACDC_Module/Inductive_Devices_and_Coils/small_signal_analysis_of_inductor.
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With the Acoustics Module and AC/DC Module, see Loudspeaker Driver: Application Library path Acoustics_Module/Electroacoustic_Transducers/loudspeaker_driver.
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With the Batteries & Fuel Cells Module, see Electrochemical Impedance Spectroscopy in a Fuel Cell, Application Library path Batteries_and_Fuel_Cells_Module/Fuel_Cells/ac_fuel_cell.
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With the MEMS Module, see Frequency Response of a Biased Resonator—2D, Application Library path MEMS_Module/Actuators/biased_resonator_2d_freq.
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With the Structural Mechanics Module, see Bracket—Frequency-Response Analysis, Application Library path Structural_Mechanics_Module/Tutorials/bracket_frequency.