Documentation

This is machine translation

Translated by Microsoft
Mouseover text to see original. Click the button below to return to the English verison of the page.

Note: This page has been translated by MathWorks. Please click here
To view all translated materals including this page, select Japan from the country navigator on the bottom of this page.

What Is a Frequency Response Model?

Frequency response describes the steady-state response of a system to sinusoidal inputs.

For a linear system, a sinusoidal input of frequency ω:

u(t)=Ausinωt

results in an output that is also a sinusoid with the same frequency, but with a different amplitude and phase θ:

y(t)=Aysin(ωt+θ)

Frequency response G(s) for a stable system describes the amplitude change and phase shift as a function of frequency:

G(s)=Y(s)U(s)|G(s)|=|G(jω)|=AyAuθ=Y(jω)X(jω)=tan1(imaginary part of G(jω)real part of G(jω))

where Y(s) and U(s) are the Laplace transforms of y(t) and u(t), respectively.

Frequency Response Model Applications

You can estimate the frequency response of a Simulink® model as a frequency response model (frd object), without modifying your Simulink model.

Applications of frequency response models include:

Was this topic helpful?