Fourier Transform
Purpose
Perform Fourier transform on input signal
Library
Control / Filters
Description
This block calculates the Fourier transform of a periodic input signal. The sample time, the fundamental frequency and the harmonic order(s) can be specified. The outputs of the block are the magnitude and phase angle of the specified harmonics.
If you specify more than one harmonic, the outputs will be vectors with the corresponding width. Alternatively you can specify a single harmonic and feed a vector signal into the block.
Parameters
- Sample time
A scalar specifying the sampling period or a two-element vector specifying the sampling period and offset, in seconds \((\mathrm{s})\). See also the Discrete-Periodic sample time type in section Sample Times. If a sample time of
0is specified, a continuous implementation based on the Moving Average block is active. The Discrete-Periodic implementation can potentially force a variable-step solver to take small integration steps. This may slow down the simulation. The default value of this parameter is0.- Fundamental frequency
The fundamental frequency of the periodic input signal in hertz \((\mathrm{Hz})\).
- Harmonic orders n
A scalar or vector specifying the harmonic component(s) you are interested in. Enter
0for the dc component,1for the fundamental component, etc. This parameter should be scalar if the input signal is a vector.
Probe Signals
- Input
The input signal.
- Magnitude
The first output signal, i.e. the computed magnitude.
- Phase
The second output signal, i.e. the computed phase angle, in radians.