Aliased Sweep

In this example, the Chirp block outputs a chirp signal containing negative frequencies. The Time Scope displays the signal output in the time domain, and the Spectrum Analyzer displays the spectrogram in the frequency domain.

Set the Target frequency to 275 and specify Target time equal to Sweep time. The output chirp of this example might not behave as you expect because the sweep contains frequencies greater than half the sampling frequency (200 Hz). If you unexpectedly get a chirp output with a spectrogram resembling the one following, your chirp's sweep might contain frequencies greater than half the sampling frequency.

Run the model to see the signal output and the spectrogram.