Aliasing effect

The aliasing effect aliasing effect concerns the sampling of a continuous function that is not bandwidth-limited to less than fc. In this case, all the power spectral density corresponding to a frequency greater than fc is "shifted" and disturbs lower frequency items.

The following diagram illustrates the problem: the red points correspond to the sampling of the high frequency curve. As these are too far from each other, the result gives the impression of a low frequency signal.

Figure 2: Aliasing effect on a sine wave

It is then important to choose the correct print interval for a simulation in order to get the right frequency results.