Lowpass Digital Filter Example

A two-pole Butterworth filter is designed using the method illustrated in Example 12.3. The cutoff frequency is 1000 hz and the sampling period is T=1/10000. The resulting filter is shown below. The red circles show the values of |H| at the digital frequencies corresponding the analog frequencies of 400 hz and 4000 hz, which are the components in x(t). (Recall that .)

Click on the time responses to hear the resulting signal.

The m-file that generated these figures can be downloaded from here.