Example (continued)

• If we measure the Frequency response of this filter at all frequencies between f=0 and f=0.5, we find the responses shown below.
• The filter is essentially a lowpass filter, i.e., low frequencies pass easily while higher frequencies are attenuated.
• The magnitude response has a zero at f=0.1, hence a sinusoid at that frequency is rejected.

  

Figure 4.10: Frequency Response of Digital Filter