Can I use FDATool to design IIR low/ high pass filters specifying the Q value and the cutoff frequency?

I would like to design an IIR low / high pass filter modifying Q, cutoff, and peak frequency using FDATool.

Answer 1

[MathWorks Support Team]

The ability to design IIR low/high pass filters by specifying the Q, cutoff frequency, and peak frequency is not available in FDATool. However, it is possible to create a peaking filter specifying Q and the peaking frequency using FDATool.

Here is a description of how to create a single-peak IIR filter in FDATool, using Q to specify the Q-factor and specifying the peak frequency.

1) Open FDATool.

2) In Response Types, select Peaking from the Differentiator list.

3) In Design Method, select IIR.

4) After Selecting IIR, choose Single Peak from the IIR list.

5) In the Frequency Specifications, select the Q option and specify the Q-factor to use. The default value is 0.45.

6) Set the other filter specifications as you require, setting the peaking frequency with the Fpeak option.

7) Click Design Filter to generate the peaking IIR filter in FDATool.

You can also create peaking filters with a comb structure by selecting Comb rather than Single Peak from the IIR list. In this case you cannot specify the peaking frequency.