Moving average filter cut-off frequency

How do we define the cut-off frequency for a simple moving-average filter. And since the transfer function of a typical moving average filter is given by doesω respresent the cut-off frequency?

Answer 1

[Jesús Zambrano]

Hi Mir Khadim,

The cutoff frequency is defined as the frequency where the power gain is a half, also called as the −3 dB-point, because

In the particular case of the moving average filter, just solve the following equation:

,

where is the cut-off frequency. This should give you the following expression:

,

which is an equation that has no analytical solution, then numericla methods should be used to find . Solutions at are not valid cause the transfer function is not defined. Then, the solutions should be found in the region .

Hope thhis can help to solve your question.