Editor’s note: I came across this excellent tutorial article on Digital Filter Design and I thought it would be an excellent guide for novices as well as seasoned veterans. I want to thank William H.

The design of finite impulse response (FIR) filters remains a cornerstone of digital signal processing, with ongoing efforts to refine both the algorithmic and hardware aspects of their implementation ...

As a parting shot, I pointed out that there are three quadratic terms there with unity coefficients of z 0 – and there are three deep nulls in the filter’s gain response, as was shown in the figures ...