Filter Families

The location of the poles and zeros of a filter transfer function determines both the magnitude and phase response of that filter. Let us look at several filter families, where each family has a particular scheme for pole and zero placement, resulting in certain unique characteristics. Though there are other filter families, we will focus on these four families: (1) Butterworth Filters, (2) Chebyshev Filters, (3) Elliptic Filters, and (4) Bessel Filters.