Variable magnitude characteristics of 1-D IIR discrete filters by a generalized bilinear transformation

It is shown that variable magnitude characteristics can be obtained by the application of a general bilinear transformation of the type s/spl rarr/a/sub 1/z+a/sub 0//b/sub 1/z+b/sub 0/ to a known analog filter. Stability considerations dictate the limits of the values of a/sub 1/, a/sub 0/, b/sub 1/ and b/sub 0/; and these limits have been determined. Starting from some known filter characteristics in the analog domain, it is shown that different magnitude characteristics can be obtained in the discrete domain.