Synthesis of monotonic passband sharp cutoff filters with constant group delay response

A new technique is developed for determining nonminimumphase filter functions that can meet stringent specifications for both the attenuation and group delay characteristics. The organization of a computer program for automatic computation of these transfer functions according to any prescribed specifications is described. As revealed by comparison with some other known approximation techniques, the method proposed is very effective, especially when the delay equalization to within a prescribed error is not required over the entire passband.