Re: Mapping coefficient of continues transfer function to di
ali_th,
Tigana123 raises some good points regarding the impulse invariant method to implement the elliptic filter. These comments also apply to the Chebyshev type 2 (Inverse Chebyshev) filter, or, for that matter, any filter that has real zeros in the stopband. Antoniou describes a modified impulse invariant method that overcomes the probelems of direct application of the impulse invariant transformation to these filters. For more information, see the following:
Ntoniou, Abdreas, "Digital Filters Analysis, Design and Applications.
Regards,
Kral
Added after 2 minutes:
Sorry; I had "finger blight" when typing the author's name. It is Antoniou, Andreas.
Added after 2 minutes:
Another point to keep in mind; because of the aliasing problem, the impulse invariant method can only be used for low-pass and band-pass filters. It does not work for high-pass or band-reject filters.