Analysis of a sampled data system for the optimal digitizing of analog filters

The paper develops the analytical foundation for two IIR filter design methods that have been previously conceived as numerical algorithms for the approximation of analog filters: the extended window digitizing (EWD) method and the matched-pole (MP) frequency sampling design. The derivation of the EWD equations is based on a sampled data system representation, and provides a rigorous foundation for the MP method. Also, an original analysis of a previously proposed optimization process is done by using the equations developed for the sampled data system.