Digital Implementation of Fractional-Order Step Filters

This paper outlines the digital implementation of analog fractional step filters. The discrete approximation of fractional order operator sα is first obtained using signal modeling technique based on new mapping function (NMF). Then, the obtained approximation is substituting in the transfer function of the analog fractional order filter to obtain discrete rational transfer function. Simulation results show that the frequency responses of the digital filters are close to those of analog filters for large band of frequencies.