RECURSIVE COEFFICIENT COMPUTATION FOR DERIVING FILTERS FROM LOWPASS PROTOTYPES USING RATIONAL TRANSFORMATIONS

A recursive algorithm is presented for calculating the coefficients of a filter derived from a lowpass prototype transfer function when a ra tional transformation is applied to the parameter. The method is gener al, valid for prototypes having both poles and zeros, and provides exc ellent accuracy. It is applicable in the continuous or discrete domain and also for designing digital filters from analogue filters.