DESIGN OF COMPLEMENTARY RECURSIVE DIGITAL FILTERS BASED ON GROUP DELAY APPROXIMATION
Goran Stančić, Saša V. Nikolić, Dragan D. Mančić, Igor D. Jovanovic · SCIndeks · 2015
This paper describes a new procedure for design of complementary IIR digital filters based on group delay approximation. The filters are realized as parallel sum of two all-pass filters, a structure for which low complexity implementations exist. The problem with phase warping which is inevitable if filter design is made through phase approximation will be solved using a proposed method. Adequate initial solution is also proposed. Realized amplitude characteristics of complementary filters will be approximately equiripple. The design examples illustrate that the proposed algorithm is very efficient in terms of computation time and number of iterations.