Synthesis of low-sensitivity second-order digital filters using genetic programming with automatically defined functions

This letter proposes a synthesis method for low coefficient sensitivity sec ond-order IIR digital filter structures using Genetic Programming with Auto matically Defined Functions (GP-ADF). In this letter, digital filter struct ures are represented as S-expressions with subroutines, It is easy to gener ate syntactically valid S-expressions and perform the genetic operations, b ecause the representation is suitable for GP. A numerical example uses the fitness measure, including the magnitude sensitivity, and demonstrates that the proposed method can synthesize efficiently very low coefficient sensit ivity filter structures.