Optimized First-order s-to-z Mapping Function for IIR Filter Designing

The Bilinear transform is widely used in IIR filter designing for the mapping of s and z planes. This transforms gives a stable first-order s-to-z mapping function. However, it suffers from frequency warping which deteriorates the digitally transformed system. In this work, an attempt has been made to develop an efficient first-order s-to-z mapping using PSO (particle swarm optimization) algorithm. The proposed s-to-z mapping function gives better linear mapping from s-to-z plane than the existing Bilinear transform. Therefore, proposed mapping function is less prone to frequency warping effect in IIR filter designing. Several mathematical simulations have been done to see the authenticity and merits of the proposed s-to-z mapping function.