Design of variable phase filter with minimax criterion and iterative method

Abstract

This paper investigates the design of a variable phase digital filter with a minimax criterion. The problem becomes a non-convex optimization problem with respect to the filter coefficients. An iterative optimization procedure is developed for solving the optimization problem. Design examples show that the proposed methods can obtain the optimal solution with a small number of iterations. In addition, the proposed methods can obtain a significant improvement in the maximum frequency response error and the maximum phase error deviation over other existing methods.