Two fast convergent algorithms for the design of equiripple IIR and FIR filters in the log magnitude sense

This paper proposes two algorithms for the design of equiripple filters in the log magnitude sense. The first one is a Remez-type algorithm, and is based on an accelerated Lawson algorithm. It is used to design log IIR filters. The fast convergence of this algorithm compared to the classic Lawson based algorithm is illustrated by design examples. The second algorithm is used for linear phase log FIR filter design. It is based on the Remez algorithm with an iteratively refined weighting function. Design examples showing its robustness and fast convergence are presented.