An optimum linear phase approximation with small delay obtained by the manipulation of all-pass Padé approximants

Abstract

This paper proposes a new rational approximation of a symmetric impulse response. The proposed technique uses both the Pade method to obtain an all-pass approximation of e−sT and specific zeros in order to achieve good phase linearity characteristics. The obtained functions, when compared with other classical ones, such as Bessel, for instance, present better linear phase characteristics with a smaller delay. Another advantage of this approach is that the transfer functions are provided in explicit forms. Finally, the effect of varying parameters and results from simulations are shown.