A two-sided rational approximation method for recursive digital filtering

A two-sided rational approximation procedure for recursive digital filter design is presented in this paper. More specifically, an explicit expression for the designed filter transfer function can be obtained once a rational approximation for the analytic part of the Fourier series expansion of the desired filter characteristic is determined. To demonstrate the efficiency of this technique, we derive a two-sided Padé approximation method. Several examples are given to illustrate this design procedure.