“Equi-Ripple” Synthesis of Multiband Prototype Filters Using a Remez-Like Algorithm

This letter illustrates a new procedure for evaluating the characteristic polynomials associated to the prototype of a multiband microwave filter. This procedure is based on the Remez algorithm and allows an equiripple response in the assigned filter passbands and stopbands, once the number of poles in each passband and the number of imaginary transmission zeros in each stopband are assigned. Some examples and comparisons are reported to show the effectiveness of the new algorithm which has proved to be significantly faster than a similar one recently published in the literature.