銳截止單調響應曲線之低通網路設計

Abstract

Effects of introducing multiple pairs of coincident jω-axis zeros in the class L filter functions are investigated. It is shown that for the same order n, modified filters with finite zeros provide sharper cutoff rate than the conventional all pole filters.Expressions for cutoff slope and minimum attenuation in the stopband are derived in terms of the order n, the number of zeros m and their locations.A design example is given to illustrate the procedures for finding out the proper transfer functions.