Design method of analog low-pass filters with monotonic characteristics and arbitrary flatness

In analog filters with monotonic amplitude characteristics, there exists a significant difference in the flatness between Butterworth filters and L fi lters. However, there are no reports on low-pass analog filters with charac teristics that are intermediate of those two, that is, in which the amplitu de is monotonic and the flatness is arbitrary In this paper, by means of Ja cobi polynomials, a mathematically closed transfer function of such a filte r is proposed. The proposed transfer function incorporates those of Butterw orth filters and L filters. Also, this transfer function can be realized at arbitrary order for both even and odd orders. (C) 1999 Scripta Technica.