Title :
Generalised maximally flat approximation
Author :
Barros, M.de P. ; Lind, L.F.
Author_Institution :
University of Essex, Department of Electronic Systems Engineering, Colchester, UK
fDate :
10/1/1987 12:00:00 AM
Abstract :
An analytical method to generalise the classical Butterworth approximation into a maximally flat approximation function possessing finite and asymmetric transmission zeros is presented. The passband of this general function is no longer restricted to the usual ¿ 3 dB at ±1 rad/s coordinates, and therefore extremely asymmetric characteristics can be generated, such as those required by pseudohighpass or pseudolowpass filters. The final network realisation can be conveniently absorbed into narrowband crystal filter design techniques. Two examples are given.
Keywords :
approximation theory; crystal resonators; high-pass filters; linear network synthesis; low-pass filters; lumped parameter networks; passive filters; asymmetric characteristics; classical Butterworth approximation; design techniques; lumped passive filters; maximally flat approximation function; narrowband crystal filter;
Journal_Title :
Electronic Circuits and Systems, IEE Proceedings G
DOI :
10.1049/ip-g-1:19870033
