Design of CT and CQ filters using approximation and optimization

A new design technique for CT filters has been derived commencing from the well-known Chebyshev all-pole prototype filter. One or more finite frequency poles may be introduced by cross coupling across sets of three nodes, and the filter re-matched by approximate compensation of the element values. Any general optimizer may then be used to obtain a nearly perfect result without undue concern over convergence failures. The method may be combined with a similar previous theory for CQ sections.