Cascaded Triplet filter design using Cascade synthesis approach

A unified review of design of Cascaded Triplet (CT) filters is presented. Cascade synthesis approach with pole placement is used to synthesize the filter and then Norton transformations are used to put the circuit into a standard form for conversion into CT form. Sections of the filter containing FTZs are then converted into Bridge Tees forming the CT sections. An example is given showing development of equivalent alternative CT filter structures having all-inductive, all capacitive or mixed cross-couplings, depending on the location of FTZs with respect to passband