Self dual l.t.a. filters

In this paper self-dual linear transformation active (l.t.a.) filter structures are introduced. The general linear transformation approach is constrained to this end to produce the necessary and sufficient conditions for self duality from which active-RC realisations of given lossless ladder filters are effected. Further degrees of freedom within the self-dual concept are then effectively utilised to produce active-RC realisations of highly modular form. These concepts are developed in this paper and are also applied to the design of two filters, the performance of which is most satisfactory.