Synthesis of Distributed Elliptic-Function Filters from Lumped-Constant Prototypes

A synthesis procedure for distributed elliptic-function filters utilizing published tables of lumped-constant elliptic-function filters has been devised. It is dependent upon the application of a new generalized transformation for distributed networks. The filters often require the realization of distributed Brune sections, and several novel practical realizations are given both for general and degenerate Brune (i.e., Foster) sections. Examples are given of elliptic function stop band and pass band filters having both wide and narrow bandwidths, and experimental results show good agreement with theory.