A new ring microstrip diplexer

An original structure, a method and results of computer-aided synthesis of a new ring microstrip diplexer are considered. These diplexers for matched loads give ideal decoupling between sources and practically pure resistive inputs over the whole frequency band. A scattering matrix for any order filters and results of scattering parameter analysis of ring diplexer when operating into an unmatched load are presented. The frequency characteristics obtained are compared with parameters of a ring hybrid on transmission lines.