Direct synthesis of folded symmetric resonator filters with source-load coupling

A direct synthesis technique of coupled symmetric resonator filters with source-load coupling is presented. An examination of the implications of power conservation on the possible solutions to the synthesis problem is examined. It is shown that at least two different coupling matrices whose entries differ not only in signs but in magnitude, as well, can be extracted. The two matrices have the same coupling and routing scheme. Typical examples of synthesized filters are presented to document the validity of the technique.