Analysis of periodic structures by means of a generalized transverse resonance approach

The characterization of discontinuities in periodic structures with the generalized scattering matrix (GSM) is proposed. These GSMs are obtained by means of a field-matching method and used in combination with the generalized transverse resonance technique (TRT) to analyze periodic waveguides. The partitioning of the structure, the field expansions for TM^z Bloch modes in each partition, and a new GSM cascading procedure are detailed. Three particular structures have been analyzed, two of which have been built and measured, to demonstrate the capabilities of the proposed approach. The measurements confirm the accuracy of this method. More complex cross-sections and even bi-periodic structures can be easily analyzed since the use of the generalized TRT in combination with the GSM concept gives rise to a great versatility.