Application of time domain diakoptics to 3-D TLM method with symmetrical condensed nodes

The diakoptics (segmentation) technique is applied to TLM (transmission-line matrix) analysis of microwave circuits using Johns´s (1987) 3-D symmetrical condensed node. It is shown how a microwave structure can be partitioned into substructures which are solved independently and later reassembled (all in the time domain). Diakoptics leads to considerable reduction in memory and CPU requirements for big structures since it allows numerical preprocessing of those parts of a large electromagnetic structure which remain unchanged during repeated analysis. To check the validity of the proposed approach, the algorithm was applied to compute the scattering parameters of a symmetrical capacitive iris with a gap width equal to 1.659 mm in the WR28 waveguide.<>