Transmission line matrix modeling of disperse wide-band absorbing boundaries with time-domain diakoptics for S-parameter extraction

A numerical modeling procedure based on Johns time-domain diakoptics approach with space interpolation techniques for efficient transmission-line matrix (TLM) analysis of two-dimensional microwave circuits is discussed. Frequency-dispersive boundaries are represented in the time domain by their characteristic impulse response or numerical Green´s function (Johns matrix). Almost perfect wide-band absorbing boundary conditions have been obtained with this technique, permitting accurate characterization of waveguide discontinuities and compounds. The application of these techniques saves considerable computer run time and memory when compared with conventional TLM analysis