Some considerations for using the finite difference time domain technique to analyze microwave integrated circuits

The authors describe the incorporation of the autoregressive method (AR model) and Litva's dispersive boundary condition (DBC) into the finite-difference time-domain method (FD-TD). It is found that the performance of the FD-TD technique is greatly enhanced when used to simulate microwave passive circuits. The results of this study show that for the analysis of typical high-Q circuits, CPU-time savings of up to 90% can be realized by combining AR model and FD-TD. After testing a number of different 50-ohm microstrip lines, the authors conclude that DBC shows good performance and gives excellent results when implemented with FD-TD, if the parameters are chosen properly. The use of this boundary condition can result in a considerable improvement in the accuracy of FD-TD simulations. These results help to demonstrate the usefulness of incorporating both the DBC and AR model with the FD-TD algorithm when analyzing practical microwave circuits.<
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