Modeling experiences with full-wave time-domain modeling software

Abstract

When evaluating electromagnetic modeling software, there is usually a significant focus on the ldquoaccuracyrdquo of the software. Differences between the results generated by the software and the ldquocorrectrdquo solution are the result of several potential sources of error including: approximations made in order to represent the actual configuration as a structure that the software can understand; approximations made during the discretization and solution of Maxwellpsilas equations; and differences between what the modeler wants to analyze and what the software is actually modeling. Of these three potential error sources, the last one is usually the greatest source of error even when the analysis is being done by experienced modelers. In this paper, three full-wave time-domain EM modeling codes are evaluated by analyzing three simple canonical problems. These codes employ the three most common time-domain modeling techniques: the transmission line matrix method (TLM), the finite integration technique (FIT) and the finite difference time domain technique (FDTD). The three canonical problems are a center-driven dipole, a circuit board power-bus structure, and a power-bus structure with a cable attached. All of the codes are capable of yielding accurate results, but the differences in the specific technique employed and the user interface have a significant effect on the simulation time and the likelihood of getting the correct answer.