We present a new computer-aided modeling methodology to develop physicsbased models for passive components. We coherently integrate full-wave electromagnetic simulators, artificial neural networks, multivariable rational functions, dimensional analysis, and frequency mapping to establish broadband models. We consider both frequency-independent and frequency-dependent empirical models. Frequency mapping is used to develop the frequency-dependent empirical models. Useful properties of the frequency mapping are presented and utilized in the modeling process. We also consider the transformation from frequency-dependent models into frequency-independent ones in addition to the passivity of the frequency-dependent empirical model. We illustrate the modeling process through various examples, including a microstrip right angle bend, a microstrip via, a microstrip double-step (to be used as a basic element of constructing a model for nonuniform or tapered microstrip transmission lines), and a coplanar waveguide step junction.ITESO, A.C.McMaster UniversityBandler Corporation