TABLE OF CONTENTS Instead of multielement lumped models, we can use the simple equivalent circuit of Figure 8.2(c). The complex frequency dependency of C, ESR, and ESL can, in general, be taken into account by turning the three elements frequency dependent [13]. This will prevent us from using the models in some time-domain simulators, but the model fits well to frequency-domain simulators and spreadsheetlike solutions. This approach follows the widely used standard solution to describe the complex propagation of high-speed interconnects, traces, and transmission lines with frequency-dependent R-L-C parameters.
In black-box modeling we do not necessarily need to understand the physical cause of the behavior to be modeled. However, we do need to know how the signatures vary over the range of parameters to be modeled so that we can find an effective way to describe them. With a small set of measured data, we could find fairly accurate curve fitted functions under any arbitrary circumstances. However, small datasets may lead to different approximation functions for different cases, while knowledge of the general trends would enable us to find common functions. If we can find simple building blocks so that each block is just a weak function of frequency, the actual response can be constructed as the linear superposition or product of the building blocks.
In frequency-domain characterization of electronic circuits many response functions have a simpler expression if plotted on logarithmic frequency scale. In Chapter 4, we saw that the dielectric constant and loss...
