A two-step perturbation technique for nonuniform single and differential lines

A novel two-step perturbation technique to analyze nonuniform single and differential transmission lines in the frequency domain is presented. Here, nonuniformities are considered as perturbations with respect to a nominal uniform line, allowing an interconnect designer to easily see what the effect of (unwanted) perturbations might be. Based on the Telegrapher's equations, the proposed approach yields second-order ordinary distributed differential equations with source terms. Solving these equations in conjunction with the pertinent boundary conditions leads to the sought-for currents and voltages along the lines. The accuracy and efficiency of the perturbation technique is demonstrated for a linearly tapered microstrip line and for a pair of coupled lines with random nonuniformities. Moreover, the necessity of adopting a two-step perturbation in order to get a good accuracy is also illustrated

A perturbation technique to analyze the influence of fiber weave effects on differential signaling

We study differential signaling via a pair of striplines in a substrate that is comprised of an epoxy/fiberglass woven composite structure. The transmission characteristics, which are deteriorated due to the presence of the fiber weave, are analyzed via an efficient modeling technique for nonuniform transmission lines. This technique is based on the solution of the pertinent differential equations using a perturbation approach. For a challenging application example, it is shown that the unavoidable phase errors can be controlled by subdividing electrically long lines into smaller pieces, as such increasing accuracy whilst maintaining efficiency

Novel modeling strategy for a BCI set-up applied in an automotive application: an industrial way to use EM simulation tools to help Hardware and ASIC designers to improve their designs for immunity tests

Electronics suppliers of automotive industry use BCI (Bulk Current Injection) measurements to qualify immunity robustness of their equipment whereas electronics components manufacturers use DPI (Direct Power Injection) to qualify immunity of their component. Due to harness resonances, levels obtained during a BCI test exceed standard DPI requirements imposed by automotive suppliers onto components' manufacturers. We propose to use BCI set-up modeling to calculate the equivalent DPI level obtained at the component level during equipment testing and to compare results with DPI measurements realized at IC level