Field-to-Long-Segmented-Trace Coupling With Arbitrary Loads and a Transparent Upper Bound Using a Single Modified Taylor Cell

Abstract

In modern electronic products, the printed circuit board (PCB) traces may well form the dominant coupling path in radiated immunity problems. Therefore, an understanding of the designable parameters that influence the worst-case induced voltages can be of use to the PCB designer, together with rapid simulations. Therefore, a modified single (unmeshed) Taylor cell is combined with transmission line theory to predict the terminal voltages induced by a grazing, vertically polarized plane wave, incident on a multi-segment trace with arbitrary terminal impedances. The resulting model is closed-form and therefore suitable for rapid simulations. Furthermore, the model is geometrically approximated to provide understanding on how designable PCB parameters determine the worst-case induced voltage. Finally, the model is compared to measurement results.

Dominant Coupling Mechanism for Integrated Circuit Immunity of SOIC Packages Up To 10 GHz

“…The coupling of an incident plane wave to a PCB at the left of Figure 1b will be modeled with the Single Modified Taylor cell [5]. To allow for comparison with measurement on a GTEM cell, a simple model for the GTEM's imperfections will be added [6].…”

“…For the case of a vertically polarized, grazing plane wave incident on a microstrip trace with characteristic loads, it has been shown that a single cell may suffice, modified by a correction factor for long line effects [8]. Basic transmission line theory can then by applied to take into account arbitrary loads [5].…”

Taking Into Account GTEM Field Nonuniformities in Radiated Immunity Simulations Through a Simple Measurement

“…For the simulation, a modified Taylor cell was used, which predicts the coupling of a vertically polarized, grazing incident plane wave to a multi-segment trace of constant characteristic impedance, with arbitrary terminal loads [2].…”

“…Therefore, additional proof was needed that the problem lie in the GTEM cell, and not in the model. A full-wave simulation was run, which closely resembled the simulation of the model [2]. Yet, still more proof was needed.…”