A hybrid method for efficiently estimating common-mode radiation from transmission-line structures

This paper describes a computationally efficient means of predicting the radiated emissions from transmission-line structures with high aspect ratios. Common-mode currents are generally the principal source of radiated emissions from these structures but cannot be calculated by conventional circuit analysis techniques. Present full-wave numerical analysis methods consume too much computation time on such structures to find wide use among hardware designers. The hybrid method integrates multiconductor transmission line (MTL) elements into partial-element equivalent circuit (PEEC) models. It was applied to a variety of asymmetric structures and was found to estimate the worst-case radiated emissions across a broad frequency range with generally good correspondence to a full-wave solution. The computation speed advantage of this method grows dramatically as the aspect ratio of the structure increases.