S. Kapora

Reduction of inductive common-mode coupling of printed circuit boards by nearby U-shaped metal cabinet panel

The effect of a nearby U-shaped metal cabinet panel on the inductive common-mode coupling of a printed circuit board (PCB) is calculated in a two-dimensional (2-D) model by Schwarz-Christoffel (SC) transformations for doubly connected regions. Such an open metal cabinet can significantly reduce the mutual inductance between the microstrip lines on the PCB and the common-mode circuit if the cabinet is properly connected. But it may also increase the coupling for balanced pairs of tracks, in particular where the coupling for a single track varies strongly with position. Details of the SC approach are presented. The SC results agree with those of a static method of moments approach, but also clearly indicate the accuracy limits of the latter method.

Shielded Tracks on a Printed Circuit Board

Fully shielded tracks can be embedded in multilayer printed circuit boards by a novel manufacturing technique. The paper presents a numerical analysis of the influence of dimension tolerances on the characteristic impedance. For partly shielded tracks the coupling between tracks and the environment is studied as well. The analysis relies on a two-dimensional approach, using Conformal Transformations and a static Method of Moments.