Abstract
The affect of the ground step discontinuity created by a difference in package and printed circuit board (PCB) thickness was studied. It is observed that the step in the reference conductor can be represented by a series inductance and its value depends on the height of the step and the width of the transmission line above it. The overall circuit affects for a packaged transistors were simulated with commercially available electromagnetic 2D and 3D CAD tools. The results show that the discontinuity creates an inductive feedback path around the package.