Power distribution network design and characterization using virtual ground fence

In mixed-signal systems, noise coupling between different domains, such as digital and RF, can be a critical problem. Especially the power/ground planes in packages or boards can be a major factor for noise coupling. Simultaneously switching drivers cause supply voltage fluctuations which can propagate both horizontally and vertically between the power/ground planes. The sensitive RF/analog signals have to be isolated from this digital switching noise, which gets coupled through the shared power distribution system. Hence, accurate estimation and improvement of the performance of power/ground planes is critical in a mixed-signal system. For this purpose we propose a new design methodology, called the virtual ground fence. In this paper, we present measurement characterization of power and ground planes including the virtual ground fence.