Capacitance of an Open Circuit Via Port

The port capacitance as part of a power plane structure is defined and calculated using a series expansion for the electrostatic field Then by choosing a suitable surface surrounding the via, Gauss´s Law is applied to obtain a numerically stable expression for the capacitance, written in series form. Attention is paid to the influence of dimensions and material on the capacitance value, and comparisons with Method-of-Moment based simulation packages are made.