Computing the Effect of Fringing Fields on Capacitance

Application ID: 12605

A typical capacitor is composed of two conductive objects with a dielectric in between them. A voltage difference applied between these objects results in an electric field between them. This electric field exists not just directly between the conductive objects, but extends some distance away, this is known as a fringing field. To accurately predict the capacitance of a capacitor, the domain used to model the fringing field must be sufficiently large, and the appropriate boundary conditions must be used. Here, a parallel plate capacitor in air is modeled, and the size of the air domain is studied. The choice of boundary condition is also addressed.

This model example illustrates applications of this type that would nominally be built using the following products: