A study on the model of the slit on the ground plane

On a printed circuit board, if a slit on the ground plane exists between two lines, then the coupling between the lines is increased in some cases. This paper proposes the model that allows easy evaluation of the transmission characteristics of the lines (include coupling between lines) if a slit exists. This model is composed of a transmission line, where the slit acts as a slot line, an ideal transformer coupling, where magnetic field coupling is assumed between the slit and the line, and a line through which signals are transmitted. The values of calculating the transmission characteristics using this model show good agreement with measured values.