A formal approach toward developing an equivalent circuit for high-speed coupled interconnects with intermediate ground insertion

Ground tracks are normally inserted between high-speed signal interconnects to make them immune to crosstalk. It is seen that the intermediate ground tracks (insertions) effectively reduce crosstalk and signal overshoots and ringing, and it is a common design practice to ensure better signal integrity. The paper aims at developing a formal approach toward determining the equivalent capacitance and inductance parameters for coupled interconnect lines with intermediate ground insertion. A unified approach is used to extract the self and mutual capacitances and inductances - thereby developing the equivalent circuit for such an interconnect structure. The results are compared with an accurate field simulator to check the veracity of our proposed model and are found to be in excellent agreement. The proposed method would enable fast and accurate computation of circuit parameters for similar interconnect structures, thus making it suitable for use in CAD-oriented design tools.