Crosstalk noise determination for non-identical lines

VLSI circuits signal integrity is an emerging concern in high performance integrated circuits. We proposed once an analytical expression to calculate the noise amplitude of a two coupled-line RLC interconnects network; this expression being derived from an analytical transmission line model based on the modes propagating through it. However, this expression supposed a perfect symmetry between both the two coupled lines. When system is dissymmetrical, crosstalk amplitude cannot be evaluated in function of the propagation modes anymore. In this paper, a relation permitting to calculate the noise amplitude of such systems is exposed when the dissymmetry results from different lines geometries. It is described depending on a lines width dissymmetrical factor, the amplitude determined when the system is completely symmetrical; results showing an excellent agreement with SPICE simulations.