A complete modal analysis is introduced to derive the crosstalk voltage waveform in multiconductor coupled systems. In addition to the capacitance and inductance matrices, it also includes a resistance matrix. The offdiagonal terms of the resistance matrix are related to the return path, which is important for accurate noise modeling at high frequency. It is shown that the error in crosstalk peak noise can be as high as 30% if the return path resistance is ignored. This work completes a previous modal analysis of a multiconductor system and significantly improves accuracy of crosstalk noise estimation, which is becoming increasingly important in design of deep-submicron integrated circuits.