Time domain analysis of crosstalk with a slot between microstrip lines

The crosstalk between microstrip lines placed closely on a printed circuit board is an important issue. Recently, a lack (a slot) formed in a ground plane may be serious problem for the crosstalk or EMI, because of miniaturization of electronic equipment and printed boards, and high-density of circuits. In this paper, we analyzed the influence of crosstalk between two microstrip lines by placing the slot in the ground plane between them in time domain. And, we showed that the near end crosstalk increases as the slot width increases and the far end crosstalk decreases as the slot length increases. Moreover, it seemed that a signal propagating in the line is coupled with the slot, and another the signal propagating in the slot. Next, we analyzed voltages at near and far end by splitting into odd-mode and even-mode excitation. As a result, we showed that the rise times arrived at the far end in the case that the slot length is different are different each other in odd-mode excitation. And, we showed that the near end voltage depends on the slot width in even-mode excitation.