The study of crosstalk in high-speed circuit design

In high-speed circuit design, crosstalk between traces is a very serious problem. They can couple unwanted signals to each other. When there is no slot, the return path is just under the trace and the current is in opposite direction. The interference current is small because the cancel effect of the image current. But when there is slot on the reference plane, the return current have to find another path around the slots and this effect will create obvious potential for crosstalk between the signal returns and in some circumstances the crosstalk could be very strong. In this paper, we study crosstalk with FDTD method especially for the slotted ground case. The result of this paper is very useful to the high-speed circuit design. We can use these results in the practical high-speed circuit design.