TDR/TDT analysis by crosstalk in single and differential meander delay lines for high speed PCB applications

Meander (serpentine) delay lines are generally used for controlling the skew of the traces in high-speed Printed Circuit Board (PCB) applications. They consist of equal-length unit lines closely packed to each other. However the meander lines deteriorate the total time delay and the waveform distortion in the end of the lines, since each unit line is tightly coupled. In this paper, to predict accurate Time-Domain Reflectometry/Time-Domain Transmit (TDR/TDT) waveforms by crosstalk in the single and differential meander line, simple TDR/TDT equations are proposed in point of the signal integrity. The proposed TDR/TDT waveform equations are verified by using TDR/TDT measurements in the single and differential meander delay lines.