Characterization of microstrip meanders in PCB interconnects

Meandering traces are often used to increase delay times in printed circuit board (PCB) interconnects. An accurate analysis of meanders in today's high speed digital circuits needs to take into account a number of different effects, including near field coupling between the turns of the meander and reflections at the line discontinuities. These effects have a significant impact on the delay and waveshape of the propagated signal. In this paper we analyze microstrip meander structures using a finite difference time domain (FDTD) based full wave method and a quasi-static technique. Signal propagation through meanders with different trace separations is examined. Shortcomings of the quasi-static approach are pointed out. Simple design guidelines are given.