Characterization of Microstrip

CharacterizaTIon of Microstrip Meanders in PCB Interconnects Meandering traces are often used to increase delay TImes inprinted circuit board (PCB) interconnects. An accurateanalysis of meanders in today’s high speed digital circuitsneeds to take into account a number of different effects,including near field coupling between the turns of the meanderand reflecTIons at the line disconTInuities. These effects have asignificant impact on the delay and waveshape of thepropagated signal. In this paper we analyze microstripmeander structures using a finite difference time domain(FDTD) based full wave method and a quasi-static technique.Signal propagation through meanders with different traceseparations is examined. Shortcomings of the quasi-staticapproach are pointed out. Simple design guidelines are given.IntroductionIn many analog and digital applications, printed circuit board(PCB) interconnect delays need to be tightly controlled ormatched. This is typically done through the use of delayrouting. A number of structures that implement controlledsignal delays have been developed and analyzed through theyears (e.g., [1-3]). The meander line is one of these structures(Fig. 1). It is an array of coupled parallel commensurateconductors. The meander line is a special case in the generalset of planar structures that consist of coupled parallelconductors between ground planes or on top of a ground plane.