FDTD analysis on the current and electric field distribution in aPCB stripline structure

摘要

An FDTD analysis is reported on changes in distributions of thestripline current, image current and electric field in a PCB striplinestructure of stripline-dielectric-ground plane as the dielectricthickness and stripline width are varied and these distributions aredescribed graphically. As the ratio of the stripline width w to thedielectric thickness h, w/h, went to greater than 1, the striplinecurrent was distributed on the bottom side of the stripline, the imagecurrent was concentrated just under its corresponding stripline, andmost of the emitted field produced by the stripline was confined withinthe dielectric. As the ratio went to less than 1, the stripline currentstarted being distributed on all the outer surface of the stripline, theimage current was more spread in its width, and more emitted field cameout of the dielectric. Variation of w/h from 0.1 to 2 caused only alittle change in the stripline current and electric field intensityinside the dielectric, but the field is much reduced outside both inintensity and spatially, which means that decrease in the dielectricthickness could raise the PCB circuit density