Characterization and modeling of a new via structure in multilayered printed circuit boards

We demonstrate that structure engineering of the transmission line near the via can reduce the amount of reflection of the RF signal. We have fabricated two types of vias with different transmission line geometries and have measured the reflection. The measured results show that the shape of the transmission line near the via hole is important in determining the total reflection of the via structure. The amount of reflection obtained from full three-dimensional (3-D) electromagnetic simulations can reproduce the measured results with reasonable accuracy, which suggests that efficient design of the via structure could be possible without resorting to hardware fabrication and characterization.