Signal integrity

Welcome to the Signal Integrity Column! In this issue, several practical measurement techniques for multiport via-array measurements are compared and discussed. Via structures are commonly used in multilayer printed circuit boards, and they play a significant role in the signal and power integrity designs for high-speed signals. In the connector or IC footprint where multiple vias are often closely placed in an array, the geometry results in non-ideal effects such as mismatch, loss, crosstalk, mode conversion, and so on. Accurately characterizing the electrical performance of the vias helps the designers quantify the non-ideal factors inevitably in the design and provides useful insights for geometry and material optimization. Further, measurements can provide validations for simulation models. The summary and conclusions provided in this article are also insightful for other high-frequency measurements and the applications of various calibration/de-embedding techniques.