40 GHz PCB Interconnect Validation: Expectations vs Reality

摘要

Frequency content of digital signals in PCB interconnects have increased up to 40-50 GHz in recent years. To ensure that interconnects work as expected over this bandwidth, we have to build validation boards. This paper reports lessons learned from a validation project with the goal to build a formal procedure for systematic prediction of the interconnect behavior up to 40 GHz. We will go through selection of test structures, connectors and measurement equipment, demonstrate uncertainties of the analysis based on the initial pre-manufacturing assumptions and how close to reality we get with more formal approach based on material models and manufacturer adjustments identification.