Symmetry degradation of differential circuits induced by uneven gold plating of high-speed connectors in extreme environment

摘要

High-speed connectors are widely used in digital differential circuits. Because of the uneven gold plating, the thin gold plating area on the contact surface of the connector will form corrosion films in extreme environment, which may not only deteriorate the reflection and transmission performance of electromagnetic wave in differential circuits but also affects its symmetry, which results in poor communication quality. In this work, considering the influence of differential circuit symmetry on the signal transmission, reflection and crosstalk, the d parameter was defined for measuring the circuit symmetry. The impact of high-speed connector degradation on symmetry of differential circuits was studied by both experimental investigation and electromagnetic numerical calculation model analysis. These results are helpful in developing a better understanding of impact of connector degradation on symmetry of high-speed differential circuits and in identifying failure features in fault diagnosis.