Screening attenuation of differential cable-connector assemblies

High speed data transmission is now required in many applications. One limiting factor on speed can be radiated emissions. This paper presents simulation and measurement results on electromagnetic leakage of various differential cable connector assemblies. Leakage modelling aspects are also considered. Differential and common mode interferences as well as single and double shielded assemblies where grounding pin number directly connected to the cable screen varies are studied. The research methods are FIT simulations and absorbing clamp measurements. It is shown that the symmetry of the differential shielding is important and to suppress common mode interferences high amount of grounding pins is required when unscreened connectors like typical high-speed digital ones are used. Double shielded assemblies leak much less.