Effects of skew on EMI for HDMI connectors and cables

This paper describes the effects of intra-pair skew on electromagnetic interference (EMI) for High Definition Multimedia Interface (HDMI) connectors and cables by analyzing both simulations and measurement results. Measurement methods like VLSI GTEM and current clamps are used to show the effects of skew on EMI for terminated HDMI connector/cable assemblies. Numerical simulations are used to study several factors contributing to skew in a differential cable and their impacts on EMI. Both the measurement and simulation data show a clear trend of increased EMI that corresponds to an increase in skew. The data indicates the need for a lower cable skew specification for high speed connectors and cables to better facilitate compliance with FCC regulations.