Investigation of the Mechanisms Behind EMI Issues Caused by Ready-Made Connecting Devices in Electronic Systems

Ready-Made Connecting Devices (RMCD) are being commonly used in different environments. However, it has been reported that RMCD connectors can lead to EMI issues. Several studies have been conducted to investigate the relationship between RMCD connector parameters and the EMI-related influence on electronic systems. However, a detailed explanation of the relevant mechanisms of such influence is still lacking. Based on measured scattering parameters (S-parameters) of RMCD connectors with different parameters (i.e., different number and distribution of shielding wires) and circuit simulations, this paper shows that the parameters of imperfectly shielded RMCD connectors introduce different degrees of impedance discontinuity. Consequently, different voltage drops over the connectors in the cabling of a system are generated, which further leads to different levels of EMI issues.