Interference Coupling Mechanisms

Interference Coupling Mechanisms

Overview To put the proper EMC measures to use during planning and in service, you need to know types, effects and methods of transfer of the coupled interference. This is the only way to effectively combat the problems. Generally, the physical laws of energy transfer in electromagnetic fields apply for the coupling.

Methods of transfer The interference can be transferred along a conductive wire (guided) or through space (unguided/radiated). Interferences are normally found together as line guided and radiated interference and are coupled to inputs, outputs, the power supply and data lines.

"Size" Wave lengths If the wave lengths of the interference variables are greater that the characteristic measurements of the source and receiver, the transfer mechanisms for electrical and magnetic fields are monitored separately.  Galvanic coupling with common impedances on the influential electrical circuits (source and receiver)  Inductive coupling with the common magnetic field of source and receiver (low pass field coupling)  Capacitive coupling with the electrical field between the source and receiver (low pass field coupling)

"Small" Wave lengths If the wave lengths of the interference are the same or are less than the characteristic measurements of the source and receiver, a coupling over the electromagnetic field must be monitored. The following influential mechanisms play a part:  Wave influence with wave activity on lines  Radiated coupling through space

Coupling mechanisms Interference coupling occurs via the following mechanisms: