Coupling and decoupling are the methods of injecting, and removing, a waveform or signal onto the intend line or cable to verify the impact that it has onto the equipment under test (EUT). There is a variety of different methods for achieving this depending upon the required testing criteria or standard. This is commonly required for conducted immunity testing and there are a variety of different testing requirements for the associated equipment facilitating it. The challenge with this type of equipment is finding the network that best fits both the standard and type of line that the testing is anticipated to be done on.
There are many standards that require the ability to inject pulses/signals onto associated cables or lines. It is important to note that standards often place different requirements on the methodology and equipment used to achieve this.
EN/ IEC 61000-4 Series
EN IEC 61000-4-4 - Burst / Electronic Fast Transient (EFT)