Identify the source, return path and coupling mechanism
- Common-mode / differential-mode
Common-mode currents share a direction relative to a reference and return elsewhere. Differential-mode current flows out and back on the pair.
- Electromagnetic couplingThis term
Electric and magnetic fields can transfer disturbance between circuits. Shared conductive impedance provides another coupling path.
- Crosstalk
A signal on one channel couples into another. Cable geometry, separation, screening and terminations affect the resulting coupling.
- Inductance / capacitance
Inductance stores energy in a magnetic field, while capacitance stores energy in an electric field. Both matter in cable and circuit behaviour.
- Radio-frequency interference (RFI)
Radio-frequency disturbances can reach a circuit through radiated or conducted paths. Assess the relevant frequency and installed geometry.
Disturbance can couple through electric fields, magnetic fields or shared conductive paths. Common-mode current and differential-mode current follow different return routes.
Conceptual conductor arrangements. Arrows illustrate current directions rather than actual magnitudes; no universal shielding or filtering solution is implied.