Capacitive coupling

The capacitive coupling is in the electromagnetic compatibility ( EMC) and the circuit technology, the transfer of energy from one circuit to another due to the mutual electrical capacitance represents the capacitive coupling is frequency dependent and decreases with increasing frequency. It relates to the frame of the EMC spatially adjacent different electrical circuit components which are coupled as a result of stray capacitances, - the capacitive coupling circuit also has industrial applications, where the coupling capacity is utilized specifically by suitably selected capacitors.

Similar types of coupling are the inductive coupling, DC coupling and the radiation coupling dar.

Electromagnetic Compatibility

Occurs between two circuits on a potential difference, that is, they are at different potentials, so an electric field E. This electric field can cause changes in temporal displacement currents, which manifest themselves as voltage drops in the useful signal superimposed noise voltage. The field effect is in networks, as shown in the figure on the right, as a capacity with the stray capacitance Cs modeled. A capacitive coupling increases with increasing frequency and may be an intentional or parasitic ( unwanted ) effect.

Capacitive coupling is very strong distance-dependent and therefore can only be used at small distances.

Circuit engineering application

If two parts of a circuit are at different DC potentials, but an alternating voltage signal (for example audio) to be transmitted from one to the other circuit member is on a capacitor therebetween. If it has a sufficiently large capacity, its impedance for AC signals to be transmitted is negligible or at least manageable; the DC voltage component which is needed inter alia for setting the operating point of the amplifier stage is, however, blocked.