EMC screening of cables and lines

Ferrite rings for filtering of interference frequency

We provide you with cable assemblies with ferrite rings for filtering of interference frequencies on coaxial cables (sheath current filter). Increase the reliability: stop high-frequency interference reliable and provide safe operation of your machines and plants.

Why ferrite rings on coaxial cables?
Many electrical and electronic devices produce high-frequency interferences.
These interferences are often led out of the device by connected coaxial cables and can lead to problems with the compliance to EMC-directives. The whole cable, or rather its screen, acts like an antenna.

For damping the so-called common-mode interference, sheath current filters are used.

They consist of ferrite rings, which are layed around the cable. For later attachment, there are divided snap-in ferrites (so-called split ferrites).

Ferrite rings are components made of magnetic ferrite. If such a ferrite is layed around a coaxial cable, a higher inductance develops at this place. Together with the already existing capacity of the cables, a ferrite represents a low-pass filter. It filters out high-frequency interferences of the transmitted signal.

The effect of the low-pass depends on the number of windings around the ferrite and the capacity of the cable. Thinner coaxial cables for example can be winded around the ferrite several times to get a higher attenuation of the interference frequency. It should be noted, that the cable must not be damped too much to not threaten the transmission of the signal! A compromise has to be found to lower the interference and transmit the wanted signal lossless.


The removal of the ferrites does not worsen the transmission of the signal, but can lead to problems with the compliance of the EMC-directives.

The KOAX24 team would like to advise you on the use of ferrites on coaxial cables for suppression of common-mode interference.
On request we assemble your coaxial cable with suitable ferrites.
We provide a vibration resistant installation by glueing or shrinking the ferrites.