EMC Cables with protection against electromagnetic interence
Almost everyone nowadays talks about EMC (Electro Magnetic Compatibility) related problems and the European regulatory issues concerning EMC. Very few, however, succeed in offering realistic and easily applicable solutions. Thanks to many decades of experience with cable manufacturing, combined with a thorough knowledge in the field of EMC, KABELWERK EUPEN can offer you a clear solution for some of your EMC problems. The protection our cables give against signal disturbance from outside or against disturbance of the environment by the signal itself, is based upon a technique of coating conductors or cable screens with an absorptive layer of ferrite composite.
Explanation of extruded ferrite technology
Ferrite technology the basis of this technology is a high quality ferrite powder. KABELWERK EUPEN developed a special compound: a polymer material mixed with a considerable quantity of homogeneously fine ferrite powder. This compound is called EMC/COM and it can be extruded around copper conductors.
The ferrite itself is a non-conducting material, but it has a very interesting magnetic behaviour. As a ferromagnetic material, it will go through hysteresis loops whenever it is under influence of an alternating magnetic field. Consecutively magnetizing and demagnetizing the material will cause considerable losses of high frequency energy. This energy is absorbed in the ferrite grains and converted into heat.This effect is more or less proportional to the field frequency.
By coating conductors with a thin layer of ferrite compound, high frequencies will be strongly attenuated, because their energy will be absorbed by the ferrite powder.This applies to high frequency disturbances that are propagating on the conductor and which we don't want to disturb the environment, as well as to surrounding interferences, which we want to prevent from disturbing the signals on our cable.
The efficiency of a cable screen against electromagnetic disturbances is based upon two distinct effects. The electric field component is mainly reflected, whereas the magnetic component will be attenuated through eddy current losses in the cable screen. By applying a layer of ferrite-filled elastomeres (EMC/COM) onto the screen of a screened cable, it is possible to obtain a considerable attenuation of the currents that circulate on the outer side of the screen. The effect is comparable to the application of ferrite beads along the cable, but the homogeneous coating of Kabelwerk Eupen's CMS cables does not cause any steep changes in the impedance, thus avoiding reflections.CMS cables are very useful in any circumstances where common mode disturbances or surface currents are creating problems.