ASSEMBLY FOR FEEDING IN HF CURRENT FOR TUBULAR CATHODES

An arrangement is provided for feeding in HF current for rotatable tubular cathodes in a vacuum chamber of a plasma coating system as well as a high frequency current source. Located inside the tubular cathode is a magnet arrangement that extends along said tubular cathode for generating a magnetic field. The arrangement enables a low loss infeed of HF current, so that a particularly homogeneous sputter removal from the tubular cathode is guaranteed. The HF current source is coupled to the tubular cathode inside the vacuum chamber by a capacitive infeed of HF current in the form of a coupling capacitor. The coupling capacitor includes a part of the surface of the tubular cathode and a metal plate or metal film that surrounds the tubular cathode, at least partially, at a specified distance.