According to the invention the coupling unit comprises a ferromagnetic core (30) which encloses a conductor through which a low frequency current (1) is circulating in order to inject thereon a high frequency signal, is characterised in that current (1), circulating through the conductor or the magnetic...http://www.google.de/patents/US20050122092?utm_source=gb-gplus-sharePatent US20050122092 - Process and device for compensating the low frequency magnetic field in an inductive signal coupling unit
