Abstract: A coil assembly for generating or for receiving alternating magnetic fields comprises at least one primary coil having at least one winding and comprises at least one secondary coil provided for a selective influencing of the resonance behavior of the coil assembly and having at least one winding, wherein the primary coil has a main conductor and a shielding conductor at least sectionally surrounding the main conductor. The shielding conductor is electrically conductively connected to the main conductor and has at least one section that is electrically interrupted.