An arrangement and a corresponding method for influencing and/or detecting magnetic particles in a region of action include storing required reactive energy in a tank circuit, which is preferably operating at the center frequency of a magnetic particle imaging (MPI) drive field. Reactive elements, such as capacitors and/or inductors, couple one or more tank circuits to the drive field resonator. The coupling strength maybe varied by switching additional reactive elements into and out of the coupling unit to vary the strength of coupling.