Abstract: An RFID label comprises a resonant circuit consisting of a coil and a capacitor. The RFID label is provided with an additional element (13, 17, 20, 21) for regulating the resonance frequency of the resonant circuit. The additional element is applied to the surface of the RFID label after production of the same. The additional element can be especially a sticker with a conductive layer, which is stuck in such a way that it partially overlaps individual conductive surfaces of the label to produce an additional capacitance, or which is simply stuck into the coil to reduce the effective inductance of the coil. Alternatively, the element can be formed by a layer with a high relative permittivity which is applied between two conductive surfaces.

Abstract: Method and system for reading out and writing to RFID-transponders with inductive coupling including a read/write unit with a transmission frequency fs1 defined as a basic transmission frequency and a plurality of transponders operated at a resonance frequency fR. The resonance frequency fR is fixedly predetermined, then for operating conditions with a high distance range, the resonance frequency fR equal to the basic transmission frequency fs1 is selected. For operating conditions with a high recognition rate with a plurality of transponders located within a detection field, the basic transmission frequency fs1 is reduced to a fixed alternative value fs2 . This procedure guarantees reliable communication between the transponders and the read/write unit.

Abstract: An electronically detectable resonance label, in particular an RFID label, includes a substrate made of plastic foil and conductive surfaces on the front and rear of the substrate. Some of the conductive surfaces form a capacitor in a mutual area of overlap. The label includes a first capacitor plate on the front of the substrate and a second capacitor plate on the rear of the substrate. The capacitor plates are in the shape of elongated strips of uniform width along their entire length. The capacitor plates only partially overlap, and the area of overlap is arranged at a distance from both ends of at least one capacitor plate. This provides the advantage that during the production process relative displacement of the capacitor plates can take place in two directions.