Both sensor and platform are equipped with antennas or respectively coils. In analogy to similar radio frequency identification, RFID, techniques, the power link between both is modeled as loosely coupled transformer whereas the platform represents the primary and the sensor which corresponds to the secondary winding of the transformer [6], [7]. The platform (Fig. 5) is equipped with a single turn loop antenna, which is glued on a heavy plastic board with a ferrite plate bellow. More precisely, the layout enclose an area of 20x28cm and have a track width of 1cm. Due to the geometry, the corresponding amplitude of the field shows a significant reduction in approximately 20cm distance to the antenna plane.