in horizontal orientations. The wavelength of 13.56 MHz systems corresponds to about 22 m.
However, the antenna size is a small fraction of that in size and the operating distance is in
the range of the reader antenna's diameter. Hence, the interaction between the reader and
the ring happens in the near field of the interrogator. This leads to the fact, that the
fundamental working principle can be described by a transformer, the capacitive or inductive …