“…Typically, each resonant element provides a bit of information, and the encoding is determined by the absence or presence of singularities in the amplitude and/or phase of the frequency response of the tag. According to the type of interaction between the interrogation signal and the tag, frequency domain-based tags can be classified as retransmission-based [54,55,56,57,58,59,60,61,62,63,64] and backscattered-based [65,66,67,68,69,70,71,72,73,74,75,76,77,78,79] tags.…”