Chipless near field resistive element sensor using phase processing

Abstract

A magnetically coupled near-field chipless resistive sensor label, based on measuring phase at a single frequency is presented. The sensor need not determine the exact resonant frequency or quality factor, and offers high sensitivity, accuracy and dynamic range. It is also insensitive to read range variation and orientation. Being a magnetically coupled near-field system, it is fundamentally more robust against clutter compared to propagating wave counterparts. An equivalent circuit analysis in conjunction with circuit simulation and experiments is presented.

A Review of Chipless Remote Sensing Solutions Based on RFID Technology

“…The antennas used in this approach are usually loop antennas (for inductive coupling) and although many of the well-known examples of chipped RFID systems use near-field technologies, chipless near-field technologies have also been implemented. Examples of this include the work of Paredes et al [22], that of Lee et al [23], the sensor presented by Mukherjee in Reference [24] along with the design depicted in Reference [25] by Herrojo et al The approaches used in these tags are basically the same as their far-field counterparts but with limited read ranges, and although this review concentrates on far-field chipless RFID systems, the same principles apply to near-field tag design. However, although the read range at the commonly used 13.56 MHz is several metres, the resonators to operate at this frequency are quite large.…”

Three-Dimensional Chipless RFID Tags: Fabrication through Additive Manufacturing

“…Although it is possible to cope with the backscattering noise adopting various strategies [ 33 , 34 , 35 , 36 ], for some applications, it is not required to achieve read ranges greater than a few centimeters, and therefore, near-field reading schemes have been employed even for chipless RFIDs. This can be the case when sensitive information is transferred or for increased data capacity or monitoring purposes [ 37 , 38 ].…”