A Mechanically Reconfigurable Chipless RFID Tag for Internet of Things (IoT) Applications

The growing demand for versatile and cost-effective systems for Internet of Things (IoT) applications has paved the way for reconfigurable systems where a single structure can be reconfigured to respond as per the requirements. In the present work, a mechanically reconfigurable chipless RFID tag is presented. The proposed backscatter based RFID tag is built on FR4 substrate with dielectric constant (er) 4.4 and loss tangent (tan δ) 0.02. The substrate consists of four cavities that can be left empty or filled with some material leading to 16 different combinations. Each combination gives a unique RCS signature that can, in turn, be used for safe and reliable data encoding. One of the biggest limitations of RFID tags is that they are expensive when compared to the traditional barcodes. However, the proposed, being reconfigurable, is easy to fabricate and can be manufactured in bulk, thereby, reducing the overall cost of production. It is also reported that the proposed mechanically frequency reconfigurable RFID tag can give out a large number of (theoretically infinite) RCS signatures if the cavities are filled with materials other than that of the substrate material, thereby, further increasing the diversity of the prototype.