Electronically Re-Writable Chipless RFID Tag Using Solid State Metal-Insulator-Metal Switches on Paper Substrate

In this article, we present the design and results of an electronically re-writable chipless RFID tag on paper substrate. This tag consists of two resonators build around a modified shorted dipole, integrated with a non-volatile Metal-Insulator-Metal (MIM) switch, which tunes the electrical length of each resonator to resonate at two different frequencies, depending on state of the switch. One can electronically reconfigure the tag using low power DC pulses to change its RF signature. The integrated MIM switch has a layer architecture of Silver-Nafion-Aluminum, formed exclusively using an in-house process in ambient laboratory conditions, notably without the use of any `clean room' facilities. Operating mechanism of the tag is validated with the help of developed electrical equivalent model. This study proves the concept of realizing `electronically reconfigurable' chipless tags on flexible and low cost substrates, with a fabrication process compatible with mass production.