A compact printable dual-polarized chipless RFID tag using slot length variation in ´I´ slot resonators

A compact printable dual-polarized (DP) chipless RFID tag using slot length variation encoding technique in `I´ shaped slot resonators is presented in this paper with simulation and measurement results for barcode replacement. First, the `I´ shaped slot resonators are etched from a square metallic patch in both vertical (V) and horizontal (H) directions, which double the encoding capacity within a fixed frequency band by using the polarization sensitivity property of the `I´ slot resonators. Next, the slot length variation encoding technique is added to reduce the number of `I´ slots required for encoding data, which in turn reduces the tag size, and allows more gap between successive slots that reduces the mutual coupling and improves the printing tolerance. After that, a 16-bit proof of concept DP tag is designed, simulated, fabricated and measured that achieved 4.1 bit/cm2 data density, which is higher than many reported works to date. Therefore, the proposed single sided easily printable tag possesses a good prospect due to its higher encoding capacity and data density, and can replace barcode in item level tagging of low cost and printable items, where tags will be required in trillions.