Design of Highly Distinguishable Letters for Inkjet-Printed Chipless RFID Tags

We consider chipless tags, which are based on Latin letters and also legible, for radio-frequency-identification (RFID) applications. Since letters using standard fonts have relatively weak and smooth responses with respect to frequency, special slits are designed to improve the distinguishability of letters without sacrificing their legibility. The designed set of letters can be used to generate words that are also suitable for RFID applications with their strong and unique scattering characteristics. The tags are fabricated via low-cost inkjet printing, making them both flexible and inexpensive.