A compact time-domain 16PSK chipless RFID tag design for IoT sensing application

Abstract

Radio Frequency Identification, or RFID, is a kind of electronic identification technology that has been widely used in daily life. By receiving radio frequency signal and reflect back with certain phase or frequency without manual intervention, RFID tag can identify itself and reflect data stored in the tag. Conventional RFID tags with silicon chip are facing the problem of difficulty and high cost in production when comparing with other identification technology, such as QR codes and barcodes. The chip inside the tag is an important reason to limit RFID production cost, production difficulty and operation environment. So, in order to reduce production cost and difficulty, chipless RFID technology is being studied in depth.\\ In this thesis, a passive 16 Phase Shift Key (16PSK) modulated chipless RFID tag operating at 2.4Ghz is introduced. Based on 16PSK modulation realized by adjustable stub line connected with Wilkinson power divider, the chipless RFID tag can obtain 4-bit information. The information stored in the tag can be changed easily after fabrication by changing the length of a stub line through bonding or conductive gluing. The CRLH based time delay component is compact and useful in providing a long delay at 2.4Ghz, which is long enough for modulation component to create response signal. A monopole antenna resonating at 2.4Ghz is included in the tag. A 1.54mm thick Rogers RO4003C is used as the substrate of the tag. The result of measurement and simulation are discussed in the thesis.