Metamaterial-inspired chipless RFID encoding exploiting phase response

Radio Frequency Identification (RFID) is a widespread tool used in a large spectrum of application spanning from the remote identification of goods, animals tracking and people localization. The vast majority of RFID tags operating in the radiofrequency and microwave bands present today in the market is passive (i.e. without an internal power source) and comprises an antenna tuned to a semiconductor chip that allows the storing of information. Although the cost of this kind of RFID tag is low, it cannot beat the barcode especially for low-price items. Therefore a great effort has recently been put in the development of the so called chipless RFID in order to further reduce the cost of a single tag.