Developing printable chipless RFID tags seems a very attractive topic given the
fact that printing techniques are high throughput processes. Additionally, printing
technologies like inkjet printing are fully additive processes – solely depositing
material on the demanded positions of substrates, offering a potential pathway to save
a large amount of expensive electronic materials in fabrication. Also, printing
techniques are compatible with cheap flexible substrates including plastic and paper
sheets, holding high possibility to further drive down the tag costs . As a
matter of fact, a number of research results on printable chipless RFID tags have been
reported in recent years . One of the most promising families is the
chipless tags developed on the application of electromagnetic properties of printable
metallic structures. According to the adopted encoding principles, these chipless tags
can be basically classified into two categories:
• Time domain signature based RFID tags
• Frequency domain footprint based RFID tags