In past years, chipless RFID technique has attracted significant attention due to the
low manufacturing cost expectation. By eliminating the use of silicon IC chips,
chipless RFID tags can offer more competitive price than normal silicon IC based tags.
Besides, chipless tags possess longer communication range since they do not
necessitate the use of transistors as silicon based tags that require a threshold voltage
to power up IC circuits [6]. The chipless tags that have been successfully
commercialized are surface acoustic wave (SAW) tags [29, 30]. The attractive
advantages for these SAW tags involve the compatibility with present RFID band
regulations (2.45 GHz) and allowing for large coding capacity (96-bit). The cost of
such a tag, however, is close to that of the silicon based counterparts since they