Novel Butterfly Slot Based Chipless RFID Tag

A compact chipless RFID tag with robust readable features is presented in this paper. The tag is made up of novel concentric butterfly slot resonators. Bit data is encoded in the frequency signature of the tag. Each slot corresponds to a resonance peak representing a bit '1', whereas an absence of the peak signifies a bit '0'. Proposed resonator design demonstrates insensitivity to different polarization and incident angles of the linearly polarized impinging electromagnetic wave. The tag operates in the frequency band of 4.7-9.7 GHz, limited within the license free ultra wide-band. Rogers RT/duroid (R) 5880 substrate is used to realize a 10-bit capacity design that spans 14 x 14 mm(2) resulting in a bit density of 5.1 bits/cm(2)