Compact chipless RFID metamaterial based structure using textile material

A novel multi-resonator using rectangular slotted complementary split ring resonator (CSRR) on planar transmission line is proposed for the design of chipless RFID tag. The chipless design consists of 4 rings resonator which etched on the back of the substrate and is connected to 50 ohm planar transmission line. Each resonator enables to code in four different allocations (00, 01, 10, 11) with bandwidth allocation of 200 MHz. The 8 bits chipless tag with low insertion loss (below -13 dB) operates from 2.5 to 6.5 GHz. The 25 mm × 20 mm flexible chip-less RFID tag is designed on the fleece substrate (ε_r=1.35, thickness= 1mm, tan δ=0.025). At the end, the effects of orientation of split ring resonator, number of elements and substrate types are studied and analyzed.