A Flexible and Compact Metamaterial UHF RID Tag for Remote Sensing in Human Health

This paper presents a miniaturized UHF RFID tag antenna with increased gain using meander line techniques and metamaterial (MTM). The designed tag operates in the UHF RFID frequency band ranging from 860 to 960 MHz. It comprises of meandered lines with two hexagonal split ring resonators (H-SRRs) MTM cells. It is designed on a photo paper as its substrate which is 0.27 mm thick, with a dielectric constant of 3.2 and loss tangent of 0.05. Next, an RFID tag (NXP SL381213 UCODE G2iL chip) with an impedance of 23-j224 $\Omega$ is integrated with the proposed antenna to assess its performance in terms of reflection coefficient, antenna gain and maximum reading range. The overall size of the tag is 92 mm x26 mm.