Design and SAR Analysis of a Meander Slot Antenna for Backscattering RFID Applications

The technology known as RFID, or “Radio Frequency Identification”, uses RF signals to enable wireless identification and tracking. This paper presents the design of a meander slot monopole antenna for backscattering RFID (radio frequency identification) applications. The substrate material used is PET (polyethylene terephthalate) with a thickness of 0.110 mm, and silver is used for patch material with a thickness of 0.065 mm. The dielectric constant and the tangent loss of the PET are 2.1 and 0.0002, respectively. The proposed antenna’s dimensions are 43×72.5×0.175 mm3. The complementary structures of the meander line are incorporated into the design to enhance bandwidth and achieve a lower |S11| value of −55 dB at 2.45 GHz. The designed antenna has a resonating frequency of 2.45 GHz and a bandwidth of 1 GHz, i.e., from 1.95 GHz to 2.95 GHz. The gain of the designed antenna is 6.25 dBi. The SAR analysis generated a SAR value of 0.90 W/kg, which is within the safe limit of 2W/kg averaged over 10g of tissue as specified by the ICNIRP (International Commission of Non-Ionization Radiation Protection). The antenna design and simulation are performed using CST (computer simulated technology) studio suite. The antenna design is edge fed using a designed SMA (sub-miniature coaxial connector) model in order to obtain more realistic simulation results. For material selection, the factors such as flexibility and safe wearability on the human body. The proposed antenna covers the unlicensed 2.4 to 2.5 GHz RFID band and is suitable for an efficient RFID backscattering application.