Compact Meandered Folded-Dipole RFID Tag Antenna for Dual Band Operation in UHF Range

A meandered tag antenna is proposed for dual band operation in UHF (Ultra High Frequency) range at f₁ = 866 MHz and f₂ = 912 MHz. Initially, the proposed tag consists of folded dipole configuration with extended meandered arms to achieve single resonating band. The inverted L-shaped stub is embedded at the lower arm of the folded dipole to introduce additional resonance and realize the dual band operation at desired resonant frequencies. The proposed tag’s impedance is optimised to match conjugately to the RFID IC (Alien Higgs-4). The proposed dual-band tag is designed and simulated using CST microwave studio. The tag prototype is fabricated and is experimentally characterised to verify its impedance matching with respect to the employed RFID IC. The read range performance of the fabricated tag prototype is measured experimentally by placing the proposed tag on different type of objects like wood, fibre, plastic etc. validating its environment tolerance capability. The proposed tag is found to perform well in all the presented scenarios. The proposed tag is compact with volumetric size of dimensions 1920 mm³ and exhibits measured read range of 5.5 m and 5.8 m at 866 MHz and 912 MHz.