A Compact Passive UHF RFID Meandered Dipole Tag

This paper investigates a compact design of a meandered dipole passive ultra high frequency (UHF) radio frequency identification (RFID) tag for the Pakistani frequency band (865- 868 MHz). To reduce the tag size, meandering technique and inductive complex impedance structure was incorporated in the proposed design. The overall dimensions of the tag is 0.108 lambda(0) x 0.063 lambda(0) where lambda(0) is the free space wavelength at 867 MHz. The tag was fabricated on Rogers FR4 substrate with the relative permittivity of 4.6 and thickness of 1.6 mm. The measured result of the return loss of the proposed tag agrees well with the simulated result. The proposed passive UHF RFID tag has a computed read range of 3.96 for 0.1 W ERP (Effective Radiated Power) which fulfills the criteria of passive UHF RFID read range, i. e., greater than 3 meters and less than 10 meters in a direction normal to the reader.