Dual printed meander monopole antennas for passive UHF RFID tags

This paper presents two new compact designs of dual printed meander monopole antennas for passive UHF RFID tags that operate with multi-port RFID chips. The designed antennas have a smaller footprint in comparison with the commonly used dual dipole-type antennas thus reducing the area needed for the RFID tag. For maximum power transfer to the chips and conjugate impedance matching, the antennas are inductively-coupled with printed loops. A compact tag prototype is fabricated with the area of only 51 mm × 43 mm using a Rogers RO4350B substrate with the thickness of 1.524 mm. Experimental results demonstrate achieving a maximum readable range of 8.65 m.