Bandwidth enlargement of inductively-coupled UHF RFID tag antennas based on a dual-dipole topology

In UHF RFID (Radio Frequency Identification), passive tag antennas are usually fixed on textiles, boxes or recipients which nature and contents might vary. These variations strongly affect the antenna performance. A combined antenna showing wideband characteristics is proposed to ensure an effective read-range for moderate variations of the dielectric permittivity and thickness of the tagged items. A prototype realized on Kapton is measured and tested on a plastic support.