Combined RFID tag antenna for recipients containing liquids

Abstract

In UHF RFID (radio frequency identification), passive tag antennas can be fixed on boxes or recipients where the nature and contents might vary. These variations strongly affect the antenna performance. A combined antenna is proposed to ensure an effective read‐range for a plastic recipient containing water or not. Two separate antennas are first designed for the filled and unfilled cases, respectively, then combined for a correct working in both configurations.