Combined RFID tag antenna for recipients containing liquids

RFID systems are characterized by a changing environment which perturbs and degrades the performances of each system component. Passive tag antennas are the most affected by these variations, the tag functionalities vary by changing the surface where it is attached and in some case even the content of boxes or recipients has an influence. A combined antenna is designed in order to ensure a read range for a plastic recipient containing water or not. Before, two particular antennas are proposed to work in each case, both situations are analyzed separately to observe their performances and extract their advantages to join them in one unique structure less sensitive within a limited read range.