Compact UHF RFID balun‐like integrated tag antenna for long range detection of water bottles

Abstract

AbstractA compact, flexible, long‐range, and impedance transformer balun‐like integrated UHF RFID tag antenna is proposed for the detection of water bottles. To alleviate the performance of a tag antenna in close proximity to a high dielectric material such as water, the radiating element of the tag antenna uses folded, unbalanced strips made of balun‐like arms wrapped around the tag's body. As a result, a wide bandwidth with reasonably good radiation resistance is achieved. The tag's body comprises dual loops for the impedance matching to the tag chip. This leads to a long read range of 13.33 m; >5.83 m compared to other state‐of‐the‐art designs. The proposed tag antenna conforms to a small footprint by wrapping the balun‐like arms around the tag's body, which results in a compact form. The tag is fabricated, and the results reasonably agree with simulations.