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

Abstract

Abstract: A 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.