Design and radiation mechanism analysis of a multi‐usage ultra‐high frequency radio frequency identification tag antenna

Abstract

A novel ultra‐high frequency radio frequency identification tag antenna designed for multi‐usage is proposed in this study, which can work on the human body, blood bags, and water‐filled container as well as free space. The tag antenna is fabricated on the F4B‐2 substrate, whose relative permittivity is 2.65 and dielectric loss tangent is 0.002. The radiation unit is formed by four main circular loops, two semicircle loops, and four round arcs, all these loops and arcs are surrounded by an elliptical loop located on the outer edge of the substrate. The antenna has an elliptical structure, whose long axis and short axis are 76, 32 mm, respectively. In different applications, the presented antenna maintains a stable operating frequency and has good conjugate impedance matching with the tag chip.

Circular multi‐usage RFID tag antenna with coding ability for chipless application

“…It can be noted that, due to the existence of the ground in the antenna structure, the gain is much smaller than that of a dipole antenna without a ground. 25 F I G U R E 2 Impedance. A, conjugate impedance matching between the tag antenna and the chip; B, simulation and measurement results…”

“…Figure 4 shows the radiation patterns of the antenna in the free space, which has an omnidirectional characteristic. It can be noted that, due to the existence of the ground in the antenna structure, the gain is much smaller than that of a dipole antenna without a ground 25 …”

“…In previous works, we have discussed in detail the effect of water thickness. 25 The reading range of the tag antenna can be calculated by:…”

“…In other words, the thickness of the water affects the radiation performance of the tag antenna. In previous works, we have discussed in detail the effect of water thickness 25 …”

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

“…For instance, although [23] is only 4 × 7 × 0.1 mm bigger than the proposed counterpart, it offers a 6.68m lowered read range. Furthermore, a multi-slot tag antenna with a 36 × 19 × 0.7 mm bigger size and a 2.28m lower reading range was proposed in [22]. Similarly, [34] offers a lowered 4.78m read range and 75 × 27 × 0.4mm bigger size.…”