volume | PIER Journals

Abstract

In this study, a miniaturized long-read-range anti-metal ultra-high frequency (UHF) RFID tag patch antenna for bank cash transport boxes is presented. Short-circuit inductors were loaded on the side of the antenna, and double H-shaped slots were etched on the patch surface. These structures extend the current path and increase the electrical length, which lowers the resonant frequency and enables antenna miniaturization. The antenna impedance can be flexibly tuned by adjusting the position and width of the short-circuit inductors and the length of the double H-shaped slots. Conjugate matching with the RFID chip is therefore achieved to ensure maximum power transfer. In addition, the short-circuit inductors reduce the influence of the metal plate and improve the current distribution. Consequently, the radiation efficiency is enhanced, and a long reading distance is obtained. The proposed antenna was fabricated and measured, and good agreement between the simulation and measurement results was observed. The measured results show that the antenna occupied an area of 615 mm² and achieved a maximum reading distance of 12.4 m when mounted on a metal cash-in-transit box. The presented antenna is suitable for the full-process management of bank cash transport boxes in different application scenarios.

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Dr. Bingqing Yao