Planar Near-Field RFID Reader Antenna for Item-Level Tagging

In this letter, we propose a novel UHF planar near-field antenna for the application of RFID item-level tagging. The proposed antenna was designed to have a strong and uniform H-z-field over a broad antenna aperture to identify the various items with stable reading performance. To obtain a strong near H-z-field, two coupled patches are employed along with a microstrip-line feed, resulting in average H-z of -15 dBA/m on antenna aperture (30 x 30 x 10 cm(3)). We also measured the reading range, and it confirmed that the proposed antenna is suitable for a commercial RFID smart-shelf application.