Electric-field-coupled contactless ID sensor for cm-level high-precision positioning item-level tagging systems

Abstract

To detect multiple identifications (IDs) for cm-level high-precision positioning item-level tagging (ILT) systems in near-field ultra-high-frequency RFID applications, an electric-field-coupled multiple ID sensor is presented. The proposed ID sensor consists of four circular electric coupling parts, an impedance-matching network, and an SP4T switch for position control. By switching the electric-field-coupled sensing parts, cm-level position detection of densely aggregated RFID tags for a small-sized ILT can be achieved. The sensing distance of the proposed ID sensor is approximate to 7 mm and its physical size is 50 x 50 mm(2) (approximate to 1/7(0) at 920 MHz).