Circuit Based Near-Field Localization: Calibration Algorithms and Experimental Results

For a network consisting of inductively coupled nodes, we experimentally demonstrate circuit-based localization of a passive and chipless agent device. By using measurements of the input reflection at multiple anchor nodes, we reconstruct the unknown position of an agent node in a coplanar arrangement for both random and optimized anchor arrangements. A key step for applying this localization scheme in a practical setup is the introduction of a calibration phase which, in contrast to previous work, eliminates the need for explicit knowledge of the involved circuits. Furthermore, we improve localization performance by investigating imperfections in the measurement device and applying appropriate compensation methods. In the employed setup, we demonstrate a median localization RMSE of 1.1 mm, making the proposed scheme a promising method for precise localization in clouds of RFID-like wireless devices.