Autonomous and Battery-Free Wireless Tag combining UWB and BLE Technology

Abstract

This paper presents a multifunctional, battery-free tag combining Bluetooth Low Energy (BLE) and Ultra-Wideband (UWB) technology powered by the far-field wireless power transmission technique. The proposed tag, with a size of 9 x 8 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , can be used for asset tracking via UWB at a center frequency of 4 GHz or for wireless temperature and humidity monitoring via BLE at 2.45 GHz. The tag is powered by a highly efficient radiofrequency (RF) energy harvesting (EH) solution at 868 MHz. The proposed solution has been optimised for low power consumption of 5-15 μJ (for a single UWB transmission) and can provide reliable performance in terms of data sensing and geolocation at a low ambient power density. The electronic module that includes the features of the energy harvester (rectifier) and the UWB transceiver was previously developed by Uwinloc. Simulation results for both antennas (UWB and RF EH) were presented. The transmission rate in BLE and UWB configuration was also evaluated as a function of the EIRP power level.