Efficient ambient WiFi energy harvesting technology and its applications

This paper is focused on powering wireless devices (including sensors) with high efficiency circuitry that can harvest ambient WiFi/Bluetooth energy and convert into direct current (dc). Herewith, we introduce a novel circuitry to generate a battery-like voltage from very low incoming RF energy (<;-20 dBm). The new RF energy harvesting front-end is demonstrated to have much better conversion efficiency than state-of-the-art commercial RF harvesting modules, notably for low power levels. Realization of this rectification circuitry is a game-changing technology in powering mobile devices. To verify our energy harvesting design, we carry out an experiment where our RF harvesting module provides enough power to drive a commercial temperature/humidity meter with an LCD display using nothing more than ambient WiFi signals in a typical office environment.