RF Energy Harvesting from GFSK-Modulated BLE Signals

This work presents a study on the feasibility of energy harvesting from modulated signals that are present normally in daily life environments, i.e. Bluetooth Low Energy. First, the design of the RF-to-DC conversion circuit is presented, considering the input excitation being a signal modulated in frequency. Next, a measurement campaign has been conducted considering as input signal both a frequency-modulated excitation given by a signal generator, and the communication packets sent by means of a commercial Bluetooth board. The experimental results show that it is possible to harvest about 1.3 nJ for every BLE packet sent with a transmitter-receiver distance up to 20 cm with 4 dBm of transmitted power.