An experimental evaluation of surrounding RF energy harvesting devices

In this paper, we present a study of RF energy harvesting devices. The surrounding RF power density was measured. The average of the total radiation power density in broadband (1GHz–3.5GHz) is in the order of −12dBm/m
²
(63µW/m
²
). The maximum of the RF density power is measured in 1.8GHz–1.9GHz frequency band, it is around −14dBm/m
²
. Two rectifiers have been designed and simulated at 1.85GHz and 2.45 GHz. The choice of the load to optimize the recovered DC power is studied, and the various antennas were optimized and evaluated. Multiple rectennas have been designed to recover the ambient RF energy. The best performance is obtained with a spiral antenna.