Energy Harvesting from Ambient Radio Frequency: Is it Worth it?

Ambient energy harvesting has been an attractive area of research due to its prospective applications in several modern low-power systems. The paper reports on the feasibility assessment of energy harvesting from ambient radio frequency signals radiated by different communication sources. The rectenna efficiency and leakage current of a storage capacitor are identified as major sources limiting the harvested power and hence considered as core elements in the development of a practical ambient RF energy harvester. A couple of experiments were performed to analyze the spectrogram of ambient RF energy and the effect of capacitor leakage as well as the level of harvested energy that may be needed by low consumption applications.