Design of a compact RF energy harvester for wireless sensor networks

We present a method for powering electronic devices from ambient Radio Frequency (RF) signals. Our proposed design of RF energy harvester is made of a compact ferrite rod antenna together with the electronics necessary for converting the received signal into a form that can directly replace batteries. We show that our device can, in principal, power a wireless sensor node from ambient medium wave transmissions so long as the node is within 120 km of a 150kW transmitter.