Recycling Radio Waves
Researchers led by Manos Tentzeris have developed an electromagnetic energy harvester that can collect enough ambient energy from the radio frequency (RF) spectrum to operate devices for the Internet of Things (IoT), smart skin and smart city sensors, and wearable electronics. Harvesting radio waves is not brand new, but previous efforts have been limited to short-range systems located within meters of the energy source, explained Tentzeris, a professor in Georgia Tech’s School of Electrical and Computer Engineering. His team is the first to demonstrate long-range energy harvesting as far as seven miles from a source. The researchers unveiled their technology in 2012, harvesting tens of microwatts from a single UHF television channel. Since then, they’ve dramatically increased capabilities to collect energy from multiple TV channels, Wi-Fi, cellular, and handheld electronic devices, enabling the system to harvest power in the order of milliwatts. Hallmarks of the technology inclu...