Ambient Backscatter

Posted on August 24, 2013


Radio waves permeate the ether all around us. You can’t see them, and you might not be aware of the vast variety of waves entering your home unannounced. But go buy a scanner or a multi-band radio and tune around for an hour or two and you will soon discover a world of odd sounds and unusual waves that are constantly crashing through your walls.


In recent years, the density or radio waves has only increased with the proliferation of Cellular telephones, wireless network nodes and Wi-Fi hotspots.

Radio waves are a form of energy that can be harnessed and used for purposes other than the one intended by the original generator.

Earlier this month, researchers at the University of Washington, reported on a device they had developed to harness the power in these ambient radio waves. The device was able to use the radio waves as both a source of power for the electronic circuits, and it re-purposed the radio waves and used them as the medium by which the devices could communicate.

“The new communication technique, which the researchers call ‘ambient backscatter,’ takes advantage of the TV and cellular transmissions that already surround us around the clock,” the news release announcing the publication of the research says.

The power generating potential of radio waves is nothing new, Crystal radio sets are able to snatch signals from the air and convert them into enough power to provide the subtle mechanical vibrations in an ear piece needed to produce audio.

The interesting innovation in these circuits is the deliberate re-purposing of the already existing radio waves for communication between the devices, which allows them to operate wireless and without an on-board power supply – no battery required.

The researchers hope their device will find applications in “a number of areas including wearable computing, smart homes and self-sustaining sensor networks.”

Learn more about the research at the University of Washington’s website.

Download the research paper and learn more about how the team of researchers created circuits for “Wireless Communication Out of Thin Air.”

Posted in: Research