Rectenna harvests electricity from radio waves

Now here is a novel idea – you know those unseen radio waves that are all around us? Well, what if someone were to find a way to harvest said radio waves? This is what Nihon Dengyo Kosaku did, rolling out the rectenna – a combination of the abbreviated words ‘rectifying’ and ‘antenna’, where it will go about its task of converting radio waves into electricity.

The rectenna is rather thin at just 12mm for Wi-Fi signals and 30mm for digital terrestrial broadcast waves, relying on a mere 50µW of power to start. That makes sense, considering it would be a waste if it used up more electricity during the conversion process compared to the amount of electricity harvested.

Wireless LANs are said to enable the rectenna to generate power in micro-watts at a distance of around 10cm, and this development might just spur hardware manufacturers to churn out computers that operate on power in the micro-watt range, powering sensors or tag devices in the process.

Edwin Kee
Categories: Gadgets, Green