Rectennas

Updated November 25, 2011

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The word "rectenna" is a form of portmanteau. In this case it is a cross between an antenna and a rectifier. A rectenna is not a common site, although some forms of RFID tags might be considered to be rectennas.

A rectenna is used at the receiving end of wireless energy transfer. Wireless power transmission (WPT) is the terminology most often used to describe this endeavor.

History of rectennas

Nicola Tesla was the inventor of the rectenna idea, and for that any many other reasons he appears in the Microwave Hall of Fame. His vision was that RF energy fields could be made provide energy to tap into anywhere, just put up an antenna and power up whatever you like. Tesla was absolutely a genius, but there is a lot of junk science out there that has made him into comic-book superhero status. Wireless energy transfer using induction was one of his craziest ideas. In 1898 he convinced J. P. Morgan to fund an installation on Long Island which was to provide wireless communication as well as wireless energy across the Atlantic. It was never finished, and Morgan stopped funding because he didn't like the idea of "free" energy. The 187 foot tower was removed by the U.S. government in 1917 because it was thought to serve as a landmark for German submarines.

Wardenclyff tower

William Cyrus Brown

Bill Brown is regarded as the father of wireless power transmission technology. Check out this tribute to him! He also appears in our Microwave Hall of Fame. Brown used a single-polarization Gaussian beam focused on the device that power was transferred to, a much more practical approach compared to Tesla.

These images came from Bill's daughter Barbara. We'll build some content around them in short order, be sure to check back soon!

Richard Dickinson talks about his friend and colleague Bill Brown