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.
William Cyrus Brown
Bill Brown is regarded as the
father of wireless power transmission technology. Check out this
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!
talks about his friend and colleague Bill Brown