This is not really wireless these have been out for a while now there is no frequance to worry about you put a special cover on your device then place it on mat and it charges that's it

My notion is that a coiled extension cord makes a nice semi-helical antenna (or at least a scramble-wound coil), and is the right size for its distributed capacitance to make it resonant at around the -- whatever, up to say a 100MHz, not crtical because harmonics are fine too. Then, if one touches the metal part, YOU become the path to ground for possibly several hundred volts of RF, probably not fatal, but decidedly dangerous. Extension cord was the best such antenna I came up with off top of my head, however, *any* piece of metal is *possibly* a good enough antenna to produce an unpleasant shock when in proximity to a hundred or so watt transmitter.

Also, a resonant circuit such as a coiled extension cord (this time plugged in) nearby may cause the transmitter to explode because resonates its output tank TOO well. I'm telling you, RF is *funny*, and transmission lines / resonant circuits are unpredictable. (There's a funny story about Steinmetz, famous early engineer for GE, who got stiffed on a new installation in a South American country, so he redesigned a small part of the electric grid -- 60Hz as in sixty -- to form a quarter wave stub, effectively shorting out a multi-megawatt generator. Took them many months to figure out his trick.) -- Have fun learning about RF in your living room, lightning rod.

By the way, to forestall objections: yes, I know these will have various measures to ensure a suitable receiver (therefore absorbing most of the RF) is in proximity. Still going to be leakage and / or common items that fool the transmitter into switching on.

To several different comments.

Yes it is somewhat inefficient, but is coming a long way. I saw a unit that was mounted in the center light ficture in a room and could power everything in the room (2 Cell Phones, a Laptop, a TV, a clock and a DVD Player) all without wires and with a 85% efficiency rating. I would take the 15% hit to have freedom.

Telsa in 1899 at Colorado Springs, transmitted 100 million volts of high-frequency electric power wirelessly over a distance of 26 miles at which he lit up a bank of 200 light bulbs and ran one electric motor, without killing anyone.

Anybody who thinks you're going to get a shock from this needs to resit their phyics GCSE. Unless you (that's you - yourself, a human) can oscillate at the same frequency as the transmitting loop, you're not going to get a shock. It's called induction.

I really doubt that the low voltages these things emit will be dangerous to even small house pets. However, wireless chargers are inherently inefficient as bigger_luddite pointed out, so there ain't no green tint to these devices. Doesn't matter as aPple iTards will quickly adopt them hoping the RF interference will somehow improve their Iphlaw 4's abyssmal lack of reception when holding the device normally in either hand.

Of course even his sAtanic hOliness will begin flogging his own magical and revolutionary supremely overpriced iTard version as a mandatory accessory. This will be introduced along with the iPhlaw 4 iCondom, an improved more natural feeling version of the Bumper case but made of thin latex with raised ridges for extra sensation. The iCondom will be available in rainbow colors and is required to keep those sweaty palms off the iPhlaw 4 built in anti-antenna.

Pre-order yours today as colors may be limited. Note that the white version will not be available initially.

SHOUTER DO YOU ALSO WRITE FOR THE LOCAL PAPER DOING HOROSCOPES

TODAY or TOMORROW YOU MAY OR MAY NOT HAVE A DESIRE TO REPLY TO THIS COMMENT...

Watch out for black cats and ladders... Your lucky numbers are 1 and 69 with your colours of black and white

*sigh*

WIRELESS CHARGING IS GOING TO BE GREAT, UNTIL THE FIRST ELECTROCUTIONS AND-OR FIRES THAT IS. WHO WILL DIE FIRST? I PREDICT A CAT, MAYBE A SLOBBERY DOG, AND SAD TO SAY IT IS ALSO LIKELY TO BE AN INFANT. THE FIRST DEATH INCIDENT WILL LIKELY INVOLVE WATER OR HIGH HUMIDITY. A FAULTY CONTROLLER WILL PROBABLY BE BLAMED, AND IEEE WILL MAKE DESIGN STANDARDS.
I AM GOING TO BE VERY CAUTIOUS ABOUT THIS TECH, BECAUSE I HAVE TOUCHED 110V BEFORE AND IT ISN'T FUNNY.

Don't even have to handle a connector. These are all also inherenty inefficient for transfer of energy. In any case, *I'm* not going to linger near a radio-frequency transmitter, regardless of frequency or power level.

And I foresee discovery that a wide range of common items make fair antennas when a source of RF power is close. Though I don't know the frequencies used, I'll bet that a coiled extension cord is adequate over a broad range to build up a literally shocking voltage. RF is funny, and any resonant circuit can easily get to a potential of hundreds of volts when driven by several watts. Lawyers get ready.