My first thought was "phased array". When I found his patent, sure enough, that is what he is doing. http://www.google.com/patents/US8159364 David, AJ4TF K2 7006 -- View this message in context: http://elecraft.365791.n2.nabble.com/Re-OT-Wireless-chargers-tp7578867p7578873.html Sent from the Elecraft mailing list archive at Nabble.com.