Novel antenna design with four concentric spirals, each having 2.5 turns. Rf power is connected to the centre and ground is at the outer connectors
Gans, Timo & Crintea, Dragos & O'Connell, Deborah & Czarnetzki, Uwe. (2007). A planar inductively coupled radio-frequency magnetic neutral loop discharge. Journal of Physics D: Applied Physics. 40. 4508. 10.1088/0022-3727/40/15/021.












