Non-foster Matching for High-Power Electrically Small Antennas
Foster's reactance theorem dictates that all passive impedance propagate clockwise around the Smith chart (i.e.,|dX/dw|>=0). The ideal impedance matching network would then be a component which propagates counter-clockwide around the Smith chart. Such an impedance is called a non-Foster's impedance and includes negative capacitors and negative inductors. These impedances are necessary non-passive and therefore must be constructed of active devices and are therefore limited in their ability to hand high power levels. We are working on simple high-power single negative impedances which can withstand approximately one watt as well as collections of distributed non-Foster circuits which can collectively withstand tens to hundreds of watts.