Non-Foster Active Transmission Line with Nearly Dispersionless ENZ Behavior

An RF transmission line with nearly dispersionless superluminal phase velocity (an ENZ behavior) is investigated numerically and experimentally. The structure employs periodic loading of a standard transmission line with active NIC-based negative capacitors or negative inductors. It is shown possible to achieve a stable operation within a band wider than one octave. Such a line might find applications in broadband negative delay circuits and in wideband electromagnetic cloaks.