Ultrafast Coplanar Air-Transmission Lines
We demonstrate subpicosecond electrical pulse propagation using coplanar air-transmission lines. Risetimes of 0.8 ps after 2.8 mm of propagation are achieved with a velocity of propagation which is 86% of the speed of light in vacuum. Our results suggest that intrachip communication in digital circuits with risetimes as short as one picosecond is readily achievable using electrical signals.