The generation of high energy ultra wide band pulses

The authors present a theoretical discussion of the performance of photoconductive switches mounted in a matched transmission line structure. The issues of risetime and power density are addressed. They define a switch performance parameter, alpha , which results in a recipe for optimizing the performance of photoconductive switches. This parameter, which is related to the power produced per unit width of the system and the pulse risetime, shows that, in the high-speed regime, there is no simple trade-off for power and speed, and that high-performance operation necessitates high switch current density, i.e. low impedance and linear operation. The authors also discuss the limits on alpha due to materials' properties and conclude with a discussion of experimental life-testing and a comparison between the theory and experimental results.<>