A Simple Picosecond Pulse Generator Based on a Pair of Step Recovery   Diodes
  A picosecond pulse generator based on a pair of step recovery diodes (SRD), leveraging the transient response of the SRD PN junction and controlling the pulse width by a resistor, is proposed. We first explain the operation principle of the device, decomposing the pulse generation into different phases, and then demonstrate an experimental prototype with two different resistance, and hence pulse width, values. 
Lianfeng Zou, Shulabh Gupta, Christophe Caloz
physics.ins-det