Drift step recovery diode

The drift step recovery diode, abbreviated DSRD, is a variant of the step recovery diode, a semiconductor junction diode able to generate extremely short pulses for microwave electronics, and was invented by Russian scientists in 1981, credited in the source to Grekhov and colleagues. Like the ordinary step recovery diode it stores charge during forward conduction and then stops its reverse current abruptly once that stored charge has been removed, but its forward pumping current must be pulsed and not continuous, because drift diodes function with slow carriers. A short current pulse applied in the forward direction charges the P-N junction capacitively, and when the current reverses the accumulated charge is removed from the base region; as soon as it falls to zero the diode opens rapidly, and a high voltage spike can appear through the self-induction of the diode circuit.