Fast turn off (step recovery) diode

It is also a diode with a PN junction. Its structural feature is that it has a steep impurity distribution region at the PN junction boundary, forming a "self electric field". Due to the fact that PN junction conducts with minority carriers under forward bias and has charge storage effect near the PN junction, its reverse current needs to go through a "storage time" before it can reach its minimum value (reverse saturation current value). The "self electric field" of the step recovery diode shortens the storage time, quickly cuts off the reverse current, and generates rich harmonic components. By utilizing these harmonic components, comb like frequency spectrum generation circuits can be designed. Fast turn off (step recovery) diodes are used in pulse and high-order harmonic circuits.