Step recovery diode

It has a variety of uses in microwave (MHz to GHz range) electronics as pulse generator or parametric amplifier.

The first published paper on the SRD is (Boff, Moll & Shen 1960): the authors start the brief survey stating that "the recovery characteristics of certain types of pn-junction diodes exhibit a discontinuity which may be used to advantage for the generation of harmonics or for the production of millimicrosecond pulses".

This stored charge depends on Quantitatively, if the steady state of forward conduction lasts for a time much greater than τ, the stored charge has the following approximate expression Now suppose that the voltage bias abruptly changes, switching from its stationary positive value to a higher magnitude constant negative value: then, since a certain amount of charge has been stored during forward conduction, diode resistance is still low (i.e. the anode-to-cathode voltage VAK has nearly the same forward conduction value).

The principle of the DSRD operation is similar to the SRD, with one essential difference - the forward pumping current should be pulsed, not continuous, because drift diodes function with slow carriers.

The following two books contain a comprehensive analysis of the theory of non-equilibrium charge transport in semiconductor diodes, and give also an overview of applications (at least up to the end of the seventies).