C.W. anomalous-mode operation in silicon planar IMPATT diodes

Silicon planar IMPATT diodes which operate in the Read mode in the frequency range 4.5¿11.5 GHz have been observed to produce c.w. oscillations in the frequency range 0.5¿2.0 GHz. These u.h.f. oscillations commence at a current density of 250 A/cm2 and are accompanied by a 15¿20% decrease in the diode direct voltage. The d.c./r.f. power-conversion efficiency in the anomalous mode is approximately twice that in the Read mode.