Negative dynamic conductivity in diode structure with the cone cathode

The possibility of using diode structures with a cone cathode for negative dynamic conductivity generation and consequently high frequency oscillation generation in a shortwave part of the millimeter range and in the submillimeter range is investigated. The principle of such diode operation is similar to that of the solid-state injection-transit diode, where to generate oscillations or to obtain negative conductivity it is necessary that the electron transit time between the cathode and the anode is approximately 0.75 oscillation periods