Influence of silicon doping density on vacuum field emission triode at high frequency range

Silicon FEA will affect the high frequency application of field emission tubes when it works at the microwave frequency range. This article shows that the electron emitting will be influenced by the majority carrier response time in semiconductor silicon. The surface capacitance and delay time of n-type and p-type silicon are calculated by using semiconductor theory. The result shows that the semiconductor conductivity will determine the maximum work frequency of device. The maximum work frequency (no considering other effects such as C_gc, g_m etc.) will be decreased from about 200 GHz to 2 GHz when the resistivity of p-type silicon is increased from 0.1 · cm to 10 cm.