Theoretical Research on a Multibeam-Modulated Electron Gun Based on Carbon Nanotube Cold Cathodes

Multi-beam modulation in a carbon nanotube (CNT) cold cathode electron gun is herein investigated in order to develop miniaturized and fully integrated vacuum electron devices. By exposing the electron source to a millimeter-wave signal, the steady-state field emission current density is efficiently modulated by the incident high-frequency (HF) electric field. Our simulation results of this multibeam electron gun show that the field emission current density can be efficiently modulated by different incident frequency millimeter waves. We find that the modulation depth is increased by enhancing the HF input power and anode operation voltage. The modulation frequency and phase of each electron beam can be controlled using a single millimeter-wave source and by simply adjusting the lateral distance between adjacent CNT cold cathodes.