Research on beam‐wave interaction of EIK in THz band

Abstract

AbstractThe extended interaction klystron, which has high power, high efficiency, and high gain characteristics in the millimeter wave and terahertz frequency bands, is a compact electric vacuum device. In this paper, a multisection coupling cavity, each of which consists of multiple gaps, is proposed as the high‐frequency circuit of the extended interaction klystron and the beam‐wave interaction is studied. According to the space charge wave theory, the electronic conductance in the multigap cavity is studied. With the operating frequency of 225 GHz and the electron beam voltage of 12 to 13.65 kV, the system can achieve a stable operation. In the multigap cavity, the amplitude of electronic conductance increases with gap number. It means that the large gap number can enhance the beam‐wave interaction. The beam‐wave interaction is studied by establishing the impedance matrix of the multigap coupling cavity and using the electronic disk model. Under the condition of the electron beam voltage of 13.03 kV, the current density of 65A/cm2, and the signal frequency range of 225.63 to 225.67 GHz, the electron conversion efficiency is about 6.5%. Compared with the particle‐in‐cell simulation, the theoretical research results agree well with the simulation results. It verifies that the method in this paper is accuracy and reliability.