Design and Simulation of High-Power Higher Order Mode 340-GHz Extended Interaction Klystron

In this article, in order to realize high-power terahertz (THz) transmission, a 100-W class extended interaction klystron (EIK) operating at 340 GHz on a higher order mode (HOM) TM
₃₁
is designed. The dispersion curve and quality factor of the cold cavity are analyzed, and it is proved that there is no mode competition and self-excited oscillation in the high-order cavity. Three-dimensional particle-in-cell (PIC) simulations predict that EIK achieves 39.4-dB saturation gain and 113.4-W output power at 337.6 GHz driven by an electron beam at a voltage of 24 kV and a current of 0.217 A. The electronic efficiency and bandwidth are 2.17% and 0.32 GHz, respectively. The feasibility of manufacturing is analyzed from the aspects of manufacturing tolerance, ohmic loss caused by surface roughness, and beam radius. EIK operates in TM
₃₁
mode, significantly reduces manufacturing difficulty, and is a promising method of producing high power. EIK works in TM
₃₁
mode, which greatly reduces the manufacturing difficulty and is a promising method for generating high-power microwaves. The proposed EIK can be applied to THz spaceborne communications.