Simulation of Beam-Wave Interaction of Newly-Designed Two Electron Beams Higher Order Mode Folded Waveguide Slow Wave Structure

A novel type of two electron beams higher order mode folded waveguide (FWG) slow wave structure (SWS) operating at 220 GHz was proposed, comprising four slow-wave line segments connected by attenuators.The dispersion and beam-wave interaction characteristics were theoretically analyzed and numerically simulated with HFSS and CST-PS software.The influence of the three variables, including the kinetic spread, angular spread and voltage difference of electron beams in DC emission, on the output gain was investigated.The simulated results show that significantly depending on the three variables, the output signal in working mode of the proposed FWG-SWS is stable with a gain of 33.1 d B.For example, a kinetic spread greater than 1%, or an angular spread over 0.5° or a voltage difference higher than 0.08 kV all has a major impact on the output gain.We suggest that the proposed FWG-SWS be of some technological interest in devices fabrication.