Design and Experiment of 4MW Ka Band Sheet Electron Beam TWT

High-power vacuum electron devices (VEDs) are attractive, because of their broad applications, such as advance radars, electromagnetic warfare, and plasma reactors. In this paper, a Ka band mega-watt sheet electron beam traveling wave tube (TWT) is reported. A two-staged rectangular waveguide grating slow wave structure (SWS) driven by a sheet electron beam (20mmx1mm, 164.8kV, 850A, 20ns) is used in this TWT. In order to suppress the self-excited oscillation, a rectangular BeO attenuator is inserted between the two-staged SWSs. The experimental results show that the TWT can produce more than 2MW output power from 34.2 to 35.5GHz. And the maximum output power is 4.24MW at 35GHz, corresponding to the gain of 25.9dB. In the future, the TWT will be used to perform research on biomedical effects and imaging.