Study on Wideband THz Backward Wave Oscillator Driven by Pseudospark-Sourced Sheet Electron Beam

Abstract

A backward wave oscillator (BWO) based on a double staggered grating (DSG) slow wave structure (SWS) is investigated as a high-power wideband THz source, driven by a sheet electron beam emitting from a pseudospark plasma cathode. Firstly, the DSG SWS is optimized in simulation to have a suitable dispersion characteristic. Then, the BWO with a wideband output structure consisting of a tapered section of DSG and an L-shaped connector is modelled under the operating voltage of 24-38 kV and the current density of 2-5×10 7 A/m 2 (beam current of 1.5-3.8 A). A maximum power of 3.9 kW is obtained, and a wide bandwidth of over 38 GHz (343-381 GHz) is achieved. The impact of fabricating errors of the SWS on the performance of the BWO is analyzed in simulation. The effects of the plasma in the interaction space on the BWO performance are also analyzed, showing that the plasma causes an increase in the oscillation frequency by 1.0%-1.2%.

Sheet Electron Optical System for a 1.03-THz Traveling-Wave Tube

“…Moreover, the SEB devices are easy to process and assemble for the natural electron tunnel, which is very favorable to reduce the processing difficulty of devices operating in a high frequency. Interest in these possible applications and advantages of SEBs has spurred theoretical and experimental studies on SEB devices [6]- [16]. Typically, by employing the SEB, Communications & Power Industries (CPI) developed an X-band klystron with a 5MW output power in 2009 [17].…”