Theoretical Study of a Novel G-Band Sheet Beam Slots-Loaded Coupled-Cavity Traveling Wave Tube

In this article, the design of a novel symmetrical double slots coupled-cavity (SDSCC) traveling wave tube (TWT) operating in
${G}$
-band is presented. The novel slow wave structure (SWS) suits sheet electron beam and has a large sheet beam channel and high coupling impedance. The novel structure shows great potential in high-power terahertz amplifier field. The dispersion characteristics are studied by both theory and simulation. An equivalent circuit of SDSCC SWS is built. The coupling impedance and electric field of operating mode are simulated. A suitable input–output structure is designed for this novel SWS. The transition characteristics are exhibited. The beam-wave interaction process is also simulated. The peak output power arrives at 384 W at 218 GHz by the usage of a sheet beam with 26.2 kV and 300 mA. The average dc current density in the sheet beam tunnel is around 160 A/cm2. The spectrum of the output signal is pure, and the risk of mode competition is very low.