A Research of 140-GHz Folded Rectangular Groove Waveguide Traveling-Wave Tube

A two-section Folded rectangular groove waveguide (FRGWG) Slow wave structure (SWS) Traveling wave tube (TWT) with large dimension of beam tunnel is studied. Compared with the Folded waveguide (FWG) under the same size parameters conditions, the interaction impedance and center frequency of the FRGWG are higher. The advantage is that a beam tunnel with large dimension can be applied to the FRGWG without the influence caused by signal decrease, reflection and oscillation. The microwave amplification capability based on beam-wave interaction is obtained through the particle-in-cell method. This circuit structure can produce an output power of over 100W ranging from 136 to 142GHz when the operation voltage and beam current are set as 18.4kV and 150mA, respectively, for a 95mm long circuit.