Investigation on wideband tubes

Ku-band folded waveguide type TWT is fabricated. This particular type of TWT draws attention for its robust structure and easier coupling. The linear theory predicts a gain of 2 dB/cm and a bandwidth 37% at the center frequency of 14 GHz when the parameters of the circuit are b=0.469 cm, l=0.746 cm, h=2.017 cm. A dispersion relation is derived using an equivalent circuit model and is compared with HFSS simulation. The electron beam and its diagnostics, solenoid, RF circuit, and other components are discussed.