Development of <i>G</i>-Band Continuous-Wave Folded Waveguide Traveling-Wave Tube

A detailed development of a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$G$ </tex-math></inline-formula> -band continuous-wave (CW) traveling-wave tube (TWT) with a 160-GHz <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\cdot \text{W}$ </tex-math></inline-formula> product of bandwidth power is reported in the present work, in which the electron optics system (EOS), the tapered phase velocity folded waveguide (TPVFW) slow wave structure (SWS), the modified pill-box window (MPBW), and experimental results are described. The prototype of the proposed TWT is fabricated with optimized structural parameters obtained by particle-in-cell (PIC) simulations. Moreover, the experimental results show that TWT with 27-W output power at the frequency of 220 GHz at 100% duty cycle is obtained at the operation voltage of 17.1 kV and the current of 62 mA. The proposed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$G$ </tex-math></inline-formula> -band TWT will have broad applications in far-distance high-resolution imaging and large communications capacity.