Development of High-Power Sub-THz Traveling-Wave Tubes with Multiple Sheet Electron Beams

We present the results of studies aimed at development of multiple-sheet-beam microfabricated traveling-wave tubes (TWT) at sub- THz frequency band. The double-tunnel TWT with a meander-line slow-wave structure (SWS) at V -band and the triple-beam TWT with grating SWS at G-band are designed. Technologies for microfabrication of the SWSs are discussed. The results of SWS fabrication and characterization are presented. Multiple-beam electron-optic system is designed and beam transportation in a uniform magnetic field is studied. The results of 3-D PIC calculation of small-signal and large-signal gain are presented.