Fabrication and Cold Test of G-band Symmetrical Double Slots Coupled-Cavity TWT

In this paper, the fabrication scheme and cold test process of a G-band sheet electron beam symmetrical double slots coupled-cavity traveling wave tube (SDSCC TWT) are presented. The slow wave structure (SWS) of SDSCC TWT presented in this paper is with a 0.85mm x 0.22mm extremely large sheet electron beam tunnel and over 2Ω coupling impedances at the same time. These features of SDSCC SWS permit sheet electron beam to move in a larger transversal area, especially along the short side of sheet beam, and also shorten the interaction length, which are the reasons SCSCC SWS could improve the transmission rate of sheet electron beam. The high frequency (HF) structure of SDSCC TWT is divided into six components to fabricate. Each component is fabricated by CNC milling. The pressure diffusion welding is used to weld the components. The tested -12dB bandwidth is 23.3GHz. The cold test results verify the fabrication scheme is able to achieve the design performance.