Design of a Novel Folded Waveguide for 60-GHz Traveling-Wave Tubes

The 60-GHz traveling-wave tube (TWT) prevails nowadays as the amplifier for the satellite communication and electronic countermeasures. The folded waveguide (FW) is a promising all-metal slow-wave structure (SWS) for the 60-GHz TWT with advantages of robust performance, fine heat dissipation, considerable power and bandwidth. A novel FW periodically loaded with rectangular grooves is analyzed for the purpose of gaining higher power and gain. The rf characteristics are investigated by numerical simulation, and the nonlinear large-signal performance of such a TWT is analyzed by a 3D particle-in-cell code MAGIC. Compared with normal circuits, relatively higher continuous-wave power (40–56 W) and similar bandwidth (5 GHz) are predicted by simulation. Meanwhile, the designed operation voltage is 10.5 kV, which keeps the low-voltage advantage of the popular helix TWT competitor. The novel FW will favor the design of a broadband and high-power 60-GHz TWT.