Novel Rectangular-Ring Vertex Double-Bar Slow Wave Structure for High-Power High-Efficiency Traveling-Wave Tubes

A novel rectangular-ring vertex double-bar (RRVDB) slow wave structure (SWS) is proposed to develop high-power high-efficiency traveling-wave tube (TWT). The remarkable advantages of this novel slow wave circuit are flatter dispersion and significantly larger interaction impedance in comparison with the circular ring double-bar (RDB) SWS. The particle-in-cell simulation of RRVDB TWT shows that, at beam voltage of 25.1 KV, beam current of 0.2 A, the maximum output power of 581.2 W, corresponding to differential small-signal gain of 0.366 dB/mm and electron efficiency of 11.57%, can be obtained for operating frequency of 34.5 GHz; the output power, gain, and electron efficiency of RRVDB TWT are considerably improved compared with RDB TWT. At the same time, size reduction and bandwidth extension are also achieved for the RRVDB TWT.