A high-power wideband traveling-wave tube with stepwise changes in the diameter of the drift channel

Results of the design of a high-power wideband (in the band 8–18 GHz) traveling-wave tube (TWT) with stepwise changes in the diameter of the drift channel are presented. The TWT is stable against self-excitation by a backward wave at high values of the accelerating voltage. It is shown that the output section of the device can be increased by a factor of 1.5 and the operating current can be raised by a factor of 1.3. These increases are attained owing to the 1.27-GHz diversity of the π-type frequencies of sections with different values of the channel diameter and owing to growth of the starting current corresponding to self-excitation by the backward wave. Application of the TWT with the interaction space that has steps of the channel diameter improved the electron efficiency by a factor of 1.2 and increased the output power by a factor of 1.6.