On the assessment study of small signal gain analysis of helix type traveling wave tube with pierce parameters

The main idea of this study is to investigate the small signal gain analysis of the helix type Traveling Wave Tube's (TWT's). Dispersion equation of the TWT is discussed and the behavior of propagation constants of the helix TWT structure is expressed when beam-wave interaction occurs. All possible waves or modes which play important role in the amplification process are considered. The effects of loss due to interaction circuit, space charge effects and beam velocity variations are taken into account when solution of the dispersion equation and TWT gain characteristics are carried out. Fundamental aspects of the TWT small signal gain analysis with Pierce parameters such as b (velocity parameter), QC (space charge parameter), d (cold tube circuit loss) are examined. Some significant figures are obtained to express the behavior of the gain with respect to Pierce parameters. It is noted that Pierce small signal theory gives important information to investigate the gain characterization of the TWT considering natural effects of beam velocity, circuit loss and beam-wave interaction.