Helix traveling wave tube performance optimization through circuit tapering

Summary form only given, as follows. A helix traveling wave tube (TWT) is the key component in modern satellite communication and electronic warfare systems due to its unique capability of handling more power and gain with wide bandwidth capability. The increasing demand of more power with more gain but less harmonic power from the device sets challenging tasks on the design of the device. The TWT performance needs the estimation of (a) dispersion characteristics such as axial propagation constant and interaction impedance, and (b) output characteristics such as fundamental power, gain, harmonic power, etc governed by nonlinear beam wave interaction.