Effects of the attenuator on the nonlinear phase distortion of a traveling-wave tube

An experimental and theoretical examination indicates how the non-linear phase distortion of a traveling-wave tube is affected by relevant factors, especially the circuit loss. The effect of the loss is found to be about ten times as large as theoretically predicted, An approximate formula is derived for the phase distortion of a TWT with an attenuating central section, and comparison is made with experimental values.