First-order nonlinear effects in travelling-wave tubes

Previous analytical work on travelling-wave-tube (t.w.t.) nonlinear effects has been extended to include the effects of electron space-charge and nonzero beam-coupling impedance. Modulation transfer effects for single- and double-signal operation in a weakly saturated state are discussed and shown to be determined by the design parameters of the t.w.t. Large coupling impedance and low circuit loss are shown to reduce intermodulation signal power and crossmodulation effects.