Nonlinear Signal Suppression in a Traveling-Wave Tube

The results of experimental and theoretical studies of the passage of monochromatic and pulse-modulated microwave signals through the traveling-wave tube operating in the mode of nonlinear suppression are presented. It is established that, dependent on the value of the accelerating voltage and beam current, the tube may operate either as a saturable absorber or as power limiter. In the first case, the maximum level of signal suppression corresponding to the Kompfner dip occurs in the linear mode, while it occurs in the nonlinear mode, under a certain power of the input signal, in the second case. It is shown that, in the case of maximum suppression a short pulse is generated at the front of the radio pulses. In the mode of a nonlinear Kompfner dip the duration of such pulse decreases as the power of the input radio pulse increases. The calculation results obtained by the nonlinear transient theory of traveling-wave tube are in good agreement with the experimental results.