The presented experimental results demonstrate the formation of giant amplitude microwave impulses by a chaotic klystron generator operating in autonomous mode. The auto-oscillator is constructed on the basis of a “noisetron” scheme, which contains two five-resonator drift klystrons connected in series in a ring. One of the klystrons operates in a signal linear amplification mode (a linear klystron) and the other - in a signal nonlinear amplification mode (a nonlinear klystron). It has been established that a regime of dynamic intermittency of the “chaos-chaos” type appears in a self-oscillating system at a certain value of a beam current of the nonlinear klystron. In this case, the chaotic sequences of microwave impulses of giant amplitude are formed on a chaotic amplitude background. This type of intermittency is due to the amplitude bistability of the nonlinear klystron.

The results of an experimental and theoretical study of the passage of monochromatic and pulse-modulated microwave signal through a traveling wave tube operating in the nonlinear suppression mode are presented. It was found that the TWT can operate either as a saturable absorber or as a power limiter and these regimes depend on the magnitude of the accelerating voltage and beam current. In the first case, the maximum signal suppression level corresponding to the Kompfner dip is realized in the linear mode, and in the second case - in the nonlinear mode, at a certain input signal power. It is shown that in the case of maximum suppression, a short pulse is formed at the front of the radio pulses. In the nonlinear Kompfner dip mode, the duration of such pulse is decreased with an increase in the power of the input radio pulse. The simulation results obtained using the nonlinear nonstationary theory of a traveling wave tube are in good qualitative agreement with the experimental data.