A.G. Shein, M.V. Galats

The mathematical model describing a non-stationary nonlinear operating mode of a backward wave oscillator M - type at presence to twenty signals with various frequencies is described. Presence of a dispersion of slowing down system is considered. Results of numerical experiment of a situation when on an input of the generating device two or three external signals with various frequencies move are resulted. It is shown that process of excitation (generation) and simultaneous strengthening of fluctuations leads to their competition. Competition degree depends on size of input power of external signals and their frequency change in relation to frequency of self-excitation. Nonlinear character of interaction leads to occurrence on an exit of additional fluctuations not only with the frequencies which are a combination of submitted signals, but also to excitation of fluctuations with other frequencies. The process of establishing a stationary largest output status is sufficiently large time, which leads to the impossibility of obtaining a stable process when operating in pulsed mode.