Synthesis of radiation spectrum in the relativistic BWO

Summary form only given. Two methods of synthesis the multifrequency radiation spectrum in a high-power relativistic backward wave oscillator (BWO) is discussed. A regime of generation at several close frequencies with the same transverse field structure can be realized in a sectioned system with a stepwise variation of the mismatch between the beam and synchronous wave. In the case of high-power relativistic BWO with the microwave systems representing sections of a corrugated waveguide, a change of synchronism conditions can be provided by variation of the corrugation period. The simulation showed that the sections could operated independently at two different frequencies when the mismatch shift between sections is sufficiently large. The increases of the full system length together with variations of the length of every sections could produce more complicated generation regimes in two frequency bands. For example, monochromatic radiation at one band and stochastic oscillations in another band either the dual-band stochastic oscillations can be realized. In the case of the linear growth of the mismatch at the second section the twofold increasing of the total chaotic spectrum width could be achieved in comparison with regular BWO with the same normalized length.