Studying the Output Two-Gap Cavity of Three-Barreled Two-Band Multibeam Klystrons of the Ku Band

The paper presents the results of three-dimensional modeling of a two-gap output cavity of three-barreled multibeam klystrons. The coaxial output of energy has a simple design and allows achieving the simultaneous output of microwave energy at two frequ encies of the Ku band, one of which is in the beginning of the range and corresponds to the antiphase (π) type of oscillations of double gridless gap, and the second of which corresponds to the inphase (2π) type in the end of this range. It is shown that the application of the developed cavity in a three-barreled design of 57-beam klystrons with a general number of beams N = 57 allows, at working on a inphase type of oscillations, obtaining the level of continuous output power of approximately 3 kW in the amplification band of 100 MHz at an accelerating voltage of 5.4 kV and current density in a single beam of 35 A/cm 2 . It is shown that the self-excitation of a klystron cavity on the antiphase type of oscillations is absent. This is reached due to the presence of metamaterial in the hybrid design of the output cavity and as a result of optimal selection of the parameters of double gaps that avoids the appearance of interaction regions with the negative zone of electron-type conductivity. It is demonstrated that the frequency of the inphase type of oscillations can be adjusted (within 12%) using the longitudinal ribs introduced into the volume of the cavity.