SEMITRANSPARENT TRAVELLING-WAVE TUBE Russian patent published in 2018 - IPC H01J25/00 

FIELD: electricity.

SUBSTANCE: travelling-wave tube with an energy input and output comprising transmission lines containing of a waveguide type, with the interaction space in the form of a slow-wave structure containing a spiral, support dielectric rods and a metal shield, with a local absorber made on the basis of a resistance film placed on the support dielectric rods. The resistance film of the absorber is applied in such a way that it is absent on the surface of dielectric rods touching the spiral and on part of the surface of the lateral sides, and is present on the remaining part of the lateral sides of the dielectric rods. In this way, the attenuation inserted by the absorber at the lower frequencies is greater than at the upper frequencies. The attenuation drop is primarily determined by the gap between the resistance film and the spiral. Selection of the gap size may have the effect of ensuring that the reduction in efficiency due to the insertion of the absorber will be minimal, and the insertion attenuation will be sufficient to ensure resistance to self-excitation. The optimal gap is from 0.3 to 0.6 of the dielectric rod height for different TWT designs.

EFFECT: improving output characteristics of a travelling-wave tube while providing resistance to self-excitation, including at the cut-off frequency of waveguides.

2 cl, 7 dwg