A pitch distribution in slow-wave structure of STWT using Cauchy mutated cat swarm optimization with gravitational search operator

Space traveling-wave tube (STWT) is a special power amplifier used in the space technology field to perform high-power conversion of signals; the pitch distribution is core parameter in slow-wave structure to ensure energy exchange between the electron beam and electromagnetic wave. A novel Cauchy mutated cat swarm optimization with gravitational search operator (GS-CMCSO) is proposed and applied to slow-wave structure design of STWT, electron beam efficiency is used as the objective function, and 1-D CHRISTINE code is introduced to obtain the output value of STWT, the pitch distribution to obtain best beam efficiency can be calculated. Experiments are carried out based on GS-CMCSO; quantum particle swarm optimization (QPSO) and Cauchy mutated cat swarm optimization (CMCSO) algorithms are introduced for optimization performance comparison. The experimental results demonstrate that the best beam efficiency (42.6%) generated by GS-CMCSO is larger than those of CMCSO (40.5%) and QPSO (34.9%); when the STWT is saturated, the output power and gain optimized by GS-CMCSO are excellent. Thus, the proposed method is very suitable for pitch distribution optimization in the slow-wave structure of STWT and performs better than those on QPSO and CMCSO.