Research of Efficiency Enhancement in a Helix TWT with Simulated Annealing Algorithm

Helix traveling-wave tubes (HTWTs) are high-gain high-power broadband vacuum electron devices. Due to their broad bandwidth, HTWTs have been widely used in telecommunication application and electronic warfare systems. The electron efficiency at high frequencies of the operating band has been a major concern with these devices, especially with space HTWTs. Therefore, in this paper, the computational optimization technique of simulated annealing, which has the advantage over conventional optimization techniques, such as a steepest-descent optimization algorithm in that a global optimum solution was be determined, was used to optically design the helix pitch profile. Computational results were presented and discussed. It is shown that the electron efficiency and output rf power can be effectively improved through numerical simulation. In the near future, the method will be utilized to study suppression of harmonic wave and linearity in the entire operating band.