Simulation of Interaction of Folded Waveguide Space Traveling Wave Tubes with Derivative-free Mixedinteger Based NEWUOA Algorithm

In order to study the beam-wave interaction of folded waveguide space traveling wave tube (TWT), a numerical calculation program was developed on MATLAB using an one-dimensional large-signal model and designed mixed-integer based NEWUOA algorithm with penalty function. On this basis, a design example of W-band TWT is given, using different objective function to optimize it with the target of high efficiency and comparing different optimization algorithms. The final results are compared with simulation from CST, where the discrepancy is within 1dB. This proves the reasonableness of procedure and the reliability of algorithm, and a new method is provided for design and optimization, which has best performance.