Research On Slow-wave System Of Multi-beam Traveling Wave Tubes

Traveling wave tubes are widely used in various types of electronic devices such as radar, communications, remote sensing and electronic counterwork. Compared to multi-beam klystron and single-beam traveling wave tube, multi-beam traveling wave tube is a new high power microwave vacuum device with the advantages of wide bandwidth, low working voltage, and light weight.Slow-wave structure is the key part of traveling wave tubes, and it is the place where electrons exchanges energy with electromagnetic wave. The bandwidth, the gain and the output power of traveling wave tubes are mainly decided by slow-wave system. In the paper, the slow-wave system of multi-beam traveling wave tube was studied, and our researches are mainly focus on the following aspects:(1) The slow-wave structure of multi-beam traveling tube was designed, and the high frequency characteristics were analyzed by equivalent circuit method and electromagnetic field method in this paper.(2) The cold test characteristics including the dispersion and interaction impedance of multi-beam traveling tube were studied, and the principle, the model, the measurement method of cold test characteristics were all analyzed. Some parameters that affect the dispersion and interaction impedance are also analyzed in the paper.(3) The beam-wave interaction of multi-beam traveling wave tube was studied. The multi-beam electron gun, the periodic permanent magnetic focusing system and the wave-guide were desiged. Meanwhile, the produce of particles, the output power, the process of bunching particles by PPM system and beam-wave interaction were also simulated by particle-in-cell method.(4) The special three-dimension software for the design of multi-beam traveling wave tube was developed. The design method, the design process and the method of the software were all introduced in the paper.As a new type of high power microwave vacuum device, the technique of multi-beam traveling wave tube is immature. The slow-wave system of multi-beam traveling wave tube was studied in details in the paper, and the results show that the multi-beam traveling wave tube is a novel promising vacuum tube with high power. The studies in the paper can provide some guidance to the design and test of multi-beam traveling wave tube.