Rectangular Gate Ribbon Electron Beam Injection Wave Interaction Research

Travelling wave tube (TWT) is the most important type of microwave vacuum tube. It has been frequently used as millimeter wave radar, guidance, tactical and strategic communication, electronic countermeasure, remote sense, radiation measurement and so on. Its performance directly influences the level of the weapon equipments, and it has importantly realistic significance for the study on the new type of high power and short mm-wave traveling wave amplifiers. This dissertation is concerned with the"study on interaction between sheet electron beams and microwaves in rectangular wave-guide grating slow wave system(RWG SWS)". In this dissertation, we have made detailed study on one type of RWG SWS, including the study on high frequency characteristic of double rectangular wave-guide grating slow wave system(D RWG SWS), the large signal simulation of interaction between sheet electron beams and microwaves in RWG SWS and the majorized design of the input and output structure.The development of electron devices especially the current trend of microwave vacuum electron devices were first presented. Subsequently, the research status of TWT nonlinear theory both in domestic and overseas were formulated. I have given the introduction in character and analytical methods of electromagnetism slow wave structure, briefly introduced the correlative software, and then have made theoretical study on DRWG SWS.At the basis of theoretical study, I utilize CST(MWS) and MAFIA software which are electromagnetism calculation software made by CST company to simulate the cold character of w-band in DRWG SWS, such as dispersion character and coupling impedance. The beginning research laid the foundation for latter study.In this dissertation, I focus on using three-dimensional PIC simulation software to simulate the interaction between sheet electron beams and microwaves. Synchronously, I have successfully established correlative calculation model and given the simulation process. In three-dimensional PIC simulation, the sheet electron beams were bunched well and they have given power to electromagnetic wave commendably by seen from the picture of phase-space for all particles. I have elicited the relationship between saturation power and frequency by calculated many times. Saturation power and gain were educed separately as 172.36W and 30.1dB. However, the working voltage is very high because of the high phase velocity in RWG SWS, which cause some difficulty in practice. In the simulation model, focusing of sheet electron beams can adopt wiggler and PCM magnetic field to focusing but the research must be continued in practice.I have preliminary investigated the input and output structure in DRWG SWS. I designed the input and output structure with CST(MWS), and that lead the bandwidth of the double sided shallow groove grating system to 4.8%, while the voltage standing wave ratio (VSWR) bellows 1.5. Generally speaking, in practical application of project, VSWR is expected less than 1.3. In this paper, VSWR working at central frequency is designed in the range of 1.2-1.3, which is achieved the requirement basically. However, suffering from the narrow bandwidth, extending bandwidth will seems to be the direction of research in the future.