Research On Traveling-wave Tube With Rectangular-ring Vertex Double-curve-bar Slow Wave Structure

Modern electronic technology has higher requirements for traveling wave tubes.With the development of traveling wave tube towards high power,high frequency and miniaturization,the traditional helix traveling wave tube is difficult to meet the demand.In terms of power,the back-wave oscillation of the traditional spiral traveling wave tube is serious when it exceeds10 k V,which limits its power.In terms of working frequency and miniaturization,with the high frequency of traveling wave tube,the size of slow wave structure gradually decreases,which makes the requirements of modern high precision machining more stringent.Therefore,the new slow wave structure which meets the development needs has become the research focus.In recent years,the sheet beam has been developed rapidly.Compared with the circular electron beam,it has the advantages of low charge effect and high efficiency.Therefore,the slow wave structure of sheet beam has become an important research direction of traveling wave tube.Therefore,this paper presents a new type of slow wave structure,namely rectangular-ring vertex double curved bar slow wave structure.In this paper,HFSS,CST and other simulation software are used to study the new slow wave structure.The main research contents of this paper are as follows:1.A slow wave structure of rectangular-ring vertex double curved Bar is proposed on the basis of ring-double-bar and rectangular-ring vertex double bar.By HFSS and other three-dimensional simulation software,the high frequency characteristics of the rectangular-ring vertex double curved bar slow wave structure are analyzed,and the influence of the structural size parameters on the high frequency characteristics is studied.The high frequency characteristics of the rectangular-ring vertex double bar are compared and analyzed.The results show that the new structure has higher interaction impedance,and its interaction impedance is increased compared with the rectangular-ring vertex double bar,which is more conducive to the improvement of the output power of the traveling wave tube.2.At the same time,the transmission characteristics model of Ka-band rectangular-ring vertex double curved bar is established in CST,and the input and output matching structure of coplanar coupler and coaxial line is designed.The results show that in Ka-band,its S₁₁is less than-20 d B,and the model has good transmission characteristics.3.The beam-wave interaction of Ka-band traveling wave tube with rectangular-ring vertex double curved bar slow wave structure is studied.A traveling wave tube model of rectangular-ring vertex double curved bar slow wave structure is established in CST particle studio.The beam-wave interaction is analyzed by PIC solver.The analysis results show that the output power,gain and electronic efficiency of the traveling wave tube at 33.5 GHz are1410 W,41.5 d B and 29.37%.The Power is 30.55%higher than rectangular-ring vertex double bar.4.At the same time,A novel rectangular-ring double curved bar is studied in Q-band.First,the influence of the size parameters of the rectangular-ring double curved bar high-frequency characteristics is analyzed.The second is to explore the transmission characteristics of the input-output matching method of the coplanar coupler using the model.At the same time,the transmission performance of the rectangular-ring double bar is compared.It provides a basis for the traveling wave tube design of this slow-wave structure.