| Traveling wave tube(TWT),as a microwave electric vacuum device of linear beam,has the characteristics of high power,wide bandwidth and high efficiency.In addition,because of its small size and long service life,it is widely used in satellite communication,radar,electronic countermeasures and other fields,and plays an important role in military industry.With the rapid development of science and technology,the need for high-wave segment,high-power and high-efficiency devices is increasingly urgent,so it is of great significance to accelerate the research of high-wave segment,high-power and highefficiency of TWT.Research on tube fabrication of millimeter band TWT is weak,especially E-band(60~90GHz),microwave communication transmission rate is high,transmission interference is small,bandwidth resources are rich,so it is favored by researchers.The traditional traveling wave tube mainly includes helix TWT and coupling cavity TWT.The performance of helix TWT in power capacity and heat dissipation is poor,and the operating bandwidth of coupling cavity TWT is narrow.The proposed folded waveguide TWT effectively makes up for the shortcomings of both,combines the advantages of them,and it is easy to process.Therefore,it is of great practical value to study the high-power folded waveguide TWT in the E-band,especially the 81~86GHz band as the uplinks of communication satellites.According to the demand of the subject,this paper studies and designs the two Eband hundred-watt TWT,using regular folded waveguide and ridge loaded folded waveguide as a slow wave structure(SWS).Design requirements within the operating bandwidth of 81~86GHz,the saturated gain of the tube is greater than 30 dB,the output power is greater than 100 W,and the electronic efficiency is greater than 4%.The regular folded waveguide TWT is processed and tested.The experimental results show that the design objective is basically achieved.The main work is as follows:1.The folded waveguide type slow wave system were studied in depth.The theory of equivalent circuit was used to analyze the dispersion and coupling impedance characteristics of SWS,and the influence of various structural parameters on the highfrequency characteristics of SWS was analyzed by combining with HFSS simulation.Then,the beam-wave interaction was calculated by FWGTWT4.0 large signal program,and the design scheme of slow wave line was given.2.An electronic optical system matching with the regular folded waveguide TWT in E-band was designed.The electron gun was a Pierce gun without a gate,and the focusing system was periodic permanent magnet focusing(PPM).The Opera simulation software was used to optimize the design.Finally,the result that meets the requirements was obtained.3.The transmission system of E-band TWT was designed.The design theory of attenuator,transition waveguide and energy transfer window were introduced,in which the attenuator adopted a new E-plane gradient wedge structure,the transition waveguide adopted a hyperbolic gradient arc structure,the energy transfer window selected a box window.And the simulation results show that the voltage standing wave ratio of attenuator,transition waveguide and energy transfer window was within a reasonable range.4.The above parts were processed and assembled to complete the assembly of the whole tube,and the physical drawing is given.The output power,gain and flow rate of the prototype tube were tested,and the experimental results were analyzed in order to provide experience for subsequent tube manufacturing. |
PDF Full Text Request