Research On V-Band High Power Helix Traveling Wave Tube

The helix TWT has a very broad application field,such as electronic countermeasures,satellite communications.,the reason is that it has lots of advantages such as wide operating band,and large output power.As the craftsmanship level are progressing,the operating frequency of the helix traveling wave tube has been increased to the V-band and it plays an important role in communication.Therefore,it is of great significance to study the V-band helix traveling wave tube.This article has carried out research around the V-band(52GHz?62GHz)helix TWT,and completed the design of the interaction circuit and the electronic optical system.Research on high frequency structure of V-band helix TWT.According to the design goals,the CST simulation software was used to simulate and design the V-band helix TWT and analyze the influence of different parameters on the high frequency characteristics,then we can obtain the most optimized slow-wave structure parameters.Finally,the large signal software ORION is used to study the beam-wave interaction and give the design scheme of the helix traveling wave tube.To avoid the generation of reflection oscillation and increase the power,this thesis adopts the cutting and concentrated attenuator technology.When the uniform pitch scheme is adopted,the output power and efficiency of the traveling wave tube fail to reach the expected goal.Therefore,the pitch jump technology is used to this paper.The simulation results reveal that under the condition of 14800 V voltage and 100 mA current,the minimum saturated output power in frequency band is 282.5W,the minimum electronic efficiency is 19%,and the minimum gain is 43.8dB,which has reached the goal of this paper.In order to visually study the BWO in the TWT,the designed traveling wave tube was simulated by particle simulation using the CST PIC module.From the calculation results,it can be seen that the tube works stably without oscillation.Research on electronic optical system of V-Band helix TWT.First,an electron gun matching the V band helix TWT was designed by software CST.The theoretical value of the structure size is obtained by the calculation program written by Vaughan iterative algorithm,and then the parameter scanning was set to optimize the structural parameters.Then,a circular electron gun which meets the requirement is designed.Based on the working parameters of voltage,current and so on,the focusing system is studied and designed.According to the calculation method of PPM structural parameters,the axial magnetic field and period can be calculated.Then,the structural parameters can be optimized by using CST software.Finally,the optimized circular electron gun and the periodic permanent magnet focusing system are combined to simulate,the transmission rate of the electron beam is 100%.Research on a new Sine Waveguide Slow-Wave Structure.Based on the traditional SW-SWS,a new sine waveguide slow-wave structure which has double tunnel is proposed.When the size of the slow-wave structure is basically the same,the high-frequency characteristics of the two slow-wave structures are calculated in the CST and HFSS software.The calculation results show that the dual-tunnel SW-SWS has higher coupling impedance and higher working frequency band.In addition,the PIC simulation results reveals that under the same operating voltage,compared with the traditional sine waveguide traveling wave tube,the maximum output power of the DTSW-TWT has been increased by 113%,and the output power and gain bandwidth have been significantly improved.This paper has completed the design of the V-band helix traveling wave tube.After adopting the scheme of negative pitch jump,the output power increased to 282.5W,and the maximum output power of the tube at 56 GHz is 301 W,which achieve the goal of high-power output.This article also carried out research on the electron gun and focusing system,and finally designed a circular electron gun with a voltage of 14800 V,a current of 100 mA,and a waist radius of 0.07 mm.The electron gun and the periodic permanent magnet focusing system were jointly simulated,the transmission rate of the electron beam is 100%,which realizes the good transmission of the electron beam in the traveling wave tube.Finally,a dual-tunnel sin waveguide slow-wave structure that can work in the terahertz band is proposed.Under the premise of the same structure size and working voltage,the new structure has a higher output power,and the maximum can reach 405 W.Therefore,the dual-channel sin waveguide traveling wave tube has significant advantages in the Hertz frequency band.