Design On Key Components Of A W-band Truncated Sine Waveguide Traveling Wave Tube

Traveling wave tube?TWT?is a kind of vacuum electronic devices which are widely used in many fields,especially in the fields of satellite,missile,radar,electronic countermeasure and so on.The slow wave characteristics of slow wave structure?SWS?of TWT play a decisive role in the potential performance of TWT devices.At present,the study of TWT SWS has become the main way to enhance device performance.After a lot of research,a new type of sine waveguide?SWG?SWS was put forward in 2010by the State Key Laboratory of high power microwave vacuum devices.Research shows that it has excellent radio frequency?RF?transmission characteristics and it has the characteristics of simple structure and easy processing.In order to further improve its longitudinal electromagnetic strength and coupling impedance,a new type of truncated sine waveguide?TSWG?SWS was proposed in 2012.In order to fully tap the potential of the TSWG and provide a corresponding solution for later experiments,the key parts of the W band TSWG TWT are designed and optimized.The specific research work is as follows:1.The simulation model of SWS is set up in HFSS and CST and its dispersion characteristics and coupling impedance characteristics are analyzed.The comparison and analysis of the dispersion and coupling impedance characteristics of the conventional SWG SWS is completed.It shows that TSWG SWS with a high impedance coupling than SWG SWS in the range of W and the same voltage.2.A two stage high frequency electromagnetic system?HFES?for high power traveling wave tube in W band is proposed.Then,the input and output structure and the optimal design of the central attenuator are completed.After optimization calculation,the reflection parameter S₁₁ of the HFES is less than-17d B and S₂₁ is less than-45dB in the 90-100GHz band,which indicates that the system has smaller reflection and meets the design requirements.3.The beam-wave interaction of the W band TSWG TWT is calculated by the particle studio of CST.The results show that the output power is greater than 195W in the 90-98GHz frequency band.The biggest output power is 242W at 94GHz and the corresponding gain is 33.9dB.At the same time,the comparison and analysis of the beam-wave interaction with the conventional SWS TWT in the W band is completed.The comparative analysis shows that the output power of the TSWG TWT increased about 16.8%than the conventional SWS TWT under the same electrical parameter settings and the same optimal voltage.4.An optimization idea is proposed for the interaction scheme of a TSWG TWT with a working voltage of 21kV.In the case of reducing the working voltage that three optimization schemes for the main performance parameters are proposed,such as the maximum output power,the high power output bandwidth,the gain,the 3d B bandwidth and other main performance parameters.