Rearch Of Input And Output Structures For W Band Gyro-twt

On the one hand, the traditional vacuum electronic tubes have met enormoustroubles at the band of millimeter wave because of the limiting structure and mechanism.On the other hand, the laser amplifier, which is based on the quanta effect, cannot workeffectively at millimeter wave band. However, the gyrotron based on electron cyclotronmaster can work at this wave band and produce high average power and pulse power.The gyrotron traveling wave tube (Gyro-TWT), as the most important member of thegyrotron family, has received a great deal of attention for its wide band and high powercapability. Moreover, it has been widely applied in the field of communication,millimeter radar, precision guidance, partical acceleration, material processing and soon.In this dissertation,the input and output strctures of Gyro-TWT which work in Wband,including input coupler,input window,output window and output coupling,havebeen studied in details,main efforts are as follows.In the first chapter, a brief introduction to the Gyro-TWT is given.In the second chapter, an improved input coupler whose transitional section istapered has been designed for W band Gyro-TWT. Corresponding theoretical analysisand approximate analysis model are described in detail. The cavity’s approximateparameters are designed by a large number of numerical calculations in Matlab and it iscorrected and checked and by HFSS.In the third chapter, the initial design parameters of input pill-box window for Wband Gyro-TWT have been got by means of theory of equivalent network. The modematching theory is applied in computing the output window for Gyro-TWT. In addition,the precise design parameters of the input and output window are optimized by meansof HFSS emulation.In the fourth chapter, a high efficiency output structure, which is designed for Wband, Gyro-TWT is presented. With the aid of numerical calculation in Matlab, thecontour of the Chebyshev tapered waveguide is got. Based on the optimized resultsfrom HFSS, not only does the improved output structure suppress spurious modes, but it also has good performance on transmitting working modes with acceptable length.In the fifth chapter, a brief summary to the main research work in this paper ispresented.