The Research Of Cold Test On The Interaction Circuit System For Gyro-TWT

Compared with low-frequency microwave source,millimeter wave source has plenty of preferences,such as high resolution,wide band,energy concentration and other advantages,both in the military and civilian.Therefore millimeter wave source has great potential for development.In millimeter-wave band,gyro-TWT is an important microwave signal amplifier,which completes transversal energy transformation between microwave and electron beam.In consideration of the fact that gyro-TWT,compared with the traditional electric vacuum devices,not only has the advantages of high power and high frequency,and in terms of working bandwidth has competitive advantage,gyro-TWT is generally applied in high-resolution radar,communications,electronic warfare,super jammers,directional energy weapons,controlled nuclear fusion and microwave heating and other national defense,scientific research and industrial and agricultural production.The high frequency system of Gyro-TWT generally includes an input coupler,an output window and a high frequency interaction structure,which have a key influence on the device and must be tested before the engineering application to ensure that their performance is reliable.The cold test of the high frequency system of the Gyro-TWT is mainly the test of the transmission reflection performance of the input coupler and the output window,especially the measurement of the transmission and attenuation of each mode in the high frequency interaction structure,and then the dispersion relationship of the high frequency structure.Gyro-TWT generally uses TE01 mode as the working mode,and TE11,TE21 and TE02 are the root causes of instability problems.In order to solve the instability problem,Gyro-TWT generally uses the high frequency interaction structure loaded with dielectric materials.The choice of dielectric material has a great impact on the performance of high-frequency interaction structure,and its electromagnetic parameters must be accurately measured.The existing microwave measurement system is generally based on vector network analyzer which can only convert the coaxial signal to the standard rectangular waveguide TE10 mode through the waveguide coaxial converter.Therefore in order to meet the cold test requirements for the high frequency system of Gyro-TWT,it is necessary to design the mode converter of TE10 to TE11,TE21 and TE02.The main contents of this thesis are divided into the following aspects:1.This thesis has introduced the development and application of high power microwave,especially the development of Gyro-TWT,whose structure and performing principle have also been explained.The thesis has explained the reasons for the instability problems and introduced the magnificent application of the high frequency interaction structure loaded with dielectric material.And the research status of waveguide mode converter for the cold test experimental has also been introduced.2.This thesis has introduced the measurement method of electromagnetic parameters of dielectric materials,based on the principle of transmission reflection method.The ceramic material measurement experiment has been carried out,and the GUI interface has been compiled by MATLAB,which facilitates the processing of the experimental data.3.The converter of TE10 to TE01,TE11 and TE21 have been designed and simulated,and the experiment has been verified to meet the requirement of cold test.4.Design and simulation of the input coupler and output window have been accomplished,and cold test verification experiment have been carried out.