X-band High Efficiency And Low Magnetic Field Of High Power Microwave Source

This dissertation presents a way to improve the efficiency and output power of RBWO and to reduce the focusing magnetic of the RBWO. In order to verify the correction of this method, I use the Particle-in-Cell (PIC) software MAGIC to simulate the RBWO of this kind of structure. Firstly, the author analyses the cold characters in details and concludes the factors which limit the output power and efficiency of RBWO and provides a method to improve the efficiency and the output power and to reduce the focusing magnetic of RBWO based on the researching work. In the process of researching, the author develops a fast method to calculate the cold characters of the RBWO which is named impulse response method based on the numerical calculation of EM. Secondly, in order to research the mode contention which probably exists in the improved big dimension RBWO, the author research the conditions which the mode contentions exist in the RBWO and provide the preliminary ways to prevent the occurrence of mode contentions. At last ,the author uses the PIC tool of MAGIC to simulate the HL-RBWO of new structure, the result is consistent with the theoretical prediction of the three-dimension linear theory and nonlinear theory of RBWO.The main jobs and achievement is the following:1. Use the approximated-field theory to solve the dispersion relation of corrugated cylinder waveguide.2. Develop a new numerical fast method to calculate the cold character of RBWO which is named impulse method.3. Research how to depress the mode contention of large dimension RBWO.4. Deep research on how to improve the efficiency and output power and to reduce the focusing magnetic of RBWO.5. Provide a new structure of HL-RBWO and use the MAGIC to simulate it. From the result of the simulation, we get some useful result.The aim to research the cold character of RBWO is to reveal the relations between the structure and the output power ,efficiency and the focusing magnetic. In fact, the structure of device decide the output power, efficiency and focusing magnetic. To adjust the parameters of the beam is to research the optimum output power of given structure. This dissertation present a new structure of RBWO and use the MAGIC tool to simulate it and it is a good reference for further research on improving output power, efficiency and reducing the focusing magnetic.