Research And Implementation Of Wideband High Resolution Frequency Synthesizer

In the 50s of last century, high power microwave has become a hot topic.High power microwave system consists of the following parts: high power microwave source,mode conversion and transmission, transmitting and receiving system.It has been widely used in many fields, such as plasma heating, high resolution radar, directed energy weapons and so on.Many researches on it have been done.High power microwave source is the key to the whole power system, which is equivalent to the whole human body. It is very important to the performance of the whole system. With the further development of the ITER program, the high power microwave source has been put forward higher requirements.The gyrotron has received more and more attention because of the excellent characteristics shown in the field of high power microwave sources.Because the traditional mode converter is difficult to apply in high-order work mode gyrotron,quasi-optical mode converter research based on geometric optics and coupled wave theory is very necessary.In this paper, the theory of quasi optical mode converter for high power gyrotron is studied,Based on the theory of geometric optics and mode coupling, the beam propagation characteristics in the radiator are analyzed.By comparing the working characteristics of the Vlasov radiator and the Denisov radiator, the results show that the Denisov radiator is more suitable for the high power gyrotron mode converter.Then,the focus mirror system, vector diffraction theory and phase calibration algorithm of the mode converter are analyzed.Then, this paper designs a quasi-light mode converter with Denisov radiator, which is based on the Matlab numerical calculation program and FEKO electromagnetic simulation software. It adopts the working frequency of 140GHz, the working mode is high Mode TE22,6 mode.Through the comparison between numerical calculation and electromagnetic simulation, the results show that the theoretical analysis and numerical calculation are accurate.At the same time, the KSA algorithm is used in the phase calibration The field distribution at the output window is analyzed and compared with ideal quasi-Gaussian distribution, the relevant parameter characteristics are obtained,and the results are analyzed.The amplitude and phase of the field distribution in the output window are analyzed, and the parameters such as waist radius, phase distribution,Gauss content and conversion efficiency are obtained. Main contents of this paper:1.A brief introduction of high power microwave technology, and focus on the application of quasi optical mode converter in high power gyrotron.2. Based on the geometrical optics theory and the mode coupling theory, the characteristics and differences of the Vlasov radiator and the Denisov radiator are analyzed and compared ?3. The structural equation of quasi elliptical focusing mirror is derived by using the geometrical optics theory. Analysis of KSA algorithm, the design process of the subsequent mirror.4. The numerical results of Denisov radiator and the results of FEKO are given.The final results are analyzed.