Study On THz Clinotron And High Frequency Loss

Lack of compact and high-power radiation sources is the bottleneck of the development of THz technology. As a widely used microwave power source, BWO is designed of tube electron beam parallel to the surface of slow-wave structure, and in order to prevent electronic being intercepted by slow-wave structure, electron beam has to maintain a certain distance with the surface of the grating. The slow-wave part is a periodic structure, and it has the nature of surface acoustic wave with its thickness of the effective interaction inversely proportional to the frequency, that the high the frequency, the smaller the thickness of the structure.In order to solve the difficulties, BWO is designed to tilt the electron beam, called the clinotron. As a new THz radiation, the clinotron has many unique advantages and broad the application prospect in THz band. This paper studies on the theoretical analysis of the clinotron, and makes a lot of simulation and calculation on the dispersion properties of clinotron and wave-beam interaction aiming at 340GHz. The processing method of mental grating was studied, and the effects of surface roughness on performance of slow wave structure was simulated.Depth study of a single row of rectangular grating slow wave structure, detailed analysis of the high-frequency characteristics, and dispersion characteristics of each size parameters for numerical simulation. The results show that, to meet the bandwidth requirements of the case, you should use a larger gullet gullet depth and width. After a series of comparison and optimization, to give 340 GHz cavity single-cycle structure size oblique injection tube.Based on theoretical analysis of the interaction of clinotron, the working voltage, current and focusing magnetic field related to simulation model were confirmed, and through PIC simulation,the output characteristics were detailed calculated, respectively the influence of electronic injection angle, the size of focusing magnetic field and voltage.The analysis results show that the electron injection angle was particularly important, a slight angle change can significantly change the degree of interaction of the pipe. At the same time, due to the structure characteristics, a small focusing magnetic field can be used. According to the results, when using a smaller magnetic field, the electron divergence is not apparent, the interaction can still be effective. On the contrary, when focusing magnetic field is too large, the electronic excessive compression occurred, thus reduced the efficiency of the interaction.Investigation of the process fine metal grating, and electromagnetic simulation software to simulate the effect of surface roughness on the slow wave structure transmission performance, gain, bandwidth, and so on. The results of surface, the surface roughness of the metal causes the equivalent conductance decreases, affect the transmission performance of the waveguide, and the degree of interaction effect decreased slow-wave structure, the gain and bandwidth of the pipe is reduced.