Optimization And Simulation On X-band Coaxial Multibeam Klystron

In this paper, the author analysised and simulate X-band coaxial MBK theoretical which work in TM310 mode. Combined with CST software, the author features a coaxial resonator simulation and theoretical research, and tested the cold cavity parameters. For X-band klystron injecting more theoretical studies, including the basic principles of the klystron, a small signal theory, large-signal theory, resonator theory, the collector structure design. Which analyzes the space charge wave theory, field wave interaction, as well as electronic original disk theory. According to the theory to calculate the resonant cavity structure parameters, electrical parameters, and analyze its wave interaction and output power spectra. In addition, also studied the causes of the phenomenon of virtual cathode pole collection, propose effective solutions, successfully suppressed the electronic reflow phenomenon.In theory, the combination of X-band CST software interaction klystron operating characteristic segments studied. Which the TM310 mode of study is divided into three parts: First, calculate the characteristic parameters of the cavity, such as operating frequency, characteristic impedance, quality factor, etc., and to analyze the structure and parameters of coaxial resonator cavity drift tube structure parameters of the software by CST relations between; the second is the analysis of electrical parameters klystron,according to the voltage, current density and high-frequency input signals to calculate the output power, frequency. Adjusting the input, output cavity and coupled pore structure, so that the corresponding appropriate operating parameters; Third Analysis TM310 mode, X-band RF cavity field distribution, and calculate the electric field gap,the coupling coefficient and so on.In the simulation, the use of three-dimensional particle simulation software development since independence-CHIPIC software, the entire tube simulation.Relations klystron configuration parameters, electrical parameters such as output frequency, power and gain. The output power is increased by increasing the coupling hole radius from 33.6KW to 39 KW, by increasing the loss material, self-excitedoscillation suppression chamber, the value from over 3000 down to 20 or less. And expand the klystron bandwidth. Six cathodes emission beam current, voltage 21.5A, the total current(current density 3.58E5A/m2). Input frequency of 9.75 GHz,a high-frequency signal power of about 2.5W, measured output frequency 9.75 GHz,power peak power of about 100, the average output power of 45 KW. Efficiency of about14%, a gain of about 42.6dB, and 200 MHz bandwide.In addition, this paper based on the test results sniper CST software, studiedthe TM310 mode, and the introduction of shorting bar to solve the problem of the polarization mode. Input, output cavity field distribution distortion occurs, thispaper introduces the tuning rods, not only to restore uniform distribution, but also increases the output power. CHIPIC momentum through the software, real-timeobservation of particles instantaneous phase diagram electronic reflow process, analyze and resolve this phenomenon.