W Band Traveling Wave Tube Grid-controlled Electron Gun Design And Simulation

Vacuum electronics is an ancient discipline, the development of vacuum electron devices has been the decades-old. The first traveling-wave tube was born in1943, and it developed continuously. Up to now, the power of a traveling-wave tube would be kilowatts in continuous wave. The power would be hundreds megawatts when the traveling-wave tube work at pulse wave. The wavelength has also developed to millimeter and sub-millimeter. The continuous development of military electronics industry and military equipment raises ever-increasing demands to the research of traveling wave tube. The high frequency, high power, small size and light weight is the direction of the development modern traveling wave tube. The wavelength of W-band traveling wave tube is3mm, and its frequency is75GHz-110GHz. And it also a hot millimeter-wave traveling wave tube in recent years in China. A good electron gun is essential for the traveling wave tube, the quality of the electron beam of which directly determines the whole tube’s performance indicators. In some high-power traveling wave tubes, the anode voltage would be hundreds of thousands of volts, and thus pulse energy would make the load of pulse modulator be large. In this condition the pulse power would become large and heavy, and which would limit the mobility of the big power traveling wave tube. The gated electron gun solved this problem.In this paper, we did theoretical studies deeply on the traditional Pierce electron and the gated electron gun. And then we designed a gated electron gun which worked in W-band traveling wave tube. The work of this paper follows:First we studied the electron optics of high current and weak current, and then we did depth analysis of the Pierce gun and gated gun based on high current electron optics. We pointed out three methods which used to design the basic no-gated electron: the traditional method of Pierce, Vaughan integrated iterative method, long-rang electron gun designing method.We used Vaughan integrated iterative method to design W-band gated electron gun and get its basic structure. We used ORION software to simulate its basic structure, and after constantly adjust we finally get a good gated electron gun which we need. At meantime we also used CST software to verify the ORION simulation results, which provided a theoretical basis for the design and processing of gated electron gun.Finally, we processed the gated electron gun and then assembly it to the W-band. traveling wave tube. We also did the experimental test.