Design And Experiment Of Output Window For EIK In W-band

EIK(Extended Interaction Klystron), appeared in the 1950 s, developed fast in the 1970 s. It combines the slow-wave line and resonator structure and has two features. First it works more stable, more efficient and then it provides higher power output. EIK device plays a very important role in the military microwave electronic systems, as well as anti-jamming system. Our study has just started, so developing EIK is significance.Output window, as an important part of vacuum electron devices, not only need a high performance of gas tight, but also can take the force of atmospheric pressure between the vacuum and air environment and it also need a large power capacity. As Vacuum Electron Devices work in higher frequency, and smaller size, the requirement of output window become more complicated. Facing with the growing popularity of high-power devices, it is necessary to withstand the impact of high power under transmission conditions, but also fight against the higher power in a smaller size. The output window develops in contradiction. Because most damaging of vacuum electronic devices are caused by failure of output windows so the quality of an output window determines the quality of the entire vacuum electronic devices, and the research of output window is significant.This paper studies the output window. Based on the theory, we studied the danger of secondary emission, and discuss the principle of secondary emission, and then gives some general solutions. Selecting the appropriate window material and using CST software, we designed a general pillbox window for W-band and a special pillbox window. The special one has a bandwidth of 4.55 GHz from 92.64 GHz to 97.19 GHz. Then we discuss the effects to the transmission when parameters changes, in order to make sure the standard for the processing accuracy. The output window was manufactured and tested on a vector network analyzer. The cold test results were a little different compared with the simulation results. Due to the cold test, we studied the influence of the ghost mode, and concluded that the asymmetric structure could motivate the ghost mode. Then we do thermal analysis to give different power capacity of windows. Starting from the heat equation, gives a high efficiency power output window structure with larger capacity. From the question of power capacity, we gives double material disk windows output window structure near 94 GHz with good transmission efficiency. At last, we give the prospect of double material disk windows.