Application research on grading ring in high power microwave antenna window

In order to improve the power capacity of the high power microwave (HPM) radiation antenna, a radiation antenna window with grading ring is designed. With grading ring in antenna window can avoid dielectric window breakdown effectively. Changing the electric field distribution of the dielectric window leads to the electron trajectory change. CST simulation shows that when the grading ring is perpendicular to electric field, it does not affect the radiation of the antenna. According to the output microwave characteristics (TM01 mode) of HPM device (BWO Backward-wave Oscillator), the BWO experiment shows that the width of the output microwave changes from 45 ns to 100 ns with a beam voltage of 3 MV, a beam current of 10 kA, and an efficiency of 30%.