Dielectric Output Windows Of High Power Microwave Feed

With the development of HPMW(High Power Microwave ),the power of microwave is higher and higher,but the destruction of microwave windows is more and more outstanding.Throuth the analysis of the near-field destributing,we can conclude conditionally that the trend of near-field distributing of Gaussian aperture field is descendent.We can make use of this characteristic to solve the problem of destruction of microwave windows.The effect of the far-field radiation pattern because of the half-shell microwave windows is analysed by the method of Dynadic Green's function;the effection of far-field radiation pattern because of the cap-shape windows is also analysed by the method of double near-field calculation.By the method of double near-field calculation three shape windows has been analysed,these three windows are convex,concave and conves concave,and the effect of far-field radiation pattern and the change of gain and the ratio of energy within 3db have been investigated.In the end of the paper the windows made up of two equating phase surface is a solution for the Gaussian aperture field.