Research Of High Power Microwave Power Division Feed Network

In order to obtain higher radiation gain,greater equivalent radiation efficiency and longer operating distance,a very effective way for high-power microwave radiation system is to use high-power microwave large-scale array antenna.If a large-scale waveguide slot array antenna scheme is to be used for high-power microwave transmission,it is necessary to have a power division network that can withstand high-power transmission.The power division network can not only distribute the microwave input power to each branch in a certain proportion,but also satisfy the requirement of the antenna array.The existing power division feed network structure can meet the coplanar requirements of the input and output of microwave array antenna,but the structure is complex,or the structure is simple,but it can not be applied to large-scale high-power microwave antenna array.Therefore,a compact power division feed network with high power capacity is studied in this paper.The main work of this thesis includes the following aspects:1.In this thesis,a mode conversion structure with single input and multiple output is designed based on the working principle of radial waveguide.The characteristics of transition section in the mode conversion structure are studied,and two compact mode conversion structures with power capacity greater than GW are designed.Firstly,a radial waveguide power divider from circular waveguide TM₀₁ mode to multi-channel rectangular waveguide TE₁₀ mode is designed.The simulation results show that the mode conversion efficiency of the power divider is more than 99.52%and the power capacity is more than 1.61GW at 8.4GHz.Secondly,in order to meet the requirements of long-distance transmission of antenna array,a circular waveguide TE₀₁ mode to multi-channel rectangular waveguide TE₁₀ mode with working frequency of 8.4GHz is designed.The simulation results show that the mode conversion efficiency of the radial waveguide power divider is more than 99.98%,and the power capacity is more than3.06GW;2.In order to meet the application requirements of coplanar microwave input and output,compact and high power capacity,firstly,an equal amplitude in-phase feed network structure is designed based on twisted waveguide and curved waveguide.The output ports of the feed network structure are arranged along a straight line,and the electric field polarization direction is also in the same straight line,which meets the coplansr requirements of input and output ports.Secondly,a circular waveguide TM₀₁mode to rectangular waveguide TE₁₀ mode 16 channel equal amplitude and in-phase power division feed network structure is designed by using the same equal amplitude and in-phase power division feed nretwork structure.The simulation results show that the mode conversion efficiency reaches 92.30%at 8.4GHz,the phase deviation of 16channel output ports is better than±3.97°and the amplitude deviation is better than±0.2d B,and the power capacity is greater than 1GW;3.In order to solve the problems of long-distance microwave transmission and low loss,a 16 channel equal amplitude and in-phase power division network structure of circular waveguide TE₀₁ mode to rectangular waveguide TE₁₀ mode is designed.The simulation results show that the mode conversion efficiency reaches 99.99%at 8.4GHz,the phase deviation of 16 channel output ports is better than±4.859°and the amplitude deviation is better than±0.058d B,and the power capacity is greater than 1GW.