| Radar is the key equipment for detecting enemy situations in modern warfare.Radar antenna,as an essential for radar system,is used to transmit and receive electromagnetic waves.The electrical performance indexs of the antenna directly determines tactical indicators such as the detection distance and detection accuracy of radar.The structure design of antenna is the guarantee of electrical performance of the radar antenna system.This topic came from the project of a parabolic antenna array.The antenna system adopts a multi-feed form with automatic switching mechanism,which has a complicated structure with high index requirements and a short development cycle.In this paper,the structural design and simulation of the multi-feed radar antenna system are completed by using CAD/CAE,and the engineering of the antenna system is realized.Firstly,based on the working principle of the parabolic antenna,electrical performance parameters of the parabolic antenna are analyzed,and the design points of the parabolic antenna structure are extracted,which provides the basis for detailed design of the antenna structure.Then,according to the requirements of technical indicators,the overall structural design of the antenna system is completed and the modular design of the structure of multi-feed switching system,antenna reflector,bearing platform and pitch mechanism is realized.Two feed automatic switching schemes are compared and analyzed,a kind of multi-feed switching system with a straight-line moving mechanism and locking mechanism is designed.The structural design points of the antenna reflector and the bearing platform are introduced in detail.Using CAD method,UG.NX10 is used to establish the 3D model of the antenna system.The motion analysis module of UG.NX10 is used to complete the motion simulation of the pitching mechanism,and the driving force required by the pitching mechanism is determined,which provides a design basis for the electric cylinder and servo control system.Finally,the external loads of the antenna system are analyzed and calculated,including wind load,self-weight load and snow and ice load.The finite element simulation model of the parabolic antenna and the whole structure is established by using the CAE method and MSC.Patran/Nastran.The static and modal simulation analysis is completed,and the rationality of the structure design of the antenna system is verified.A fixed focus scheme based on finite element simulation is proposed,which completes focusing the feed system with large size and heavy weight precisely.The actual product of the parabolic antenna system meets the requirements of the radar's electrical performance indicators.The design method of parabolic antenna system structure obtained in this paper can provide reference for the other projects. |
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