Research On Methods Of Electromechanical Coupling Of Radar Antennas

The antenna structure distortion by external loads will influence the electrical performance of the antenna directly.Therefore,it's very important to establish the electromechanical coupling model and study the variation of the electrical performance under the structure distortion for antenna design.Based on the numerical simulation method,the electromechanical coupling method of the flat array slot antenna which is used in airborne or missile borne radar was studied in this paper.The main contents completed as follows:(1)Research on electromechanical coupling method of antenna under static load.The key of the electromechanical coupling analysis based on numerical simulation is the data transfer of different physical fields.According to the characteristics of deformation simulation and electromagnetic simulation,three electromechanical coupling methods are proposed.The first one is based on the grid transfer method.The grid transfer of different physical fields is realized by extracting the surface mesh of the deformed structure,which ensures the high accuracy of the electromechanical coupling method.The others are based on the entity transfer method.The entity transfer is realized by extracting the deformed mesh and reconstructing the deformable entity,which can be used to analyze the electromechanical coupling problems of complex models by multiple electromagnetic simulation software.(2)Experimental design and validation of antenna electromechanical coupling method.Based on the principle of the antenna radiation and the plane near field tests,the electromechanical coupling experiment scheme of the flat array slot antenna is designed.Then the antenna is processed and its electrical performance is measured when the antenna structure is distorted or not distorted.The experimental results show that the electromechanical coupling simulation method has high-accuracy in this paper.This method has great significance in engineering,and the result provides a reference to antenna designers.(3)Research on electromechanical coupling method of antenna under random vibration.For the normal distribution of random vibration process,an equivalent method based on the relevance to displacement response is proposed to calculate the effect of random vibration on the slotted waveguide arrays antenna gain.The application conditions of this method are derived by Taylor expansion.The numerical simulation and experimental results for a broadside slotted waveguide antenna show that the error of this method is less than 0.1dB,which proves the correctness of this method.The influence of random vibration on gain is calculated quickly and accurately.This method greatly improves the computational efficiency and saves computation time.