Shaped Design And Surface Prediction Of Reflector Antenna

The large space deployable antenna is the indispensablely key equipment in the field of space and national defense fields such as, satellite communications, earth observation, remote sensing, deep space exploration. The development trend of the reflector is high frequency, high gain, high positioning accuracy and large diameter. The performance of antenna is not only determined by the electromagnetic factors, but also by the mechanical structural factors, which involves in electromechanical coupling issues. In order to meet the requirements of high frequency and beam-forming of antennas, new challenges of maintaining the reflector accuracy is proposed, which makes electromechanical coupling relationships more prominent. To ensure the electrical performance of the antenna, this paper studies the shaped design and surface prediction of the reflector. The main work and results are as follows.Firstly, the coupling relationship between the displacement field and the electromagnetic field of the antenna reflector was studied. This paper introduced the basic electrical parameters and aperture integration of the parabolic antenna. The mesh division method of finite element method was introduced into the current aperture integration. Combining the shape function with the quality points subdivision method, the paper established the corresponding relationship between surface error and the triangular element phase error terms of aperture plane. The electromechanical coupling property analysis of truss deployable reflector antennas was carried out. Compared with the traditional method, the proposed method can reduce the number of grid greatly in electromagnetic field calculation. After applying random node displacement, the main lobe decreased and other lobes rose in radiation pattern.Secondly, for shaped design of the reflector antenna, an improved aperture phase synthesis method was presented. Based on the assumption that the desired pattern which satisfy amplitude and phase distribution of the aperture can be generated, and the distribution of the specified diameter surface can be generated by a simple shape of the reflector, the method optimized the phase distribution of the near field aperture. Then the node coordinates of the shaped reflecting surface and the amplitude distribution of aperture calculation according to the reflector shape and feed radiation pattern was calcaluted. The proposed method was used to design a pattern synthesis antenna that can irradiate all areas of China.Finally, the surface prediction method of the reflector antenna was studied based on the test data of electrical properties. This paper introduced the concepts of kernel function and linear programming support vector regression. Based on support vector regression method, the surface prediction model of reflector antennas was established by Gauss radial basis function and LPSVR algorithm. The feasibility of the surface prediction model is verified by the simulation data of a truss deployable reflector antenna.