远场反推变形反射面天线馈源调整量

针对构造最佳吻合抛物面需要事先准确获取反射面变形这一不足，提出一种从远场确定馈源调整量的方法．应用口径场法显式表达出远场对变形反射面最佳吻合参数的灵敏度，将远场和最佳吻合参数用超定线性方程组联系起来，通过测量远区电场，并基于奇异值分解法近似反推出主面变形信息，进而求出馈源调整量．此方法无需事先知道反射面变形信息，两组仿真案例也表明了该方法的正确性和对变形反射面天线补偿的有效性．

Inverse derivation of the adjustment quantity of the distorted reflector antenna feed from a far field

Reflector surface deformation can be compensated by adjusting the feed position. Aiming at the shortcoming of the traditional method that the best-fit paraboloid(BFP) needs to get the accurate reflector deformation beforehand, a method for the determination of the feed adjustment quantity from a far field is presented in this paper. Based on the aperture field method, explicit expressions for the sensitiveness of a far field to best-fit parameters of the distorted reflector are established. Then the best-fit parameters and the far field are linked with an over-determined linear system of equations, and by measuring the far electric field, the reflector deformation can be approximately calculated by the singular value decomposition method, providing guidance for feed adjustment. There is no need to know the reflector distortion in advance in the proposed method. Simulation cases show the correctness of the proposed method and the validity of the compensation for reflector distortion.