Distorted reflector antennas: fast and accurate estimation of the surface distortion profile using a new formula

摘要

The high-frequency applicability of reflector antennas is limited by the distortions and the errors on the reflector surface. Different techniques can be used to compensate the degradation of the radiation characteristics if the surface distortion profile is known. Here, a fast and accurate iterative method has been proposed to determine the surface distortion profile which is based on a newly developed variational formula. The surface fitting has been done in the general form of B-splines, which is suitable for both local and global distortions. Different types of the distortions have been studied to check the accuracy of the method. It has been shown that for distortion amplitudes lower than half of wavelength, the proposed algorithm converges with a high accuracy. In comparison with the previous works, the proposed algorithm has higher accuracy and faster convergence and it needs a lower number of far-field measurements. Despite the microwave holography, in the proposed method there is no need to compute the aperture fields.