Antenna surface measurement by near-field hemispherical scanning and related problems

Abstract

This paper proposed a new method for obtaining the antenna surface deformation by scanning the electric intensity of a near-field hemispherical surface. This method does not need to measure the aperture phase and can realize full attitude measurement with a small scanning area. This study developed a deformation-amplitude equation by combining the differential geometry theory and geometric optics method to establish a direct relation between surface deformation and amplitude distribution. The amplitude deformation equation can be solved using the finite difference method and fast Fourier transform method. Numerical simulation results proved the accuracy of the amplitude deformation equation and the effectiveness of the proposed measurement method. Furthermore, the singular value decomposition method was introduced to reduce the influence of low signal-to-noise ratio on the measurement accuracy.