Quantifying The Effect Of Position Errors In Spherical Near-Field Measurements
Authors: Allen C. Newell, Greg Hindman
Publication: AMTA 1998
Copyright Owner: NSI-MI Technologies
Concise mathematical relations have been derived for Planar Near-Field measurements that quantify the effects of x, y and z-position errors on antenna parameters such as gain, sidelobe level, pointing, and cross polarization. Because of the complexity of the theory, similar relations for spherical near-field measurements have not been developed. The requirements for the spherical coordinate system are generally defined in terms of the alignment parameters such as orthogonality and intersection of axes, θ-zero, xzero and y-zero rather than individual errors in θ, φ and r. Mechanical, optical and electrical techniques have been developed to achieve these alignments. This paper will report on the development of methods to estimate the antenna parameter errors that will result from spherical alignment errors for typical antennas.