Range-field plane wave model determined from spherical probling data

摘要

Previous researchers have demonstrated the ability to probe the rnage field illuminating an antenna under test (AUT) on the surface of a sphere and to calculate the spherical wave coefficients from these measurements. This paper describes a techniqje for obtaining a plane wave model of the range using these spherical wave coefficients. An algorithm for creating this pane wave model is presented and a plane wave model for a measured range field is shown. A plane wave spectrum of thr range field is calculated and the directions of the largest peaks of this plane wave spectrum are used as initial guesses for the direction of plane w aves. The directions of incidence of these plane waves are optimized such that the least square error between the range spherical wave coefficients and plane wave model spherical wave c oefficients is minimized. An example of a measured range is presented which consists of a horn range antenna and a smalloer horn as an extraneous source located approximately 20 degrees off the range axis. The plane wave model is used in a range compensation algorithm described in a companion paper.