EXPERIMENTAL VERIFICATION OF NONUNIFORM SAMPUNG TECHNIQUE FOR ANTENNA FAR-FIELD CONSTRUCTION

Abstract

A recently developed antenna pattern reconstruction technique using the nonuniform sampling algorithm is able to construct the antenna far-field patterns from a set of non-uniformly distributed amplitude and phase samples. This paper presents the application of this technique to an actual antenna measurement performed at JPL. The 1.47-meter Viking and a 1-meter reflectors operating at X-band were both measured. A conical-cut approach is used to generate nonuniformly distributed samples. The far-field patterns of these two antennas are reconstructed from the measured data using a developed computer program based on the nonuniform sampling algorithm. An overlapping “Window Concept” is also applied in the far-field reconstruction process to avoid measurement error spreading. The results of the reconstructed patterns are compared with the standard azimuth-cut patterns. The effects of selection of various phase reference points in applying the nonuniform sampling technique are demonstrated through a numerical simulation of the Viking antenna. This technique is anticipated to be used for the measurement of large antennas.