Analysis and correction of probe location errors in spherical near-field antenna measurement

Abstract

Spherical Near-Field Antenna Measurement is a very important method in characterizing an antenna under test (AUT). The antenna far-field radiating pattern can be derived from a spherical wave expansion of the near-field data. Near-field data used for obtaining the spherical mode coefficients depends on the sampling probes. The probe correction, such as probe calibration, probe compensation, is crucial in near-field to far-field transformation procedure. This paper gives analysis of the influence caused by the deviation of the probe location including radial and tangential direction, and proposes Taylor series as a method to modify the radial location errors. The simulation results show that the modified radiating far-field data with the probe location errors in the radial direction fits better with the ideal situation.