Full Sphere Far-Field Antenna Patterns Obtained Using a Small Planar Scanner and a Poly-Planar Measurement Technique
Authors: Stuart F. Gregson, Clive G. Parini, John McCormick
This paper presents an overview of work carried out in developing the probe-corrected, poly-planar near-field antenna measurement technique. The poly-planar method essentially entails a very general technique for deriving asymptotic far-field antenna patterns from near-field measurements taken over faceted surfaces.
The probe-corrected, poly-planar near-field to far-field transformation, consisting of an innovative hybrid physical optics (PO) plane wave spectrum (PWS) formulation, is summarised, and the importance of correctly reconstructing the normal electric field component for each of the discrete partial scans to the success of this process is highlighted. As an illustration, in this paper the poly-planar technique is deployed to provide coverage over the entire far-field sphere by utilising a small planar facility to acquire two orthogonal tangential near electric field components over the surface of a conceptual cube centred about the antenna under test (AUT). The success of the poly-planar technique is demonstrated through numerical simulation and experimental measurement. A discussion into the limitations of the partial scan technique is also presented.