Image Overview
Infinite Ground Plane Antenna Characterization from Limited Groundplane Measurements
The accurate measurement of the infinite ground plane antenna patterns are needed in different applications as discussed in [1-11]. The infinite ground plane condition is difficult to measure on a general antenna due to the finite dimensions of the measurement systems. In spherical near field measurement systems the measured antenna field is described completely by the spherical wave spectrum determined by a near field to farfield transformation [12, 13]. To recover the spherical wave spectrum of the finite ground plane source as if it was placed on an infinite ground plane the field scattered by the finite ground plane edges has to be removed.
In this paper we demonstrate that the technique proposed in [12] can be extended to measurements on general sources on limited ground planes. The method is based on the application of the image theorem on a completely general source placed on a finite size ground plane and is independent of the position and orientation of the source. The novel formulation is based on a spherical wave expansion of the measured pattern and is
particularly suited for spherical near field systems as shown in Figure 1 although easily extended to any measurement system providing full sphere data.
