Field Reconstruction and Estimation of the Antenna Support Structure Effect on the Measurement Uncertainty of the BTS1940 Antenna

The 3D reconstruction algorithm of DIATOOL is applied to the BTS1940 antenna, recently measured at the DTU-ESA Spherical Near-Field Antenna Test Facility in Denmark. The antenna was measured mounted on the antenna tower through a custom support structure. The purpose of this paper is to investigate the effect of the support structure on the measured field, by reconstructing the currents induced on the support frame with DIATOOL. The field obtained by filtering these currents is presented. Moreover, the spatial resolution obtained by the 3D reconstruction is discussed and compared with the one obtained by traditional microwave holography and by the inverse Fourier transform of the plane wave spectrum with knowledge of the invisible region.