Experimental spherical near-field antenna test facility. Volume 6: Computer simulation studies

A general facility simulator for simulation of antenna measurements by the spherical near field technique is described and results of simulations are presented. It is shown that very high accuracies may be obtained by the spherical near field technique within reasonable requirements to the tolerances of the mechanical and the electrical parts of the set up. The spherical near field test facility at the Technical University of Denmark has been evaluated by simulation. The inaccuracies of the mechanical set-up are shown to cause inaccuracies on determination of the antenna directivity as small as + or - 0.03 db at a directivity level of 45 dBi. The receiver has only been investigated for small test antennas and, typically, the receiver will cause a directivity inaccuracy of + or - 0.07 dB at a level of 21 dBi. The most important sources of inaccuracies are identified and improvements of the set-up are suggested.