Calculating Arbitrarily Located Sampling Data From Quiet Zone Spherical Near-Field Scanning Measurements

Amplitude and phase distribution inside the quiet zone (QZ) of a far-field antenna measurement chamber are important indicators for the quality of antenna measurements therein. Both amplitude and phase can be further subdivided into intuitive quality parameters such as linear taper, parabolic taper, and ripple. In order to retrieve these parameters from QZ spherical near-field measurements, the transmission formula is adapted to the case where the output signal of a virtually positioned output probe-antenna can be calculated on arbitrary locations inside the QZ. The output probe-antenna can be a measured or theoretically defined antenna and can be rotated in any direction of interest. This paper will show that this method provides similar results as industry standard linear field-probing by comparing amplitude taper and ripple extracted from both measurements. Further the advantages of using QZ spherical near-field scanning (QZSNFS) in combination with the adapted output transmission formula will be shown by calculating multiple projections not available by standard field-probing.