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Hier finden Sie wissenschaftliche Publikationen aus den FraunhoferInstituten. Fast spherical nearfield measurements on arbitrary surfaces by application of pointwise probe correction to compressed sampling schemes
 Institute of Electrical and Electronics Engineers IEEE; Antenna Measurement Techniques Association AMTA: 41st Annual Symposium of the Antenna Measurement Techniques Association, AMTA 2019. Proceedings : October 611, 2019, San Diego, California, USA Piscataway, NJ: IEEE, 2019 ISBN: 9781728130019 ISBN: 9781728145273 ISBN: 9781728145259 6 S. 
 Antenna Measurement Techniques Association (AMTA Annual Meeting and Symposium) <41, 2019, San Diego/Calif.> 

 Englisch 
 Konferenzbeitrag 
 Fraunhofer FHR () 
Abstract
The major disadvantage of Spherical NearField (SNF) measurements is their long acquisition time. To calculate the Antenna Under Test’s (AUT) farfield radiation characteristics, a sphere containing the AUT must be sampled. Classically, equiangular sampling is chosen, being the resulting sphere heavily oversampled. Since the Spherical Mode Coefficients (SMCs) are usually sparse, an approach to reduce the measurement time of SNF measurements is to undersample the sphere and to reconstruct the SMCs using compressedsensing techniques. Using a sampling matrix with a minimum mutual coherence for the given bases of the SMCs increases the probability of recovery. The SMCs are defined in the basis of the spherical harmonics or Wigner Dfunctions, which limits the geometries in which this technique can be applied. In this work, the application of pointwise probe correction for the description of nonspherical surfaces in the WignerD basis expansion is suggested. The chosen sampling points are radially projected onto the measurement surface and the new distance to each point is calculated. New equivalent probe response coefficients are calculated per measurement point according to their distance to the AUT. To compensate for different orientations other than the probe pointing to the AUT’s minimum sphere’s center, the probe’s SMCs are rotated to reflect the real orientation of the probe at each point prior to the calculation of the probe response coefficients. Although more computationally demanding than classical probe correction, this technique allows measurements with different, potentially faster geometries and enables the application of compressed sensing to other, nonspherical conventional scanning systems.