A fully probe corrected near-field far-field transformation technique employing plane-wave synthesis

• Published in: Advances in radio science Vol. 11; no. 3; pp. 47 - 54
• Main Authors: Mauermayer, R. A. M, Eibert, T. F
• Format: Journal Article
• Language: English
• Published: Katlenburg-Lindau Copernicus GmbH 04-07-2013; Copernicus Publications
• Subjects: Antennas (Electronics); Investigations; Methods
• ISSN: 1684-9973; 1684-9965; 1684-9973
• DOI: 10.5194/ars-11-47-2013

The far-field behavior of an antenna under test (AUT) can be obtained by exciting the AUT with a plane wave. In a measurement, it is sufficient if the plane wave is artificially generated in the vicinity of the AUT. This can be achieved by using a virtual antenna array formed by a probe antenna which is sequentially sampling the radiating near-field of the AUT at different positions. For this purpose, an optimal filter for the virtual antenna array is computed in a preprocessing step. Applying this filter to the near-field measurements, the far-field of the AUT is obtained according to the propagation direction and polarization of the synthesized plane wave. This means that the near-field far-field transformation (NFFFT) is achieved simply by filtering the near-field measurement data. Taking the radiation characteristic of the probe antenna into account during the synthesis process, its influence on the NFFFT is compensated. The principle of the plane-wave synthesis and its application to the NFFFT is presented in detail in this paper. Furthermore, the method is verified by performing transformations of simulated near-field measurement data and of near-field data measured in an anechoic chamber.