The bi-polar planar near-field measurement technique, part II: near-field to far-field transformation and holographic imaging methods

1994 ◽  
Vol 42 (2) ◽  
pp. 196-204 ◽  
Author(s):  
R.G. Yaccarino ◽  
Y. Rahmat-Samii ◽  
L.I. Williams
Keyword(s):  
Measurement Technique ◽  
Field Measurement ◽  
Near Field ◽  
Far Field ◽  
Imaging Methods ◽  
Holographic Imaging ◽  
Field Transformation ◽  
Near Field Measurement

scholarly journals EMC Measurement Setup Based on Near-Field Multiprobe System

2021 ◽  
Author(s):  
Rubén Tena Sánchez ◽  
Lars Jacob Foged ◽  
Manuel Sierra Castañer
Keyword(s):  
Field Measurement ◽  
Software Defined Radio ◽  
Near Field ◽  
Cost Effective ◽  
Far Field ◽  
Measurement Systems ◽  
Radio Receivers ◽  
Space Reduction ◽  
Field Transformation ◽  
Near Field Measurement

Multiprobe spherical near-field measurement is a potent tool for fast and accurate characterization of electrical properties of antennas. The use of fast switching in one axis, an azimuth positioner, and a near- to far-field transformation allows a substantial time reduction in antenna measurements while maintaining high-quality results. On the other hand, conventional emissions EMC measurement systems are typically based on detecting the radiated spurious emissions by a device at different frequencies. The systems usually work in far-field (or quasi-far-field conditions), performing the measurements either at 3 or 10 meters. Measurements under these conditions take space and time. Moreover, the systems are not cost-effective for pre-compliance purposes where pre-testing of the device should provide valuable information and confidence about the DUT before performing a compliance test. This chapter analyzes the possibility of cost and space reduction for EMC systems based on multiprobe near-field measurement systems in combination with OTA (over the air measurements), reference-less systems, spherical near-field transformation, phase reconstruction, modal filtering, source reconstruction, and software-defined radio receivers.

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

2013 ◽  
Vol 11 ◽  
pp. 47-54
Author(s):  
R. A. M. Mauermayer ◽  
T. F. Eibert
Keyword(s):  
Plane Wave ◽  
Antenna Array ◽  
Field Measurement ◽  
Near Field ◽  
Measurement Data ◽  
Synthesis Process ◽  
Far Field ◽  
Field Transformation ◽  
Wave Synthesis ◽  
Near Field Measurement

Abstract. 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.

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