Evaluation of the measurement equipment for electromagnetic fields in the near-field and far-field zones

2002 ◽  
Author(s):  
M.S. Israel ◽  
P.D. Chobanov
Keyword(s):  
Electromagnetic Fields ◽  
Near Field ◽  
Measurement Equipment ◽  
Far Field

Nonredundant Representation of the Electromagnetic Fields Over a Cylinder with Application to the Near-Field Far-Field Transformation

1996 ◽  
Vol 16 (3) ◽  
pp. 273-290 ◽  
Author(s):  
Ovidio M. Bucci ◽  
Claudio Gennarelli ◽  
Giovanni Riccio ◽  
Vito Speranza ◽  
Catello Savarese
Keyword(s):  
Electromagnetic Fields ◽  
Near Field ◽  
Far Field ◽  
Field Transformation

scholarly journals An Innovative Direct NF-FF Transformation Technique with Helicoidal Scanning

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Francesco D’Agostino ◽  
Flaminio Ferrara ◽  
Claudio Gennarelli ◽  
Rocco Guerriero ◽  
Massimo Migliozzi
Keyword(s):  
Electromagnetic Fields ◽  
Field Data ◽  
Near Field ◽  
Transverse Dimension ◽  
Computational Effort ◽  
Far Field ◽  
Transformation Technique ◽  
Spherical Antenna ◽  
Field Transformation ◽  
Mechanical Scanning

A direct near-field-far-field transformation with helicoidal scanning is developed. It is based on the nonredundant sampling representation of electromagnetic fields and uses a spherical antenna modelling to determine the number of helix turns. Moreover, the number of voltage samples on each of them is fixed by the maximum transverse dimension of the antenna, both to simplify the mechanical scanning and to reduce the computational effort. This technique allows the evaluation of the antenna far field directly from a minimum set of near-field data without interpolating them. Although the number of near-field data employed by the developed technique is slightly increased with respect to that required by rigorously applying the nonredundant sampling representation on the helix, it is still remarkably smaller than that needed by the standard near-field-far-field transformation with cylindrical scanning. The effectiveness of the technique is assessed by numerical and experimental results.

scholarly journals Effective Antenna Modellings for NF-FF Transformations with Spherical Scanning Using the Minimum Number of Data

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Francesco D'Agostino ◽  
Flaminio Ferrara ◽  
Claudio Gennarelli ◽  
Rocco Guerriero ◽  
Massimo Migliozzi
Keyword(s):  
Electromagnetic Fields ◽  
Near Field ◽  
Two Dimensions ◽  
Geometric Parameters ◽  
Optimal Sampling ◽  
Far Field ◽  
Aperture Diameter ◽  
The Third ◽  
Numerical Tests ◽  
Minimum Number

Two efficient probe-compensated near-field-far-field transformations with spherical scanning for antennas having two dimensions very different from the third one are here developed. They rely on the nonredundant sampling representations of the electromagnetic fields and on the optimal sampling interpolation expansions, and use effective antenna modellings. In particular, an antenna with a predominant dimension is no longer considered as enclosed in a sphere but in a cylinder ended in two half spheres, whereas a surface formed by two circular “bowls” with the same aperture diameter but different lateral bends is adopted to shape an antenna with two predominant dimensions. These modellings are able to fit very well a lot of antennas by properly setting their geometric parameters. It is so possible to remarkably lower the number of data to be acquired, thus significantly reducing the measurement time. Numerical tests assessing the accuracy and the robustness of the techniques are reported.

scholarly journals An Efficient Transformation Technique for the Direct Recovering of the Antenna Far-Field Pattern from Near-Field Measurements Collected along a Helix

2013 ◽  
Vol 7 (1) ◽  
pp. 21-30 ◽  
Author(s):  
F. D'Agostino ◽  
F. Ferrara ◽  
C. Gennarelli ◽  
R. Guerriero ◽  
M. Migliozzi
Keyword(s):  
Electromagnetic Fields ◽  
Field Data ◽  
Near Field ◽  
Field Measurements ◽  
Field Pattern ◽  
Far Field ◽  
Transformation Technique ◽  
Computational Burden ◽  
Field Transformation ◽  
Far Field Pattern

A near-field to far-field transformation technique with helicoidal scanning for elongated antennas, which allows the evaluation of the antenna far-field pattern in any cut plane directly from a nonredundant number of near-field data without interpolating them, is developed in this paper. It is based on the nonredundant sampling representations of electromagnetic fields and employs a flexible source modelling suitable for long antennas to determine the number of helix turns. The number of near-field measurements on each turn is on the contrary dictated by the minimum cylinder rule, as in the classical cylindrical scanning, in order to reduce the computational burden and to simplify the scanning from the mechanical viewpoint. Some numerical and experimental results assessing the effectiveness of the proposed technique are reported.

Magnetic Tag Antenna for UHF Near-field and Far-Field RFID Applications

2015 ◽  
Vol 5 (2) ◽  
pp. 119
Author(s):  
Mondher Dhaouadi ◽  
M. Mabrouk ◽  
T. Vuong ◽  
A. Ghazel
Keyword(s):  
Near Field ◽  
Far Field ◽  
Rfid Applications
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