The Open Electrical & Electronic Engineering Journal

2013, 7 : 21-30
Published online 2013 April 19. DOI: 10.2174/1874129001307010021
Publisher ID: TOEEJ-7-21

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

F. D'Agostino , F. Ferrara , C. Gennarelli , R. Guerriero and M. Migliozzi
Dipartimento di Ingegneria Industriale (D.I.In.), University of Salerno, Via Ponte Don Melillo, 84084 Fisciano (SA), Italy.

ABSTRACT

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.

Keywords:

Antenna measurements, Direct near-field – far-field transformations, Helicoidal scanning.