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Circular scanning and equivalent magnetic currents for main plane near-field to far-field transformation

✍ Scribed by F. Las-Heras; B. Galocha; J. L. Besada


Publisher
John Wiley and Sons
Year
2002
Tongue
English
Weight
216 KB
Volume
15
Category
Article
ISSN
0894-3370

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✦ Synopsis


Abstract

A method to obtain a main plane far‐field radiation pattern of an antenna under test (AUT) from the correspondent main plane near‐field pattern in a circular scanning is presented. The method is based on the reconstruction of a set of magnetic equivalent currents radiating in free space that represents the AUT. The method can be applied to the measurement of antennas with a linear distribution or with a two‐dimensional distribution under certain considerations that allow to establish integral equations relating field components and one‐dimensional current components. A Levenberg–Marquardt algorithm is used to minimize the least squares error between the fields radiated by the equivalent currents and the measured field. The far field at every aspect angle is obtained from the calculated sources. Calculations of co‐polar and cross‐polar far‐field pattern from measured near‐field data of array antennas have been carried out to compare the proposed method with a full spherical scanning followed by a spherical wave expansion method. Copyright © 2002 John Wiley & Sons, Ltd.