New diagnostic tool improves antenna designs

A diagnostic tool that reconstructs the extreme near-field and surface currents of an antenna under test (AUT) using planar and 3D reconstruction techniques has been successfully validated through ESA´s ARTES Programme.

Based on the radiated field measured in anechoic chambers, the DIATOOL traces errors and can improve antenna designs by providing valuable information about the antenna performance. This software performs efficient antenna diagnostics in the extreme near-field region of the antenna, saving precious time in the antenna testing process.

Working in cooperation with TICRA (DK) the developer of DIATOOL, the ARTES project focused on two field reconstruction methods:

  • 3D reconstruction technique: an inverse Method of Moments algorithm based on smooth polynomial basis functions and curved geometry modelling, combined with a robust solution algorithm. This technique makes it possible to reconstruct the field on arbitrary 3D surfaces enclosing the AUT.
  • Planar reconstruction technique: a modal approach involving a spherical wave-to-plane wave transformation, taking into account part of the evanescent waves of the plane wave spectrum. The field can be reconstructed on planar surfaces in front of or around the AUT.

Both techniques can provide a high resolution of the reconstructed field, whereas the resolution achieved in practice is limited by the signal-to-noise ratio of the measured data. The software has been successfully validated by a series of test cases involving real measurement data of antennas affected by mechanical and electrical errors.

DIATOOL targets general antenna diagnostics applications including identification of array element failure, surface errors and feeding network imperfections such as leaking cables; all of which provide unexpected anomalies in the radiation pattern.
It provides computation of clean antenna patterns where currents on cables, mounting fixtures or selected areas of the reconstruction surface are suppressed. This is essential for measurements of small antennas.

It computes noise-free patterns radiated by the reconstructed currents - the conformal reconstruction surface acts as a physics-based filter that includes the shape of the AUT.

“DIATOOL can be used in the development of antennas for space applications, not only because of the strict requirements and high costs of this market segment, but it also reaches a much wider audience, such as antenna manufacturers and measurement facilities in general,” explains Dietmar Schmitt, Head of the Technologies and Products Division of ESA’s Telecommunications and Integrated Applications directorate. 

TICRA is currently marketing the DIATOOL on its company website. For more information, see the links in the column to the right.

Artist rendition displaying how DIATOOL works courtesy of TICRA 

Event Date

16 February 2012
Published 29 August 2012
Last updated at 29 August 2012 - 14:56