Abstract
Systematic distortions of reflector antenna surfaces can cause antenna radiation patterns to be undesirably different from those of perfectly smooth reflector surfaces. In this paper, a simulation model for systematic distortions is described which permits an efficient computation of the effects of distortions in the reflector pattern. The model uses a vector diffraction physical optics analysis for the determination of both the copolar and cross-polar fields. An interpolation scheme is also presented for the description of reflector surfaces which are prescribed by discrete points. Representative numerical results are presented for reflectors with sinusoidally and thermally distorted surfaces. Finally, comparisons are made between the measured and calculated patterns of a slowly-varying distorted offset parabolic reflector.
Analyse
Les déformations systématiques de la surface des réflecteurs peuvent modifier sensiblement les diagrammes de rayonnement par rapport à ceux issus de réflecteurs parfaitement lisses. Cet article décrit un modèle de simulation des déformations systématiques permettant un calcul efficace des effets des déformations sur le diagramme de rayonnement du réflecteur. Le modèle utilise une formulation vectorielle de la diffraction en optique physique pour la détermination des champs copolaire et contrapolaire. L’auteur propose un procédé d’interpolation pour la description des surfaces de réflecteurs définies par des points discrets. Des résultats numériques représentatifs sont donnés pour des réflecteurs dont la surface présente des déformations sinusoïdales ou thermiques. Enfin la comparaison est faite entre les diagrammes de rayonnement calculé et mesuré pour un réflecteur parabolique à source décalée, affectée d’une déformation à variation lente.
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The research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (nasa).
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Rahmat-Samii, Y. Effects of deterministic surface distortions on reflector antenna performance. Ann. Télécommun. 40, 350–360 (1985). https://doi.org/10.1007/BF03003643
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DOI: https://doi.org/10.1007/BF03003643
Key words
- Reflector antenna
- Deformation
- Radiation pattern
- Reflecting surface
- Offset feed antenna
- Vector method
- Interpolation
- Wave optics
- Digital method