Theoretical and practical limits of superdirective antenna arrays

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• 作者：Abdullah Haskou ; ^{abdullah.haskou@univ-rennes1.fr} ; Ala Sharaiha ; Sylvain Collardey
• 关键词：Superdirective antenna arrays ; Parasitic elements ; Theoretical and practical limits
• 刊名：Comptes Rendus Physique
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：18
• 期：2
• 页码：118-124
• 全文大小：591 K
• 卷排序：18

文摘

Some applications as Wireless Power Transfer (WPT) require compact and directive antennas. However, Electrically Small Antennas (ESAs) have low efficiencies and quasi-isotropic radiation patterns. Superdirective ESA arrays can be an interesting solution to cope with both constraints (the compactness and the directivity). In this paper, the theoretical and practical limits of superdirective antennas will be presented. These limits can be summarized by the directivity sensitivity toward the excitation coefficients changes and the radiation efficiency decrement as the inter-element decreases. The need for negative resistances is also a practical limit for transforming these arrays into parasitic ones. The necessary trade-offs between the antenna total dimensions (the number of elements and the inter-element distance) and the attainable directivity and efficiency are also analyzed throughout this paper.