The theory as well as numerical and experimental results are presented for a superdirective array composed of closely spaced electrically small resonant magnetic dipole elements. The array operates on a metal ground plane and can exhibit a maximum directivity of 11.5 dBi, 15.2 dBi, and 17.8 dBi (including 3 dB due to the ground plane), for 2, 3, and 4 magnetic dipoles, respectively. The array is self-resonant and is directly excited by a 50-ohm coaxial cable through the ground plane. The array radiates essentially the $ertmuert=1$ spherical modes, which, despite a narrow bandwidth, makes it an excellent first-order probe for spherical near-field antenna measurements at low frequencies.
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机译：介绍了由紧密排列的电小谐振磁偶极子元件组成的超指向性阵列的理论以及数值和实验结果。该阵列在金属接地平面上运行，对于2、3和4个磁偶极子，其最大方向性分别为11.5 dBi，15.2 dBi和17.8 dBi（由于接地平面而包括3 dB）。该阵列是自谐振的，并通过接地平面的50欧姆同轴电缆直接激励。该阵列基本上辐射$ vert mu vert = 1 $球形模式，尽管带宽较窄，但它还是用于低频低频球形近场天线测量的优秀一阶探头。
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