This study presents the design of an efficient, moderately high gain and portable antenna operating at 58.27 MHz. The proposed antenna is a multilayered hemi-cylindrical shaped structure, which works on the principle of resonant inductive coupling using a multi-turn loop. An equivalent circuit, which takes into account the near field coupling effects, is also developed. The proposed antenna is electrically small with a finite ground plane with $ka \simeq 0.28$ka≃0.28 and has an overall volume of 0.038λ ₀ × 0.058λ ₀ × 0.058λ ₀ . The antenna exhibits a gain of 3.43 dBi and an efficiency of 92.5% as obtained from measured results at the resonant frequency. The measured fractional bandwidth and the Q _ratio of the antenna are 0.547 and 8.647%, respectively. The results obtained from electromagnetic simulation matches with that obtained from the equivalent circuit and the measured results. The antenna can operate at the lower very high frequency (VHF) frequency range for applications, which require electrically small portable antennas such as underground mine communication.

中文翻译：

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用于地下矿山通信的电学小型半圆柱形多层甚高频天线

这项研究提出了工作在58.27 MHz的高效，中等增益和便携式天线的设计。拟议中的天线是多层半圆柱形结构，其工作原理是利用多匝回路实现谐振感应耦合。还开发了一种考虑了近场耦合效应的等效电路。拟议的天线在电气上很小，接地平面有限，$ ka \ simeq 0.28 $ķ一种≃0.28并且具有0.038λ的总体积 ₀ ×0.058λ ₀ ×0.058λ ₀ 。根据在谐振频率下的测量结果，该天线的增益为3.43 dBi，效率为92.5％。测得的分数带宽和问 天线的_比率分别为0.547和8.647％。从电磁仿真获得的结果与从等效电路和测量结果获得的结果相匹配。该天线可以在较低的甚高频（VHF）频率范围内工作，以用于需要电小型便携式天线（例如地下矿山通信）的应用。