With its high-permittivity in the microwave frequency range, water has the potential as an alternative, inexpensive, bio-friendly and abundant material for many microwave applications such as dielectric resonator antennas and tunable metamaterials. Huygens antennas, composed of single-element structures supporting a special combination of electric and magnetic modes, provide an alternative route for compact and directive antennas. In this work, we investigate a subwavelength water-based Huygens dielectric resonator antenna with strongly excited electric and magnetic dipoles at around 350 MHz. Our antenna leads to the directivity of 6 and a radiation front-to-back ratio of 40.3 dB. Additionally, good matching to the feed-line and the surrounding free space were achieved with a reflection coefficient of −38.3 dB and a total efficiency of 57.8 %. The antenna was fabricated and characterized with excellent agreement between the measurements and the numerical results. Furthermore, several means of tuning the antenna were tested numerically and experimentally. We believe that the proposed water-based Huygens dielectric resonator antenna may serve as an easy–to–fabricate and cheap alternative for the VHF and low end of the UHF bands.

中文翻译：

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水性惠更斯介质谐振天线

由于其在微波频率范围内的高介电常数，对于电介质谐振器天线和可调谐超材料等许多微波应用，水具有替代，廉价，生物友好和丰富的材料的潜力。惠更斯天线由支持电和磁模式的特殊组合的单元素结构组成，为紧凑型和定向天线提供了另一种途径。在这项工作中，我们研究了亚波长水基惠更斯介质谐振器天线，该天线在350 MHz左右具有强烈激发的电和磁偶极子。我们的天线指向性为6，辐射的前后比为40.3 dB。另外，与馈线和周围自由空间的匹配良好，反射系数为-38.3 dB，总效率为57.8％。天线的制造和表征在测量和数值结果之间具有极好的一致性。此外，通过数值和实验测试了几种调谐天线的方法。我们认为，所提议的水基惠更斯介质谐振器天线可以作为VHF和UHF频段低端的易于制造且便宜的替代品。