High-index dielectrics are widely used in microwave antennas to control the radiation characteristics. Liquid water, with a high dielectric index at microwave frequency, is an interesting material to achieving tunable functionalities. Here, we demonstrate a water-loaded microwave antenna system that has high loss-tolerance and wideband tunability enabled by fluidity. Our simulation and experimental results show that the resonance frequency can be effectively tuned by the size of loading water. Furthermore, the antenna systems with water loading can achieve high radiation efficiency (>90%) in the ultra-high-frequency (0.3–3 GHz) band. This work brings about opportunities in realistic tunable microwave antenna designs enabled by liquid.

中文翻译：

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超高频段高效水载微波天线

微波天线中广泛使用高指数电介质来控制辐射特性。液态水在微波频率下具有高介电指数，是实现可调功能的有趣材料。在这里，我们展示了一种水载微波天线系统，该系统具有高损耗容限和通过流动性实现的宽带可调性。我们的模拟和实验结果表明，共振频率可以通过加载水的大小进行有效调整。此外，带有水负载的天线系统可以在超高频（0.3-3 GHz）频段实现高辐射效率（> 90％）。这项工作为现实的可调谐微波天线设计带来了机会。