基于液态金属的跨波段超宽带极化转换超表面

Liquid metal based metasurface for cross-band and ultra-wideband polarization conversion

在无线通信领域,电磁波传播和极化方向调控对特定信号的识别与接收具有重要意义。提出了一种基于液态金属材质的跨X(8~12 GHz)和Ku(12~18 GHz)波段超宽带极化转换电磁超表面,具有宽频带、高极化转换率、体积小、无机械疲劳损伤、易共形、成本低等优点。该超表面能够实现从7.595 GHz到17.712 GHz超宽带范围内交叉极化转换或宽带圆极化转换的功能。当阶梯状液态金属结构宽度为1.6 mm时,在相对带宽为79.9%的7.595~17.712 GHz频带上,超表面极化转换率优于90%,具有共极化向交叉极化转换的功能。当阶梯状液态金属结构宽度为0.3 mm时,在相对带宽为12.30%的10.864~12.288 GHz频带上,超表面具有线极化向圆极化转换的功能;在相对带宽为3.54%的7.328~7.592 GHz频带上,超表面的极化转换率优于90%,具有共极化向交叉极化转换的功能。样品制备及其极化转换特性测试结果表明:实验结果与仿真结果的相对误差为4.20%,理论设计与实验验证结果一致,进而验证了的跨X和Ku波段超宽带极化转换电磁超表面的多功能性和有效性。

In wireless communication,controlling electromagnetic wave propagation and polarization direction is crucial for signal detection and reception.This study introduces a liquid metal-based electromagnetic metasurface for polarization conversion in the X(8-12 GHz)and Ku(12-18 GHz)bands.It offers benefits like ultra-wideband performance,high polarization conversion ratio,compactness,durability against mechanical fatigue,flexibility,and affordability.The metasurface consists of a periodic arrangement with a top step-shaped liquid metal structure,a middle dielectric layer,and a bottom copper foil,capable of ultra-wideband cross-polarization conversion or wideband circular polarization conversion from 7.595 GHz to 17.712 GHz.With a 1.6 mm wide step-shaped liquid metal structure,it achieves over 90% polarization conversion ratio across 7.595-17.712 GHz with a 79.9% relative bandwidth,enabling co-polarization to cross-polarization conversion.At a 0.3mm structure width,it converts linear to circular polarization between 10.864-12.288 GHz with a 12.30% relative bandwidth.Additionally,in the 7.328-7.592 GHz band with a 3.54%relative bandwidth,it maintains over 90% polarization conversion ratio,facilitating co-to cross-polarization conversion.Experimental sample tests reveal a 4.20% relative error between experimental and simulated results,indicating strong theoretical and experimental correlation,thus confirming the metasurface's versatility and effectiveness.