Zhang Jiahao, Wang Buyun, Yan Sen, Li Wei, Vandenbosch Guy A E
National Key Laboratory of Electromagnetic Energy, Naval University of Engineering, Wuhan 430030, China.
Faculty of Electronics and Information, Xi'an Jiaotong University, Xi'an 710049, China.
Sensors (Basel). 2024 Mar 19;24(6):1956. doi: 10.3390/s24061956.
A metamaterial-inspired varactor-tuned antenna with frequency reconfigurability and pattern diversity is designed. Two different versions of a reconfigurable structure are integrated into a single antenna to excite two different orthogonal patterns, which realizes pattern diversity for MIMO applications. The outer annular Composite Right-/Left-Handed Transmission Line (CRLH-TL) works at the 1 mode and provides a broadside pattern, and the inner circular radiator loaded with split ring resonators (SRR) operates at the 0 mode and radiates an omnidirectional pattern, which realizes pattern diversity. By using surface-mounted varactors, the operating frequencies for the two radiation patterns can be tuned over a wide frequency range, from 1.7 GHz to 2.2 GHz, covering the 1.71-2.17 GHz LTE band, and a low mutual coupling between the two radiators is achieved. The antenna has also been prototyped. The measured results are in good agreement with the simulation results, verifying the proposed concept. The dual-mode MIMO system equipped with the proposed antenna elements is discussed within the context of a 3-D channel model, and it shows a superior array compactness and spectral efficiency (SE) performance compared to scenarios with single-mode elements.
设计了一种受超材料启发的具有频率可重构性和方向图多样性的变容二极管调谐天线。将两种不同版本的可重构结构集成到单个天线中,以激发两种不同的正交方向图,从而实现用于多输入多输出(MIMO)应用的方向图多样性。外部环形复合左右手传输线(CRLH-TL)在1模下工作并提供宽边方向图,而加载有裂环谐振器(SRR)的内部圆形辐射器在0模下工作并辐射全向方向图,从而实现方向图多样性。通过使用表面贴装变容二极管,两种辐射方向图的工作频率可以在1.7 GHz至2.2 GHz的宽频率范围内进行调谐,覆盖1.71 - 2.17 GHz的长期演进(LTE)频段,并且两个辐射器之间实现了低互耦。该天线也已制作成原型。测量结果与仿真结果吻合良好,验证了所提出的概念。在三维信道模型的背景下讨论了配备所提出天线单元的双模MIMO系统,与具有单模单元的场景相比,它显示出优异的阵列紧凑性和频谱效率(SE)性能。