Hou Shunhu, Fang Shengliang, Fan Youchen, Li Yuhai, Ma Zhao, Li Jinming
Graduate School, Space Engineering University, Beijing 101416, China.
School of Space Information, Space Engineering University, Beijing 101416, China.
Sensors (Basel). 2024 May 28;24(11):3467. doi: 10.3390/s24113467.
This article proposes a novel fixed-frequency beam scanning leakage antenna based on a liquid crystal metamaterial (LCM) and adopting a metal column embedded microstrip line (MCML) transmission structure. Based on the microstrip line (ML) transmission structure, it was observed that by adding two rows of metal columns in the dielectric substrate, electromagnetic waves can be more effectively transmitted to reduce dissipation, and attenuation loss can be lowered to improve energy radiation efficiency. This antenna couples TEM mode electromagnetic waves into free space by periodically arranging 72 complementary split ring resonators (CSRRs). The LC layer is encapsulated in the transmission medium between the ML and the metal grounding plate. The simulation results show that the antenna can achieve a 106° continuous beam turning from reverse -52° to forward 54° at a frequency of 38 GHz with the holographic principle. In practical applications, beam scanning is achieved by applying a DC bias voltage to the LC layer to adjust the LC dielectric constant. We designed a sector-blocking bias feeder structure to minimize the impact of RF signals on the DC source and avoid the effect of DC bias on antenna radiation. Further comparative experiments revealed that the bias feeder can significantly diminish the influence between the two sources, thereby reducing the impact of bias voltage introduced by LC layer feeding on antenna performance. Compared with existing approaches, the antenna array simultaneously combines the advantages of high frequency band, high gain, wide beam scanning range, and low loss.
本文提出了一种基于液晶超材料（LCM）并采用金属柱嵌入式微带线（MCML）传输结构的新型固定频率波束扫描漏波天线。基于微带线（ML）传输结构，研究发现，通过在介质基板中添加两排金属柱，可以更有效地传输电磁波以减少损耗，并降低衰减损耗以提高能量辐射效率。该天线通过周期性排列72个互补开口环谐振器（CSRR）将TEM模式电磁波耦合到自由空间中。LC层封装在ML与金属接地板之间的传输介质中。仿真结果表明，该天线利用全息原理在38GHz频率下可实现从-52°反向到54°正向的106°连续波束转向。在实际应用中，通过向LC层施加直流偏置电压来调整LC介电常数以实现波束扫描。我们设计了一种扇形阻塞偏置馈线结构，以最小化射频信号对直流源的影响，并避免直流偏置对天线辐射的影响。进一步的对比实验表明，该偏置馈线可显著减小两个源之间的相互影响，从而降低LC层馈电引入的偏置电压对天线性能的影响。与现有方法相比，该天线阵列同时具备高频段、高增益、宽波束扫描范围和低损耗等优点。
