基于有源超表面的低剖面双波束偏转天线

Low-profile dual-beam steering antenna based on active metasurface

针对传统的波束控制天线剖面高、成本高以及馈电网络复杂的问题,提出了一种基于有源超表面的低剖面双波束偏转天线设计方案。天线由“E”型双波束馈源天线和“7×6”透射型超表面组成。基于电流反转机制,在每个超表面单元上集成2个PIN二极管,实现了1-bit相位分辨率。结合相位补偿定理与远场辐射公式,对超表面单元进行组阵编码,以实现波束调控的性能。该天线的剖面仅为0.162λ0,明显低于其他波束偏转天线。通过设计超表面的偏置网络,实现了天线的双波束偏转。为了验证该方案,对天线进行加工测试。实测结果表明,在工作频率5.47GHz处,双波束的主辐射方向可分别从(ϴ,Φ)=(30°,45°)、(-30°,-41°)偏转到(ϴ,Φ)=(30°,-45°)、(-30°,41°),增益高于8.9 dBi,实测结果与仿真结果具有较好的一致性。所提出的波束控制天线架构为实现低剖面、可调控的多波束天线提供了一种候选方案。

Aiming at the problems of high profile,high cost and complex feed network of traditional beam steering antenna,a design scheme of low-profile dual beam steering antenna based on active metasurface is proposed.The antenna consists of“E”dual beam feeding antenna and“7×6”transmission metasurface.A 1-bit phase resolution is achieved by controlling two PIN diodes on each element based on the current reversal mechanism.Combining the phase compensation theorem and the far-field radiation for-mula,the metasurface unit is arrayed and encoded to achieve the performance of beam control.The profile of the proposed antenna is only 0.162λ0,which is significantly lower than other beam-steering metasurface antennas.The bias network of the metasurface is designed.The dual-beam steering of the antenna is realized.To verify the strategies,prototype of the antenna is fabricated and tested.And the measured results show that the dual-beam can be steered from(ϴ,Φ)=(30°,45°),(-30°,-41°)to(ϴ,Φ)=(30°,-45°),(-30°,41°)at the operating frequency of 5.47 GHz,and the gain is higher than 8.9 dBi.The measured results are in good agreement with the simulation results.The proposed beam control antenna architecture provides a candidate scheme for realizing low-profile and controllable multi-beam antenna.