一种基于方向图重构机制的宽带宽视角相控阵天线

本文提出了一款风车形方向图可重构单元及其作为阵元的二维平面宽带宽视角扫描相控阵天线。所提出的单馈方向图可重构单元天线由辐射贴片、直流偏置电路以及宽带人工磁导体(Artificial Magnetic Conductor, AMC)反射面构成。其中，辐射贴片为馈电结构可重构的四个Vivaldi缝隙组成的风车形贴片，它能够通过改变PIN二极管的通断以实现宽带内四个端射方向上的波束切换。此外,将AMC反射面加载于辐射结构的后端，使得最大辐射方向由原来的端射方向调整为准端射方向，这样有利于单元天线组阵后的扫描波束能够覆盖到侧射方向。对该天线单元及其构建的8×8均匀平面相控阵天线进行了仿真与分析。仿真结果显示，所设计的阵列天线同时具备了宽带宽视角二维波束扫描性能，其在5.4 ~ 6.1 GHz的工作频带内可以实现±60°范围内的二维波束扫描。同时，阵列的增益波动小于4.3 dB，并且具有较低的旁瓣电平。

A Wideband Wide-Angular Phased Array Base on Pattern-Reconfiguration mechanism

In this paper, a windmill shaped pattern reconfigurable element and its two-dimentional (2-D) wideband wide-angular scanning phased array antenna as an array element are proposed. The proposed single feed pattern reconfigurable unit antenna is composed of radiation patch, DC bias circuits and broadband artificial magnetic conductor (AMC) reflector. The radiation patch composed of four Vivaldi slots is a windmill-shaped patch with a reconfigurable feeding structure. By electrically controlling the PIN diodes integrated in the feeding network, the radiation beam of the element can be switched towards four endfire directions. Besides, the fan-shaped AMC surface is loaded backward the radiation patch. In this situation, the maximum radiation direction is titlted from the original endfire direction into a quasi-endfire direction, which benefits that the main beam of the planar phased array covers the broadside direction. The antenna unit and its construction 8 × 8 uniform planar phased array is simulated and analyzed. The simulation results show that the designed planar array has the performance of wide-band and wide-angle two-dimensional beam scanning,which supports its maxmum scanning angle of ±60° in two main planes from 5.4 to 6.1 GHz. Meanwhile, the gain fluctuation of the array is less than 4.3 dB, and the sidelobe level is quite low.