基于HIS的低剖面宽角扫描相控阵天线设计

Design of Low Profile Wide Angle Scanning Phased Array Antenna Based on HIS

本文设计了工作于1.9~3.2 GHz的宽波束宽带蝶形偶极子,增加四分之一波长短路柱,改善匹配拓展阻抗带宽,将蝶形偶极子组成一维八元线阵,研究波束扫描角度和阻抗带宽。此外,设计了一种矩形HIS(High Impedance Surface)单元并研究其带隙与同相反射特性。将HIS加载到阵列上,利用HIS的同相反射特性降低其剖面高度。同时,由于HIS对表面波的影响,将相控阵的扫描角度进一步拓展。结果表明,加载HIS比未加载HIS相控阵扫描至±60°时的主瓣增益和副瓣电平分别提高了3 dB和12 dB,并且交叉极化鉴别率XPD(Cross Polarization Discrimination)可以提高13 dB,加载HIS的相控阵在主瓣增益下降3 dB以内可以达到±65°的扫描角度。

In this paper,a wide beam wideband butterfly dipole operating at 1.9~3.2 GHz is proposed.A quarter wave long short comlumn is added to improve the matching and to expand the impedance bandwidth.One-dimension eight elements linear array is formed with butterfly dipole to study the beam scanning angle and impedance bandwidth.In addition,a rectangular HIS(high impedance surface)element is designed and its band gap and in-phase reflection characteristics are studied.Loading HIS on the array,the profile height is greatly reduced by utilizing the in-phase reflection characteristic of HIS.At the same time,due to the influence of HIS on the surface wave,the scanning angle of phased array can be further expanded.The results show that the gain of main lobe and the level of sidelobe are increased by 3 dB and 12 dB respectively when the phased array is scanned to±60°with HIS,and the XPD(cross polarization discrimination)can be increased by 13 dB,the scanning angle of the phased array with HIS can reach±65°when the main lobe gain decreases by 3 dB.