基于阿基米德螺旋线单元的反射阵列天线设计

Reflectarray Antenna Design Based on Archimedes Spiral Element

本文设计了一种基于阿基米德螺旋结构的新型微带反射阵列单元.单元外圈尺寸固定,通过改变螺旋线向内延伸长度来获得不同的反射相位.经过各结构参数分析,获得一条较为理想的反射相移特性曲线.采用该新型反射单元,设计了一款10×10规模的反射阵列,并建模仿真.仿真结果表明,在工作频率5.8 GHz处,天线的增益为18.7 dBi,1.5-dB增益带宽为22.1%(5.56~6.84 GHz),阻抗带宽为3.8%(5.70~5.92 GHz),主旁瓣比优于-15.0 dB,交叉极化小于-25.8 dB.

This work proposed a novel microstrip reflectarray element based on the Archimedes spiral structure.The dimension of outer ring of the reflective array unit is fixed.Different reflection phases are obtained by changing the inward extension length of the spiral.An ideal reflection phase shift characteristic curve is obtained,after analyzing various structural parameters.A reflectarray simulation model is proposed with 10×10 scale.The simulation results show that at the operating frequency of 5.8 GHz,the antenna gain is 18.7 dBi,with minus 1.5-dB gain bandwidth of 22.1%(5.56~6.84 GHz),and the impedance bandwidth is 3.8%(5.70~5.92 GHz).Meanwhile,the side-lobes level is about minus 15.0 dB below the main lobe,and the cross-polarization is less than minus 25.8 dB.