C/X双频双圆极化共口径微带天线设计

Design of C/X dual band and dual circularly polarized shared-aperture microstrip antenna

设计实现了一款C/X双频双圆极化共口径微带天线,在C/X频段均能以双圆极化方式工作,有效提高了天线的口径利用率。采用寄生结构和L型探针耦合馈电拓展了天线的阻抗带宽;以嵌套方式将X波段天线置于C波段天线的间隙处实现了共口径设计;通过对称反相馈电技术实现了良好的交叉极化比。测试结果表明,C波段的阻抗带宽和3 dB轴比带宽分别大于23%和17%;X波段的阻抗带宽和3 dB轴比带宽分别大于28%和18%;测试频点处的交叉极化比均大于25 dB。

A dual band dual circularly polarized shared-aperture microstrip antenna is designed and fabricated,which can operate in the dual circular polarization mode in the C/X band,and the aperture utilization rate of the antenna is effectively improved.The parasitic structure and the L-shaped probe are applied to improve the impedance bandwidth.The shared aperture design is realized by placing the X-band antenna in the gap of the C-band antenna.The good cross-polarization ratio is realized by the symmetrical inversed phase feeding technique.The measurement results show that the impedance bandwidth and 3 dB axial ratio bandwidth of C-band are greater than 23%and 17%,respectively.The impedance bandwidth and 3 dB axial ratio bandwidth of X-band are greater than 28%and 18%respectively.The cross-polarization ratio at the test frequency points is greater than 25 dB.