一款双频双宽带双圆极化Fabry⁃Perot谐振腔天线

Dual⁃wideband dual circularly polarized Fabry⁃Perot resonator cavity antenna

文中设计了一款双频双宽带双圆极化的法布里⁃珀罗(FP)谐振腔天线。传统的FP天线具有高增益特性但是难以实现宽带及双频带工作,为了改善其性能,提出一种具有双频正相位梯度的部分反射表面,利用其正相位梯度特性弥补电磁波频率升高带来的空间相位变化,从而在较宽的带宽内满足FP天线的谐振条件以实现宽带辐射。通过加载寄生贴片以及缝隙耦合馈电的方式设计宽带圆极化馈源,并且采用人工磁导体结构替代传统的金属地板,在同一谐振腔高度下满足两个频段的谐振条件,简化了双频FP天线的结构。全波仿真结果表明,所提出的FP天线3 dB轴比带宽分别为10.1%和13.8%,峰值增益达到12.45 dBi和11.9 dBi,3 dB增益带宽分别为11.5%和14.8%。

In this paper,a dual⁃wideband dual circularly polarized Fabry⁃Perot(FP)resonator cavity antenna is designed.The traditional FP antenna is of high gain characteristics,but it fails to achieve broadband and dual⁃band operation.In order to improve the performance of the traditional FP antenna,a partially reflective surface with dual⁃band positive phase gradient is proposed.The positive phase gradient characteristics of partially reflective surface are used to compensate for the spatial phase change caused by the increase of electromagnetic wave frequency,which meets the resonance conditions of FP antenna in a wide bandwidth and achieve broadband radiation.The broadband circularly polarized feed is designed by means of loading parasitic patches and gap coupling feeds,and the artificial magnetic conductor structure is used to replace the traditional metal floor,which meets the resonance conditions of the two frequency bands at the same height of resonant cavity and simplifies the structure of the dual⁃band FP antenna.The full⁃wave simulation results show that the 3 dB axial ratio bandwidth of the proposed FP antenna is 10.1%and 13.8%,its peak gain reaches 12.45 dBi and 11.9 dBi,and its 3 dB gain bandwidth(GB)is 11.5%and 14.8%,respectively.