基于双极化解耦超表面的线转圆极化反射阵列天线设计

Design of Linear-to-Circular Polarized Reflectarray Antenna Using Dual-polarized Decoupled Metasurface Unit

基于极化结构分离的方法,提出了一种新型双极化宽带解耦超表面单元,2种极化的单元可在25~35 GHz实现相位独立连续调控特性。基于此设计了工作在Ka波段偏馈线极化转圆极化反射阵列天线,测试结果表明,阵列可工作在27~34 GHz,最大增益与口径效率分别为30.7 dBic和46.91%,3 dB轴比带宽为23.47%。该双极化解耦反射超表面单元结构简单、工作带宽较宽、口径效率高且副瓣电平在-22 dB以下,在低成本超表面反射阵列的应用中具有极大潜力。提出的双极化解耦方法在目前低成本超表面应用中具有一定的指导价值。

Based on the method of polarization separation of the metasurface structure,a dual-polarized wideband decoupled metasurface element with novel periodic structure is proposed,and both of the sub cells can achieve almost independent and continuous phase with 360°full coverage modulation at 25~35 GHz.Based on this,an offset-feed linear-to-circular polarized reflectarray antenna is designed to operate in Ka-band,and the test results show that the array can operate at 27~34 GHz with a maximum gain of 30.7 dBic,the aperture efficiency of 46.91%and a 3 dB axial-ratio bandwidth of 23.47%.The dual-polarization decoupled metasurface unit has a simple structure,wide operating bandwidth,high aperture efficiency with the side-lobe levels lower than-22 dB,which has great potential for the application of low-cost metasurface reflectarrays.The proposed dual-polarization decoupling method has a guiding value in current low-cost metasurface applications.