Ka波段SIW馈电的圆极化贴片阵列天线设计

Design of Circularly Polarized Patch Array Feed through SIW

本文提出了一种基于基片集成波导(SIW)馈电的Ka波段圆极化贴片阵列天线。采用SIW作为馈电波导,在上方金属层开馈电纵缝,缝隙上加载了一种改进型的切角贴片产生圆极化辐射。馈电纵缝和辐射贴片可视作SIW上加载的一个并列谐振单元,单元圆极化特性主要取决于切角贴片,而单元的导纳特性可以通过馈电缝隙的长度和偏移量来调节。在提取单元谐振电导的基础上,设计了工作在35GHz的1′8圆极化波导缝隙阵列。最终采用渐变微带线到SIW的过渡实现阵列的微带线馈电。天线仿真得到中心频率处的增益为14.1dB,第一副瓣电平为14.2dB,阻抗带宽约为8.8%,相对轴比带宽(AR)约为3.8%。

A circular polarized patch array antenna based on SIW is proposed.SIW is used as feed waveguide,circularly polarized is achieved by loading a spit truncated patch array on a longitude slotted metal layer on the SIW.Feeding longitudinal slot and the radiating patch can be regarded as a parallel resonant unit loaded on the SIW.Unit circular polarization characteristics mainly depend on the split truncated patch,while the unit conductance characteristics can be realized by adjusting the length and the offset of the feeding slot.Based on the analysis on resonant conductance of the unit,a 1-by-8 circularly polarized linear array at 35 GHz is developed.The measured results show that the gain is about 14.1 dB with side lobe-14.2 dB at the center frequency.The impedance bandwidth is 8.8%,while the bandwidth with AR less than 3 dB is 3.8%.