宽带Ka波段圆极化波导缝隙天线阵的设计

Design of Wideband Ka-Band Circularly Polarized Waveguide Slot Array Antenna

本文设计了一种宽带Ka波段圆极化波导缝隙天线。在波导宽边开并联纵缝,从波导耦合电磁波至其上方开有带一对方片微扰的宽缝的金属腔体圆极化器中,实现圆极化辐射。宽缝可以获得较宽的轴比带宽。本文重点研究了腔体尺寸对天线带宽的影响,优化了阻抗带宽与轴比带宽的匹配。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。天线中心频率处的增益为16.2d B,第一副瓣电平为-17d B,阻抗带宽约为5.57%,相对轴比带宽5.6%。

A novel wideband Ka-band circularly polarized waveguide slot antenna is designed.Parallel longitudinal slots are cut on the broadside of waveguide so that the electromagnetic waves are coupled to the upper metal cavity polarizer,which is cut with wide slot,to realize circularly polarization.Wide Axial Ratio bandwidth can be achieved by wide slot.Parametric studies focus on the effect of the size of metal cavity on bandwidth,so that the impedance bandwidth and AR bandwidth are optimized.Based on the analysis on resonant conductance of the unit,a 1×8 circularly polarized linear array at 35 GHz is designed.Simulated results show that the gain is about 16.2 dB,and the side lobe is-17 dB at the center frequency.The impedance bandwidth is 5.57%,while the bandwidth with AR less than 3 dB is 5.6%.