一种新型宽带圆极化微带天线的设计

Design of a New Circular Polarization Broadband Microstrip Antenna

采用四层介质耦合馈电结构,设计了一种新型宽带圆极化微带天线。选择方形倒角贴片为辐射单元,采用开路微带线耦合馈电,附加一并联调谐枝节,不仅拓宽了阻抗匹配带宽,而且有效改善了天线的圆极化轴比特性。利用这样的圆极化单元,组成四元圆极化天线阵。经过计算和测试,天线工作于3.0GHz时,单元和天线阵的阻抗带宽分别达到了14.3%和31.3%(VSWR<2),3dB轴比带宽分别达到11.67%和29.87%。这种结构的圆极化天线阵在无线通信等领域应用前景广阔。

A new broadband circular polarization microstrip antenna fed by electromagnetic coupling is designed, which is composed of four substrates. The truncated-corner square patch is selected to be the radiation cell, which is fed by a opened microstrip line with the 50Ωcharacteristic impedance. Through adjusting a turning stub, not only the frequency band is broadened, but also the circular polarization axial ratio is effectively improved. Then four such cells are constructed to be a circular polarization array . Through calculating and testing, the 14.3% and 31.3% （ VSWR 〈 2） bandwidth and 11. 67% and 29.87% 3-dB axial ratio bandwidth are achieved respectively. Such circular polarization array can be used extensively in communications field.