【摘要】 椭圆螺旋天线的结构比传统的圆柱螺旋天线更加适合于卫星通信的终端,然而由于其圆极化特性变差而限制了其广泛应用。把改善轴向模螺旋天线辐射特性的两种方法结合起来应用于椭圆螺旋天线,提出了带有附加螺旋线的变升角轴向模椭圆螺旋天线。以一个5圈、短轴长轴之比为0.65的椭圆螺旋天线为例,用FEKO软件对其辐射特性进行了仿真。结果表明,这种方法提高了椭圆螺旋天线的方向性系数,同时具有较好的圆极化特性。在2.2~4.2 GHz频率范围内,最高增益为12.86 dB,比单绕均匀升角的椭圆螺旋天线提高了1.2 dB。更多还原

【Abstract】 Elliptical helical antennas are more suitable for satellite communications than traditional cylindrical helical antennas,whereas the circular polarization performance deteriorates,which restricts their wide applications.Two methods of improving radiation performance of axial mode helical antennas are combined and applied to elliptical helical antennas and an elliptical helical antenna with a parasitic helix wire and a variable pitch angle is proposed.A 5 coils elliptical helical antenna whose ratio of the short axis to the long axis is 0.65 is simulated by the FEKO software as an instance.It is found that the directivity is improved.Meanwhile,it has good circular polarization performance.The highest power gain is 12.86 dB within the band width of 2.2~4.2 GHz,which is 1.2 dB higher than that of a monofilar uniform elliptical helical antenna.更多还原