根据移动卫星通信和卫星导航定位中对天线宽波束、圆极化和低仰角增益等要求，设计了一种新型的双频四臂螺旋天线，通过将工作于不同频段的两副结构类似的天线以内外共轴的方式形成一个整体来实现双频工作。天线通过开槽线巴伦实现平衡馈电，利用四臂螺旋自身的结构特点构造了90°自相移结构，获得了较好的宽波束圆极化特性。测试结果表明。实测和仿真结果基本一致，天线在两个频段都实现了较好的宽波束圆极化特性。%The satellite communication systems and satellite navigation systems usually require the anten- na to provide wide beam, circular polarization and high gain at low elevation. Based on these needs, a new type of dual-band wide-beam quadrifilar helix antenna is designed. The available dual-band is a- chieved by putting two similar antenna structures operated at different frequency bands in an inner and outer coaxial way, and fed by a split coax balun. A 90° seff-phased structure is formed through the quadrifilar helix characteristic to obtain a wide beam and good circular polarization performance. Experi- mental results of the fabricated antenna show that, the measured results are consistent with the simulated ones, and the antenna can provide good wide-beam circular polarization characteristics in both frequency bands.
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