A simple and novel method for increasing the gain at low elevation angle and widening the beamwidth of quadrifilar helix antenna (QHA) is presented. By adding cross dipoles as a reflector, the right hand circular polarization (RHCP) gain at 5° elevation angle (theta=85°) increases by about 1.4 dB. Parametric studies are performed to explore the performance improvements. An antenna for CNSS (Compass Navigation Satellite System, 2.492 GHz) application is realized based on the studies. The RHCP gain at 5° elevation angle is about 0.6 dB, and 3dB beamwidth is greater than 220°. 10 dB impedance bandwidth is more than 24%, and 3dB axial ratio bandwidth is more than 32%. Measured results are presented to validate the proposed method.
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