A Circularly Polarized Antenna With Wide Axial Ratio Beamwidth

A novel circularly polarized (CP) antenna with wide angular coverage is presented. The proposed antenna is formed by two bowtie patch antennas and two electric dipoles. It can achieve an impedance bandwidth (SWR < 1.6) of 41% and a 3-dB axial ratio bandwidth of 33%. For this design, very stable and symmetrical radiation patterns are obtained. In the axial ratio passband, the 3-dB beamwidth is 85^degplusmn2^deg with a gain of 6.3 dBi plusmn0.3 dBi. The cross polarization is lower than -15 dB over a wide range of angles. For the entire half-power beamwidth, the axial ratio can be kept below 3 dB.