A Printed Dipole Antenna For Circular Polarization

In this paper, a novel printed dipole antenna for wideband circular polarization is proposed, which comprises a pair of unequal arms with a small gap which is fed by an L-shaped microstrip feedline through a via. The proposed dipole antenna geometry is arranged so that the orthogonal surface currents have the appropriate phase to provide circular polarization. The effects of various antenna parameters are discussed and analyzed. The results show the impedance bandwidth for return loss below 10 dB is about 1.3GHz from 2.49GHz to 3.79GHz or about 40.6% with respect to the centre frequency at 3.2GHz, and the 3-dB axial ratio bandwidth is about 800MHz from 2.92GHz to 3.72GHz or 24.2% with respect
to the centre frequency at 3.3GHz.