A printed dipole antenna for wideband circular polarization operation

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 1.3 GHz from 2.49 GHz to 3.79 GHz or about 40.6% with respect to the centre frequency at 3.2 GHz, and the 3-dB axial ratio bandwidth is about 800 MHz from 2.92 GHz to 3.72 GHz or 24.2% with respect to the centre frequency at 3.3 GHz.