A Wideband Circularly Polarized Slot-Loaded Dipole Antenna with L-Shaped Arms and Parasitic Patches

In this paper, a broadband circularly polarized (CP) antenna based on slot-loaded dipole with L-shaped arms and parasitic patches is proposed and investigated. Circular polarization is initially obtained at the lower frequency by bending the dipole arms into L-shape. To extend the axial ratio (AR) bandwidth, two pairs of parasitic patches are introduced along the orthogonal sections of the L-shaped arms, so that the modified dipole can yield two additional minimum AR points at the center and higher frequency respectively. Meanwhile, to further extend impedance bandwidth and improve CP performance, circular slots are symmetrically embedded into the tapered-end of each arm design. The measured results of the antenna exhibit a 3-dB AR bandwidth of 61.3% within 10-dB return loss bandwidth of 64.0%. Besides, desirable gains across the wide operation band are also demonstrated.