A wideband circularly polarized magnetoelectric dipole antenna loaded with parasitic patches

The present research introduces a wideband circularly polarized (CP) magnetoelectric (ME) dipole antenna loaded with parasitic patches. To optimize performance, two pairs of rotationally symmetric rectangular patches are modified through edge chamfering and perturbation loading, producing a CP radiation pattern through a rotating electric field. Subsequently, parasitic patches are strategically positioned around the main radiating elements to extend the axial ratio bandwidth (ARBW). Finally, an additional top-layer substrate is introduced, and part of the parasitic patches surrounding the main radiating patch of the middle-layer substrate is relocated to the top layer. With optimized layout and size adjustment, this modification enhances the gain at both low and high frequencies while shifting the resonant frequency toward lower bands, thereby increasing the relative bandwidth (BW). A simple L-shaped probe feeding structure ensures compact antenna design. Measurement results demonstrate that the designed antenna achieves a 50.5% impedance bandwidth (IBW) covering 20.4-34.2 GHz, a 42.1% 3-dB ARBW spanning 23.2-35.6 GHz, and an overlapping BW of 38.3% (23.2-34.2 GHz). The gain remains stable above 7 dBic across the operating band, peaking at 8.3 dBic.