Gain-Improved Wideband Circularly Polarized Magnetoelectric Dipole Antenna With Parasitic Helix

This communication presents a magnetoelectric (ME) dipole antenna with wideband circularly polarized (CP) and gain-improved performance. Two pairs of perpendicular sub-ME dipoles, which are realized by horizontal and vertical patches, constitute the original ME dipole. By connecting one pair of sub-ME dipole with metallic strip, CP operation is achieved at lower band first. Then, we change the coupling slot from rectangle to cross, which leads to the enhancement of impedance and axial-ratio (AR) bandwidth. Furthermore, a helix with different turn radii and uniform turn spacing is introduced to improve the gain in the whole band. The performance of the proposed design is verified by measured results. The fabricated antenna exhibits a -10 dB impedance bandwidth of 3.33-6.75 GHz, corresponding to 67.9%. Besides, the measured 3 dB AR bandwidth and 3 dB gain bandwidth are 3.6-6.25 GHz (53.8%) and 3.4-5.8 GHz (52.2%), respectively. The proposed design could provide promising application values for wideband wireless communication systems.