A Broadband Circularly Polarized Magneto-Electric Dipole Antenna

Abstract

A novel broadband low-profile circularly polarized (CP) magneto-electric (ME) dipole antenna is proposed in the letter. Sharing the same aperture, a pair of electric dipoles (E-dipoles) and a pair of magnetic dipoles (M-dipoles) are combined through four bulges in the corners of the ring. The arms of the ring work as dipole antennas, i.e., E-dipoles, whereas the slots formed by the ring with bulges and the central patch work as slot antennas, i.e., M-dipoles. To realize CP radiation, a pair of vacant-quarter printed rings with short-end microstrip lines is utilized to excite the dipole and slot antennas simultaneously. The measurement results indicate that a wide overlapped impedance bandwidth and axial ratio bandwidth of 2.15–3.35 GHz (1.2 GHz, 43.6%) and a low height of 0.18 λ ₀ at the center frequency of 2.7 GHz are achieved. Moreover, a high gain of 8.5–10.3 dBic and stable radiation patterns with no sidelobes and low back lobes of less than −20 dB are realized for wireless communication.